JP3216623B2 - Interferometric SAR method and apparatus, and recording medium recording interferometric SAR program - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interferometric SAR method and apparatus, and a recording medium on which an interferometric SAR program is recorded. The present invention relates to an interferometric SAR method and apparatus for measuring a distance, a target altitude, and a moving speed, and a computer-readable recording medium on which an interferometric SAR program is recorded.

[0002]

2. Description of the Related Art Conventionally, this type of interferometry S
As the AR device, a cross-track type and an along-track type are known. A cross-track interferometric SAR device is provided with two synthetic aperture radars (hereinafter, referred to as SAs) at predetermined positions on a projectile such as an aircraft.
It is called R (Synthetic Aperture Radar). ) Are arranged at a predetermined interval in a direction orthogonal to the traveling direction of the flying object (cross-track direction), and radio waves of the same frequency are emitted from the two SARs toward a target on the ground, and the two SARs
Is used to calculate a target altitude h on the ground using the phase difference between SAR images obtained from the SAR image. Further, the along-track interferometry SAR device arranges two SARs at predetermined positions of a flying object such as an airplane at a predetermined interval in a direction parallel to the traveling direction of the flying object (along track direction), Radio waves of the same frequency are emitted from the two SARs toward the target on the ground surface, and the speed of the target is calculated using a phase difference generated from a time difference when the two SARs observe the target.

[0003] By the way, the cross track interface
The altitude h of the surface target in the SAR SAR device is 2
Distance difference ρ from one SAR to the target₂−ρ₁Do you understand
, The angle θ overlooking the target from the first SAR can be changed.
And calculated based on equations (27) and (28).
It can be. ρ₂−ρ₁= B_y× COSθ-B_x× SINθ… (27) h = Y−ρ₁COSθ (28) where ρ₁Is the distance between the first SAR and the target, ρ₂
Is the distance between the second SAR and the target, B_yIs the first
Altitude distance difference between SAR and second SAR, B _xIs the
The horizontal distance difference between the first SAR and the second SAR, Y is
First SAR altitude. Same in the following equations.

[0004] In the along-track interferometry SAR device, the moving speed of the target on the ground is 2
If the distance difference ρ ₂ −ρ ₁ from the SAR of the table to the target is known, it can be calculated based on the equation (29). ρ ₂ −ρ ₁ = v × T (29) where T is the difference between the time when one of the two SARs observes the target and the time when the other SAR observes the target. Same in the following equations.

[0005] Then, when the frequency of the radio waves radiated from the first SAR and lambda _1, is obtained from the distance [rho ₁ and SAR images received by the first SAR between the first SAR and the target between the waves of the phase phi ₁ that has reached the goal, there is a relationship represented by the formula _{(30), ρ 1 = λ} 1 × (2n 1 π + φ 1) / 4π ...... (30) where, _{n 1} is , An integer. Same in the following equations.

[0006] In addition, radio waves radiated from the second SAR
Frequency is λ₂, And between the second SAR and the target
Distance ρ₂From the SAR image received by the second SAR
Phase φ of the radio wave reaching the target₂Between
There is a relation given by (31). ρ₂= Λ₂× (2n₂π + φ₂) / 4π (31) where n₂Is an integer. Same in the following equations. This
In these equations (30) and (31), λ₁= Λ₂= Λ
Then, in Expressions (30) and (31), n₁And n₂Between
Has n₁= N₂ (32) is established. Therefore, the aforementioned distance difference ρ₂−ρ₁And eyes
Phase difference φ of radio wave reaching the target₂−φ ₁Between ρ₂−ρ₁= Λ × (φ₂−φ₁) / 4π (33) is established. Assuming that equation (7) holds,
However, the above-mentioned conventional cross interferometry S
AR device and along interferometry SAR device
It is.

Therefore, the conventional cross-interfero
In a metrology SAR device, two SARs
Phase difference φ of the radio wave reaching the target from the SAR image₂−
φ₁ To calculate the elevation of the ground surface target,
Also, a conventional along interferometry SAR device
SAR image received by two SARs
Phase difference of the radio wave reaching the target₂−φ₁In search of
It is possible to calculate the moving speed of the target on the ground.

[0008]

However, the conventional cross-interferometry SAR device and the long-interferometry SAR device can be configured only when the radio waves radiated from the two SARs have the same frequency. When the frequency of the radio wave radiated from the two SARs is different, the interferometry SA
There is a problem that the R device cannot be configured.
Also, because you must use radio waves of the same wavelength,
There are restrictions on the choice of wavelength. There is also a disadvantage that the distance between each SAR and the target cannot be measured.

The present invention has been made in view of the above-described circumstances, and uses a radio wave of different wavelengths radiated from one SAR or a plurality of SARs of a flying object to determine the distance from the flying object to a target. It is an object of the present invention to provide an interferometric SAR method and apparatus capable of measuring a target altitude and a moving speed, and a recording medium on which an interferometric SAR program is recorded.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 radiates radio waves from a SAR to a target, receives radio waves reflected by the target by the SAR, and According to an interferometric SAR method of calculating a distance between a SAR and the target, a phase of a radio wave reaching the target is measured from the image of the target received by the SAR, and a phase of the target received by the SAR is measured. Generate a reception gate time for sampling pixels in the image from the image, the measured phase of the radio wave reaching the target, the generated reception gate time, the speed of the radio wave,
Based on the wavelength of the radio wave and slant range resolution,
The method is characterized in that a distance between the SAR and the target is calculated.

According to a second aspect of the present invention, the first and second SAs mounted on the flying object substantially at right angles to the traveling direction of the flying object.
R emits radio waves of different wavelengths toward a target on the ground, receives each of the radio waves reflected by the target at the first and second SARs, and obtains the target image received at each SAR from the target image The phase of the radio wave reaching the target is
The present invention relates to a method for measuring a target altitude in a cross-track interferometric SAR apparatus that calculates an altitude of the target including measuring each time, and samples pixels in the image from the target image received by the SAR. A reception gate time is generated for each of the SARs,
For each AR, the SAR and the target are determined based on the phase of the radio wave reaching the target measured by the SAR, the generated reception gate time, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution. And the calculated distance between the second SAR and the target, the calculated distance between the first SAR and the target,
Overlooking the target from the first SAR based on a horizontal distance difference between the first SAR and the second SAR and an altitude distance difference between the first SAR and the second SAR. Calculating a look-down angle, and calculating the target elevation based on the calculated look-down angle, the altitude of the first SAR, and the calculated distance between the first SAR and the target. Features.

[0012] The invention according to claim 3 relates to the interferometry SAR method according to claim 2, wherein the first SA is used.
Calculating the distance between the the R target satisfies the condition integer n ₁ is calculated, wherein the integer n ₁ issued the calculated formulas (3) and (5) in equation (1) (1) And assign it to
The calculation of the distance between the second SAR and the goal is to calculate a satisfying integer n ₂ in formula (4) and (6) in equation (2), the integer n ₂ issued the calculated The look-down angle is calculated by substituting into the equation (2), and the distance between the first SAR and the target calculated in the equation (7) and the calculated distance between the second SAR and the target are calculated. Distance, the first S
The target altitude is calculated by substituting the horizontal distance difference between the AR and the second SAR and the altitude distance difference between the first SAR and the second SAR. And the calculated looking down angle, the altitude of the first SAR, and the calculated distance between the first SAR and the target. _{ρ 1 = λ 1 × (2n} 1 π + φ 1) / 4π ...... (1) ρ 2 = λ 2 × (2n 2 π + φ 2) / 4π ...... (2) c × tRx1s / 2 <ρ 1 <c × tRx1s _{/ 2 + δρ 1 ...... (3} ) c × tRx2s / 2 <ρ 2 <c × tRx2s / 2 + δρ 2 ...... (4) δρ 1 <λ 1/2 ...... (5) δρ 2 <λ 2/2 ...... ( 6) ρ ₂ −ρ ₁ = B _y × COS θ−B _x × SIN θ (7) h = Y−ρ ₁ COS θ (8) where ρ ₁ is the difference between the first SAR and the target. Ρ ₂ is the distance between the second SAR and the target, λ ₁ is the wavelength of radio waves radiated from the first SAR toward the target, and λ ₂ is the second 2 SAR, the wavelength of the radio wave radiated toward the target, n ₁ and n ₂ are integers, and φ ₁ is the radio wave arriving at the target measured by the first SAR. The phase, φ _2, is the phase of the radio wave reaching the target measured by the second SAR, c is the speed of light, t
Rx1s is a reception gate time at which pixels in the target image received by the first SAR are sampled by the first SAR, and tRx2s is a pixel in the target image received by the second SAR. The second SAR
Reception gate time for sampling in, B _y, the first
Height difference between the SAR of the second SAR and the second SAR, B
_x is a horizontal distance difference between the first SAR and the second SAR, θ is a look-down angle looking down from the first SAR to the target, h is altitude of the target, and Y is the altitude of the target. 1 of SAR altitude, [Delta] [rho] _1, the slant range resolution of the first SAR, [Delta] [rho] ₂ is the slant range resolution of the second SAR.

According to a fourth aspect of the present invention, the first and second SAs mounted on the flying object substantially parallel to the traveling direction of the flying object.
R emits radio waves of different wavelengths toward a target on the ground, receives each of the radio waves reflected by the target at the first and second SARs, and obtains the target image received at each SAR from the target image The phase of the radio wave reaching the target is
A method for measuring a target moving speed in an along-track interferometry SAR device that calculates the moving speed of the target including measuring for each target, comprising: calculating a pixel in the image from the target image received by the SAR; A reception gate time for sampling is generated for each of the SARs, a time at which the target is captured by the first SAR is output, and a time at which the target is captured by the second SAR is output. Based on the phase of the radio wave reaching the target measured by the SAR, the generated reception gate time, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution, the SAR and the target are compared with each other. Calculating the distance between the first SAR and the time at which the target was captured by the first SAR and the time at which the target was captured by the second SAR, The distance between the between the issued second SAR target, the distance between the calculated first SAR and the target and on the basis of the time difference, is characterized by calculating a moving speed of the target.

According to a fifth aspect of the present invention, there is provided the interferometry SAR method according to the fourth aspect, wherein the first SA is used.
Calculating the distance between the the R target calculates a satisfying integer n ₁ in formula (11) and (13) in equation (9), the calculated out the integer n ₁ Equation (9) The distance between the second SAR and the target is calculated by calculating an integer n ₂ that satisfies the conditions of Expressions (12) and (14) in Expression (10). been integer n ₂ carried into equation (10), calculates the moving speed of the target, the distance between the said first SAR calculated for formula (15) target, which is calculated the first 2 is performed by substituting the distance between the SAR and the target and the calculated time difference. ρ ₁ = λ ₁ × (2n ₁ π + φ ₁ ) / 4π (9) ρ ₂ = λ ₂ × (2n ₂ π + φ ₂ ) / 4π (10) c × tRx1s / 2 <ρ ₁ <c × tRx1s _{/ 2 + δρ 1 ...... (11} ) c × tRx2s / 2 <ρ 2 <c × tRx2s / 2 + δρ 2 ...... (12) δρ 1 <λ 1/2 ...... (13) δρ 2 <λ 2/2 ...... ( 14) ρ ₂ −ρ ₁ = v × T (15) where v is the target moving speed, and T is the first S
The time difference between the time when the target was captured by the AR and the time when the target was captured by the second SAR, ρ ₁ is the distance between the first SAR and the target, and ρ ₂ is the second S
The distance between AR and the target, λ _1, is the first SA
Wavelength of radio waves radiated from R to the target, λ
₂ is the wavelength of a radio wave radiated from the second SAR toward the target, n ₁ and n ₂ are integers, φ ₁ is the first
Phase of radio waves reaching the target measured by the SAR of
phi _2, the second SAR in reaches the target measured electric wave phase, c is the speed of light, TRx1s, the said first pixel in the image of the target received by the SAR first SAR Reception gate time sampling at tRx
2s is the reception gate time for sampling pixels in the target image received by the second SAR with the second SAR, δρ ₁ is the slant range resolution of the first SAR, δρ ₂ is the This is the slant range resolution of the second SAR.

According to a sixth aspect of the present invention, the first and second SAs mounted on the flying object substantially at right angles to the traveling direction of the flying object.
R and a third SAR mounted substantially parallel to the traveling direction of the flying object together with one of the first SAR and the second SAR. Each of the radio waves reflected by the target is received by the first to third SARs, and the phase of the radio wave arriving at the target from the target image received by each SAR is determined for each of the SARs. The present invention relates to a method for measuring a target altitude and a moving speed in an interferometry SAR device that measures a target altitude and a moving speed including measuring, and samples pixels in the target image received by the SAR from the image. The reception gate time is set to each SAR
For each of the SARs, the time at which the target was captured by the first SAR is output, and the time at which the target was captured by the second SAR is output. The distance between the SAR and the target is calculated and calculated based on the phase of the radio wave reaching the target, the generated reception gate time, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution. Said second SAR
Distance between the first SAR and the target, the calculated distance between the first SAR and the target, the first SAR and the second SAR
The horizontal distance difference between the first SAR and the second SAR.
Of the first S
Calculating an overlooking angle overlooking the target from the AR, based on the calculated overlooking angle, the altitude of the first SAR, and the calculated distance between the first SAR and the target; Calculating the altitude, calculating the time difference between the time at which the target was captured by the first SAR and the time at which the target was captured by the second SAR, and
Distance between the target SAR and the target, and the calculated first S
A moving speed of the target is calculated based on a distance between the AR and the target and the time difference.

The invention according to claim 7 relates to the interferometry SAR method according to claim 6, wherein the first SA is used.
Calculating the distance between the the R target satisfies the condition integer _{n 1} is calculated, wherein the integer _{n 1} issued the calculated expression in (16) Equation (18) and (20) (16) The distance between the second SAR and the target is calculated by calculating an integer n ₂ that satisfies the conditions of Expressions (19) and (21) in Expression (17). been integer n ₂ carried into equation (17), calculation of the looking down angle,
The distance between the first SAR and the target calculated by equation (22), the calculated distance between the second SAR and the target, the horizontal direction between the first SAR and the second SAR The distance difference and the distance difference in the altitude direction between the first SAR and the second SAR are substituted, and the altitude of the target is calculated by using the calculated look-down angle and the first altitude in equation (23).
Is performed by substituting the altitude of the SAR and the calculated distance between the first SAR and the target, and calculating the moving speed of the target is based on the first SAR calculated by the equation (24). The method is characterized by substituting the distance to the target, the calculated distance between the second SAR and the target, and the calculated time difference. _{ρ 1 = λ 1 × (2n} 1 π + φ 1) / 4π ...... (16) ρ 2 = λ 2 × (2n 2 π + φ 2) / 4π ...... (17) c × tRx1s / 2 <ρ 1 <c × tRx1s _{/ 2 + δρ 1 ...... (18} ) c × tRx2s / 2 <ρ 2 <c × tRx2s / 2 + δρ 2 ...... (19) δρ 1 <λ 1/2 ...... (20) δρ 2 <λ 2/2 ...... ( 21) ρ ₂ −ρ ₁ = B _y × COS θ−B _x × SIN θ (22) h = Y−ρ ₁ COS θ (23) ρ ₂ −ρ ₁ = v × T (24) v is the target moving speed, and T is the first S
The time difference between the time when the target was captured by the AR and the time when the target was captured by the second SAR, ρ ₁ is the distance between the first SAR and the target, and ρ ₂ is the second S
The distance between AR and the target, λ _1, is the first SA
Wavelength of radio waves radiated from R to the target, λ
₂ is the wavelength of a radio wave radiated from the second SAR toward the target, n ₁ and n ₂ are integers, φ ₁ is the first
Phase of radio waves reaching the target measured by the SAR of
phi _2, the second SAR in reaches the target measured electric wave phase, c is the speed of light, TRx1s, the said first pixel in the image of the target received by the SAR first SAR Reception gate time sampling at tRx
2s is received gate time for sampling the second pixel in the image of the target received by SAR in the second SAR, B _y, the second S and the first SAR
Advanced direction distance difference between AR, _{B x,} the first SAR
Is a horizontal distance difference between the first SAR and the second SAR, θ is a look-down angle from the first SAR to the target, and h is
The target elevation, Y, is the altitude of the first SAR, δρ
₁ is the slant range resolution of the first SAR, δρ
₂ is the slant range resolution of the second SAR.

According to an eighth aspect of the present invention, radio waves of different wavelengths are emitted from a plurality of SARs mounted on the flying object toward a target on the ground at substantially right angles to the traveling direction of the flying object,
Receiving each of the radio waves reflected by the target at the corresponding SAR, and measuring the phase of the radio wave reaching the target for each of the SARs from the target image received at each of the SARs, According to a method of measuring a target altitude in a cross-track interferometry SAR apparatus for measuring altitude, a reception gate time for sampling pixels in the image from the target image received by the SAR is generated for each of the SARs. , For each SAR,
Based on the phase of the radio wave reaching the target measured in AR, the generated reception gate time, the speed of the radio wave and the wavelength of the radio wave, calculate the distance between the SAR and the target, The calculated distance between any one of the two SARs and the target in any two SARs of the plurality of SARs, the calculated distance in the two arbitrary SARs; The calculated distance between the other SAR of the two SARs and the target, the horizontal distance difference between the two SARs, and the two Ss
The plurality of SARs are determined based on a height direction distance difference between ARs.
A look-down angle overlooking the target is calculated from any one of the SARs; Is calculated based on the distance of the target.

According to a ninth aspect of the present invention, there is provided the interferometry SAR method according to the eighth aspect, wherein the calculation of the distance between the m SARs (m is an arbitrary natural number of 3 or more) and the target is performed by: In m equations (25 _m ), m equations (2
6 _m ), the integers n _{1 to} n _m satisfying the condition simultaneously
It is calculated and is characterized by calculating the calculated issued integer n ₁ to the integer n _m and the corresponding formula (25 _m) each SAR by substituting the distance between the target. ρ _m = λ _m × (2 _nm π + φ _m ) / 4π (25 _m ) c × tRxms / 2 <ρ _m <c × tRxms / 2 + δρ _m (26 _m ) where ρ _m is the above m the distance between the SAR and the target of, lambda _m is the wavelength of number of SAR of radio wave radiated toward the target m, n _m is an integer, the phi _m, are measured by the m-numbered SAR The phase of the radio wave reaching the target, c
Is the light speed, tRxms is the reception gate time for sampling pixels in the target image received by the m-th SAR with the m-th SAR, and δρ _m is the m-th S
This is the slantrene resolution of AR.

According to a tenth aspect of the present invention, the first and second S mounted on the flying object substantially at right angles to the traveling direction of the flying object.
The AR emits radio waves of different wavelengths toward a target on the ground surface, receives each of the radio waves reflected by the target at the first and second SARs, and obtains the target image received at each SAR from the image of the target. The phase of the radio wave reaching the target is
Cross-track interferometry SAR having phase measurement means for measuring each R to calculate the target elevation
Time generating means for generating, for each of the SARs, a reception gate time for sampling pixels in the image from the target image received by the SAR;
For each AR, based on the phase of the radio wave reaching the target measured by the SAR, the reception gate time generated by the time generation means, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution, Distance calculating means for calculating a distance between the SAR and the target; and a distance between the second SAR and the target calculated by the distance calculating means and the first SAR calculated by the distance calculating means. Difference between the distance between the first SAR and the second SAR
The horizontal distance difference between the first SAR and the second SAR.
Of the first S
Angle calculating means for calculating a look-down angle looking down on the target from AR, the calculated look-down angle, the first SA
An altitude calculating means for calculating a target altitude based on the altitude of R and the distance between the first SAR calculated by the distance calculating means and the target is provided.

According to the eleventh aspect of the present invention, the first and second S mounted on the flying object substantially parallel to the traveling direction of the flying object.
The AR emits radio waves of different wavelengths toward a target on the ground surface, receives each of the radio waves reflected by the target at the first and second SARs, and obtains the target image received at each SAR from the image of the target. The phase of the radio wave reaching the target is
Along track interferometry SA for calculating a target moving speed by having a phase measuring means for measuring each R
A time generation means for generating, for each of the SARs, a reception gate time for sampling pixels in the target image from the target image received by the SAR; Time output means for outputting the time at which the SAR was captured, the phase of the radio wave reaching the target measured by the SAR, the reception gate time generated by the time generation means, the speed of the radio wave for each of the SARs A distance calculating unit that calculates a distance between the SAR and the target based on a wavelength of the radio wave and a slant range resolution; and the first output unit that is output from the time output unit.
The time at which the target was captured by the SAR and the second SAR
A time difference calculating means for calculating a time difference from a time at which the target was captured, a distance between the second SAR calculated by the distance calculating means and the target, and a first distance calculated by the distance calculating means. Speed calculation means for calculating the moving speed of the target based on the distance between the SAR and the target and the time difference calculated by the time difference calculation means.

According to a twelfth aspect of the present invention, the first and second S mounted on the flying object substantially at right angles to the traveling direction of the flying object.
An AR and a third SAR mounted substantially in parallel with the traveling direction of the flying object together with one of the first and second SARs to direct radio waves having different wavelengths to a target on the ground. Each of the radio waves reflected by the target is received by the first to third SARs, and the phases of the radio waves reaching the target are measured by the SARs from the target image received by the SARs. According to the along track interferometry SAR apparatus having a phase measuring means for calculating the moving speed of the target, the reception gate time for sampling pixels in the image from the target image received by the SAR is set as the reception gate time. Time generating means for generating each SAR, time output means for outputting the time at which the target was captured by the first and second SARs, and time outputting means for each SAR; Based on the measured phase of the radio wave reaching the target, the reception gate time generated by the time generation means, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution, the distance between the SAR and the target is determined. Distance calculating means for calculating the distance between the second SAR and the target calculated by the distance calculating means, the distance between the first SAR and the target calculated by the distance calculating means, Overlooking the target from the first SAR based on a horizontal distance difference between the first SAR and the second SAR and an altitude distance difference between the first SAR and the second SAR. An angle calculating means for calculating a look-down angle;
The looking-down angle calculated by the angle calculating means, the first S
The altitude of the AR and the first value calculated by the distance calculating means.
Altitude calculating means for calculating an altitude of the target based on a distance between the SAR and the target, a time at which the target is captured by the first SAR output from the time output means, A time difference calculating means for calculating a time difference between the time when the target is captured by the SAR, a distance between the second SAR calculated by the distance calculating means and the target, and a distance calculated by the distance calculating means. And a speed calculating means for calculating a target moving speed based on a distance between the SAR and the target and a time difference calculated by the time difference calculating means.

According to a thirteenth aspect of the present invention, radio waves having different wavelengths are respectively emitted from a plurality of SARs mounted on the flying object toward a target on the ground at a substantially right angle to the traveling direction of the flying object, and reflected by the target. Each of the target radio waves received by each of the SARs, and from the target image received by each of the SARs, a phase measuring means for measuring, for each of the SARs, the phase of the radio wave that has reached the target. The present invention relates to a cross-track interferometry SAR device for measuring altitude,
A time generating means for generating, for each of the SARs, a reception gate time for sampling pixels in the image from the target image received by the AR;
The distance between the SAR and the target based on the phase of the radio wave reaching the target measured by R, the reception gate time generated by the time generation means, the speed of the radio wave, and the wavelength of the radio wave. Distance calculating means for calculating the two SARs for each two SARs of the plurality of SARs.
The calculated distance between any one of the SARs and the target, the two for each of the two SARs
Based on a difference between the calculated distance between the other SAR and the target, a horizontal distance difference between the two SARs, and an altitude distance difference between the two SARs. Angle calculation means for calculating a look-down angle looking down on the target from any one of the plurality of SARs; a look-down angle calculated by the angle calculation means; an altitude and a calculation of the one arbitrary SAR An altitude calculation means for calculating an altitude of the target based on a distance between the arbitrary one of the SARs and the target.

According to a fourteenth aspect of the present invention, there is provided a computer-readable recording medium storing an interferometric SAR program for causing a computer mounted on a flying object to calculate a target elevation on the ground. The first and second SAs for each of the first and second SARs mounted on the projectile substantially at right angles to the traveling direction of
R, the phase of the radio wave reaching the target, the reception gate time for sampling pixels in the image of the target received by the first and second SARs with the first and second SARs, the radio wave Based on the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution.
Calculating the distance between AR and the target;
A distance between an AR and the target, a distance between the first SAR and the target, a horizontal distance difference between the first SAR and the second SAR, and a difference between the first SAR and the second SAR
Based on the height direction distance difference between the first SAR and the first SAR, a look-down angle overlooking the target is calculated, and the look-down angle, the altitude of the first SAR, and An interferometry SAR program for calculating the target altitude based on the distance is recorded.

According to a fifteenth aspect of the present invention, there is provided a computer-readable recording medium storing an interferometry SAR program for causing a computer mounted on a flying object to calculate a target moving speed on the ground. For each of the first and second SARs mounted on the flying object substantially parallel to the direction of travel of the body, the phase of the radio wave reaching the target measured by the SAR, the reception gate time generated by the SAR, The distance between the target SAR and the target is calculated based on the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution, and the calculated distance between the second SAR and the target is calculated. The distance between the first SAR and the target and the difference between the time at which the target was captured at the first SAR and the time at which the target was captured at the second SAR; Based on, it is characterized by recording the interferometry SAR program for calculating a moving speed of the target.

According to a sixteenth aspect of the present invention, there is provided a computer-readable recording medium storing an interferometric SAR program for causing a computer mounted on a flying object to calculate a target elevation on the ground. For each of a plurality of SARs mounted on the flying object at a right angle to the traveling direction of the object, the phase of the radio wave reaching the target measured by the SAR, the reception gate time generated by the SAR, and the speed of the radio wave And calculating the distance between the target SAR and the target based on the wavelength of the radio wave, and selecting one of the two SARs for any two SARs of the plurality of SARs. The calculated distance between the SAR and the target, the two arbitrary SAs
The calculated distance between the other of the two SARs for each R and the target, the horizontal distance difference between the two SARs, and the altitude distance difference between the two SARs. Based on any one of the plurality of SARs, an overlook angle overlooking the target is calculated, and the calculated overlook angle, the one arbitrary SAR
And an interferometric SAR program for calculating the altitude of the target based on the calculated altitude and the calculated distance between the one arbitrary SAR and the target.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. The description will be specifically made using an embodiment. First Embodiment FIG. 1 is a cross-track diagram showing a first embodiment of the present invention.
FIG. 2 is a block diagram showing an electrical configuration of the interferometry SAR device, FIG. 2 is a flowchart showing an operation processing procedure executed by the SAR device, and FIG.
FIG. 4 is a diagram showing a geometric positional relationship between an AR and a target, and FIG.
FIG. 5 is an explanatory diagram for explaining a phase unwrapping process used for measurement of an AR device, and FIG. 5 is an explanatory diagram for explaining slant range resolution. The cross interferometry SAR device of this example is a cross interferometry SAR device that measures the elevation of a target on the ground surface with different wavelengths of radio waves radiated from two synthetic aperture radars (SARs). And the cross-interferometry SAR device 10 includes a first transmitter 12, a first antenna 14, a first receiver 16, a second transmitter 18, a second antenna 20, and a second receiver 2
2, and an SAR reproduction processing / interferometry processing device 24. The first transmitter 12 and the first receiver 16 are connected to a first antenna 14,
The second transmitter 18 and the second receiver 22 are connected to a second antenna 20. The first receiver 16 and the second
Is connected to the SAR reproduction processing / interferometry processing device 24.

The first transmitter 12, the first antenna 14,
The first receiver 16 and the SAR reproduction processing / interferometry processing device 24 constitute a first SAR 26, and include a second transmitter 18, a second antenna 20, a second receiver 22, and a SAR The reproduction processing / interferometry processing device 24 constitutes the second SAR 28. The SAR reproduction processing / interferometry processing device 2
4 may be provided for each SAR. The SAR reproduction processing / interferometry processing device 24 is configured to include a computer system, and the ROM of the computer system stores a program for executing the processing procedure shown in the flowchart shown in FIG. The program is read from the ROM by a computer constituting the computer system and executed by the computer, thereby performing the processing of the processing procedure shown in FIG. The slant range resolution used in the processing procedure shown in FIG. 2 is set to be smaller than half of the wavelengths λ ₁ and λ ₂ of the two radio waves radiated toward the target.

Next, the processing operation of this embodiment will be described with reference to FIGS. From the geometrical positional relationship between the first SAR 26 and the second SAR 28 and the target in the cross-track interferometry SAR device shown in FIG. 3, the relationship given by Expressions (60) and (61) is established. _{ρ 2 -ρ 1 = B y ×} COSθ-B x × SINθ ...... (60) h = Y-ρ 1 COSθ ...... (61) where, [rho ₁ is the distance between the first SAR26 and the target,
ρ ₂ is the distance between the second SAR 28 and the target, B
_y is the distance difference altitude direction between the first SAR26 and second SAR28, _{B x} is the first SAR26 second SAR
, The horizontal angle difference from the first SAR 26 to the target, h is the target elevation on the ground, Y
Is the altitude of the first SAR 26. Same in the following equations.

In the first and second SARs 26 and 28,
The phase of the radio wave reaching the target to be received, and the first and second
The distance between the SARs 26 and 28 and the target is expressed by the following equation.
The relationship given by (62) and (63) holds. ρ₁= Λ₁× (2n₁π + φ₁) / 4π (62) ρ₂= Λ₂× (2n₂π + φ₂) / 4π (63) where λ₁Radiates from the first SAR 26 towards the target
Wavelength of the radio wave ₂Is the target from the second SAR28
Wavelength of radio waves radiated toward₁And n₂Is an integer,
φ₁Has reached the target measured by the first SAR 26
Radio wave phase, φ ₂Is the eye measured by the second SAR 28
This is the phase of the radio wave that has reached the target.

The first and second SARs 26, 28
Slant range resolution δρ₁, Δρ ₂And the first and second
Between the SARs 26, 28 and the distance between the targets is
The relationship given by (64) and (65) holds. c × tRx1s / 2 <ρ₁<C × tRx1s / 2 + δρ₁(64) c × tRx2s / 2 <ρ₂<C × tRx2s / 2 + δρ₂(65) where c is the speed of light and tRx1s is the first SAR26.
Pixels in the target image obtained from the received image
(Area represented as one point on the SAR image)
Reception gate time for sampling (first SAR 26
After radiating radio waves toward the target, the radio waves return
TRx2s is tRx2s
Target image received by the second SAR 28, similar to 1s
Is the timing to sample the pixels in
Gate time.

[0031] As a condition for determining the _{n 1} and _{n 2} of the formula (62) and _{(63), δρ 1 <λ} 1/2 ...... (66) δρ 2 <λ 2/2 ...... is (67) , Cross-track interferometry SAR device. When the slant range resolution is smaller than 波長 of the wavelength, information in which the reciprocating distance is longer than the wavelength is not mixed in each pixel of the SAR image (FIG. 5A). When the resolution is larger than half the wavelength, information having a longer reciprocating distance than the wavelength is mixed in each pixel of the SAR image. The phase has a distance from 0 to 360 degrees corresponding to the wavelength as a distance. If information in which the reciprocating distance is longer than the wavelength is mixed in each pixel of the SAR image, 0 is set every time the distance becomes a multiple of the wavelength. From the degree, 360 degrees are repeated by a multiple of the wavelength (FIG. 5B).

Therefore, if the slant range resolution is larger than 1/2 of the wavelength, the position of the target in the pixel cannot be specified even if the phase is used, and the accurate distance to the target must be calculated. Can not be formed and a cross-track interferometry SAR device cannot be constructed, so that as a condition for determining n ₁ and n ₂ in the equations (62) and (63), the equations (66) and (67) are Given.

Using these relations (60) to (67), the target altitude h can be calculated as follows. TRx1s of phi ₁ of the formula (62) (64)
The first SAR 26 emits a radio wave of the wavelength λ ₁ toward the target, obtains from the target image reproduced from the radio wave reflected and returned by the target in the same manner as in the related art, and 6
TRx2s 3) of phi ₂ and equation (65), the second SA
R28 is toward the target radiates radio waves of lambda _2, the target of the image reproduced from the radio wave coming back after being reflected by the target, calculated in the same manner as in the conventional (step SA1 in FIG. 2). The phi ₁ and lambda ₁ into Equation (62), c, substituting tR1s and [Delta] [rho] ₁ in the formula (64), wherein the [Delta] [rho] ₁ and lambda ₁ (6
6), and in Expression (62), Expressions (64) and (6)
After calculating n ₁ that satisfies the condition of 6) from equation (62), ρ ₁ is calculated from equation (62) (step SA).
2). FIG. 4 illustrates the relationship between Expressions (64) and (66). Similarly, substituting φ ₂ and λ ₂ into equation (63) and substituting c, tR2s and δρ ₂ into equation (65),
After substituting δρ ₂ and λ ₂ into equation (67) and calculating n ₂ satisfying the conditions of equations (65) and (67) in equation (63) from equation (63), ρ _{2 is} calculated from equation (63). Is calculated (step SA3). Note that Equation (65) and Equation (6)
FIG. 4 illustrates the relationship 7). Then, from the calculated ρ ₁ and ρ ₂ and the known By from the arrangement of the two SARs 26 and 28,
And Bx into equation (60) to calculate θ, and calculate the calculated θ and the first SAR 26 obtained by a known measuring means.
Then, the altitude h of the target on the ground surface is calculated by substituting the altitude Y of the target into the equation (61) (step SA4).

Thus, according to the configuration of this embodiment,
Two S arranged in the direction orthogonal to the traveling direction of the aircraft etc.
Radio waves having different wavelengths are emitted from the ARs 26 and 28 toward the target, and the altitude of the target can be measured.

Second Embodiment Next, a second embodiment of the present invention will be described. FIG.
FIG. 1 is a diagram showing an electrical configuration of an along-track interferometry SAR device according to a second embodiment of the present invention;
FIG. 7 is a flowchart showing an operation processing procedure executed by the SAR device, FIG. 8 is a diagram showing a geometrical positional relationship between the SAR of the SAR device and a target, and FIG.
It is explanatory drawing used for description of the process of the unwrapping of the phase used for the measurement of an apparatus. The configuration of this embodiment is significantly different from that of the first embodiment described above in that two SARs are mounted on an aircraft or the like in a direction parallel to the traveling direction of the aircraft or the like to calculate the target moving speed on the ground. The point is to get it. The first SAR 26A and the second SAR 2
The electrical configuration of 8A is the same as the first SAR 26 and the second SAR 28 of the first embodiment. First SAR26A
The second SAR 28A is mounted on an aircraft or the like in a direction parallel to the traveling direction of the aircraft or the like, as described above.

The first SAR 26A and the second SA
The configuration of the SAR reproduction processing / interferometry processing device 24A constituting the R28A is the same as that of the SAR reproduction processing / interferometry processing device 24 of the first embodiment. The SAR reproduction processing / interferometry processing device 24A includes a computer system.
A program for executing the processing procedure shown in the flowchart of FIG. This program is configured to be read from the ROM by a computer constituting the computer system and executed by the computer, thereby performing the processing of the processing procedure shown in FIG.

Therefore, the along-track interferometry SAR device 10A of this embodiment includes the first SAR 26A, the second SAR 28A, and the SAR reproduction / interferometry processing device 24A. The slant range resolution used in the processing procedure shown in FIG. 7 is set to be smaller than half of the wavelengths λ ₁ and λ ₂ of the two radio waves radiated toward the target. Except for the points described above, the configuration of this embodiment is the same as that of the cross-track interferometry SAR device of the first embodiment, but the arrangement position is different. The same components as those in FIG. 1 are denoted by the distinguishing symbols A, and the description thereof will be processed.

Next, the processing operation of this embodiment will be described with reference to FIGS. The first in the along track interferometry SAR device shown in FIG.
From the geometrical positional relationship between the target SAR 26A and the second SAR 28A and the target, the relationship given by Expression (68) is established. ρ ₂ −ρ ₁ = v × T (68) where ρ ₁ is the distance between the first SAR 26A and the target, ρ ₂ is the distance between the second SAR 28A and the target,
v is the target moving speed (slant range direction component), T
Is the time difference between the time at which the target was observed at the first SAR 26A and the time at which the target was observed at the second SAR 28A.

Further, the first and second SARs 26A, 28
As in the first embodiment, between the phase of the radio wave reaching the target measured at A and the distance between the first and second SARs 26A and 28A and the target, the following equations (69) and (69) The relationship given in (70) holds. ρ ₁ = λ ₁ × (2n ₁ π + φ ₁ ) / 4π (69) ρ ₂ = λ ₂ × (2n ₂ π + φ ₂ ) / 4π (70) where λ ₁ is a target from the first SAR 26A. Is the wavelength of the radio wave radiated toward the target, λ ₂ is the wavelength of the radio wave radiated from the second SAR 28A toward the target, n ₁ and n ₂ are integers, and φ ₁ is measured by the first SAR 26A. radio wave phase that has reached the target, phi ₂ is the wave of the phase which has reached the target measured by the second SAR28A.

Also, the first and second SARs 26A, 28
The relationship given by the following equations (71) and (72) holds between the slant range resolutions δρ ₁ and δρ _{2 of A} and the distances between the first and second SARs 26A and 28A and the target. . c × tRx1s / 2 <ρ ₁ <c × tRx1s / 2 + δρ ₁ (71) c × tRx2s / 2 <ρ ₂ <c × tRx2s / 2 + δρ ₂ (72) where c is the light speed and tRx1s is First SAR26A
The reception gate time, tRx2s, for sampling the pixels in the target image received at
The reception gate time for sampling pixels in the target image received by the second SAR.

[0041] As a condition for determining the _{n 1} and _{n 2} of the formula (69) and _{(70), δρ 1 <λ} 1/2 ...... (73) δρ 2 <λ 2/2 ...... is (74) , Along-track interferometry SAR device. The reason for giving this condition is
This is the same as the embodiment. These relational expressions (68) to (7)
Using 4), the target moving speed v can be calculated as follows. Φ _{1 in} equation (69) and equation (71)
TRx1s of the first SAR 26A emits a radio wave of the wavelength λ ₁ toward the target, and is obtained in the same manner as the related art from the target image reproduced from the radio wave reflected and returned by the target,
Further, TR2s the target of the second SAR28A radiates a radio wave of a wavelength lambda ₂ to the target, which is reproduced from the radio wave coming back after being reflected by the target in (70) phi ₂ and formula (72) From the image, it is obtained in the same manner as in the prior art (step S in FIG. 7).
B1). Substituting φ ₁ and λ ₁ into equation (69), c, tR
1s and δρ ₁ are substituted into equation (71), and δρ ₁ and λ ₁
Into equation (73), and in equation (69), equation (71)
And (73) satisfying the condition _{n 1} after calculated from equation (69), to calculate the [rho ₁ from equation (69) (step SB
2). FIG. 9 illustrates the relationship between Expressions (71) and (73).

Similarly, substituting φ ₂ and λ ₂ into equation (70), substituting c, tR2s and δρ ₂ into equation (72), and substituting δρ ₂ and λ ₂ into equation (74) Equation (70)
In After calculating the satisfying _{n 2} of formula (72) and (74) from equation (70), to calculate the [rho ₂ from equation (70) (Step SB3). Note that Equation (72) and Equation (7)
FIG. 9 illustrates the relationship 4). Then, the calculated moving speed v of the target on the ground is calculated by substituting the calculated ρ ₁ and ρ ₂ and the time difference T observed by the first SAR 26A and the second SAR 28A into the equation (68) (step SB4).

Thus, according to the configuration of this embodiment,
Two SAs arranged in a direction parallel to the traveling direction of an aircraft etc.
Radio waves of different wavelengths are radiated from the Rs 26 and 28 toward the target, and the moving speed of the target can be measured.

Third Embodiment Next, a third embodiment of the present invention will be described. FIG.
FIG. 9 is a diagram showing a configuration of an interferometry SAR device according to a third embodiment of the present invention. The configuration of this embodiment is significantly different from that of the first embodiment described above in that two of the three SARs are arranged in a direction perpendicular to the traveling direction of an aircraft or the like, and the remaining one SAR is arranged. Is mounted on an aircraft or the like in a direction parallel to the traveling direction of the aircraft or the like together with one of the two SARs so that the target elevation and moving speed on the ground can be calculated. In FIG. 10, reference numerals 26 and 28 denote two SARs arranged in a direction orthogonal to the traveling direction of an aircraft or the like.
30 is disposed in a direction parallel to the traveling direction of the aircraft or the like 2
SARs. These first, second and third SARs
26, 28, 30 include the first and second SARs 26, 28
And the first and third SARs 26 and 30, respectively,
Alternatively, a common SAR reproduction processing / interferometry processing apparatus is provided although not shown in FIG. This SAR reproduction processing / interferometry processing device is referred to by reference numeral 24B.

The first and second SARs 26 and 28 correspond to the SARs 26 and 28 of the first embodiment, respectively, and the first and third SARs 26 and 30 correspond to the SARs 26A and 28A of the second embodiment, respectively. Corresponding. Therefore, the first
The configuration of the SARs 26 and 28 is the same as that of the first embodiment.
AR 26, 28, the first and third S
The configuration of the ARs 26 and 30 is the same as that of the SAR 26A of the second embodiment.
Since the configuration is the same as 28A, a detailed description thereof will be omitted. The SAR reproduction processing / interferometry processing device 24B includes a computer system. The ROM of the computer system stores a program for executing the same processing procedure as the processing procedure of the flowcharts shown in FIGS. It is remembered. These programs are read from a ROM by a computer constituting a computer system and executed by the computer, so that the processing of the processing procedure shown in FIGS. 2 and 7 is performed. Therefore, the along track interferometry SAR of this embodiment
The device 10C includes a first SAR 26, a second SAR 28,
It is configured to include a third SAR 30 and a SAR reproduction processing / interferometry processing device 24B. The slant range resolution used in FIGS. 2 and 7 is the wavelength λ _{1 of} the two radio waves radiated toward the target,
It is set to be smaller than half of λ _2.

Next, the operation processing procedure of this embodiment will be described with reference to the flowcharts of FIGS. 2 and 7 and FIG. Also in this embodiment, the relations of the equations (1) to (60) described in the first embodiment hold, and the second
Equations (68) to (74) described in the embodiment are satisfied.
Therefore, TRX of phi ₁ of the formula (62) (64)
1s is obtained in the same manner as in the related art from the target image reproduced from the radio wave having the wavelength λ ₁ emitted from the first SAR 26 toward the target and reflected from the target and returned.
TRx2s (63) of phi ₂ and equation (65) from the second SAR28 radiates a radio wave of a wavelength lambda ₂ to the target, the target image reproduced from radio waves coming back after being reflected by the target , In the same manner as in the prior art (step SA in FIG. 2).
1). Substituting the φ ₁ and λ ₁ into equation (62), c, t
Substituting R1s and δρ ₁ into equation (64), δρ ₁ and λ
₁ into Expression (66), and in Expression (62), Expression (6)
4) and (after calculating satisfying _{n 1} 66) from equation (62), to calculate the [rho ₁ from equation (62) (step SA2).

Similarly, substituting φ ₂ and λ ₂ into equation (63), substituting c, tR1s and δρ ₂ into equation (65), and substituting δρ ₂ and λ ₂ into equation (67) Equation (63)
In After calculating the satisfying _{n 2} of formula (65) and (67) from equation (63), to calculate the [rho ₂ from equation (63) (step SA3). Then, the calculated ρ ₁ and ρ
_{2. From} the arrangement positions of the first and second SARs 26 and 28 on an aircraft or the like, θ is calculated by substituting the known By and Bx into the equation (60), and is obtained by the calculated θ and the known measuring means. The altitude Y of the target on the ground is calculated by substituting the altitude Y of the first SAR 26 into the equation (61) (step SA4).

In parallel with the calculation of the altitude h of the target on the ground, the processing of calculating the moving speed of the target is performed. That is, the first SAR 26 emits a radio wave of the wavelength λ ₁ toward the target, and from the target image reproduced from the radio wave reflected back from the target and returned, φ _{1 of} Expression (69) and Expression (71) TR
x1s is obtained in the same manner as in the past, and the third SAR3
0 is the wavelength λ ₃ toward the target (however, equations (70) and (7)
In applying 2) and equation (74), λ ₂ is used. )
Of radio waves radiated from the target image reproduced from radio waves coming back after being reflected by the target, phi ₂ and formula (70) (72)
TRx2s is determined in the same manner as in the prior art (step SB1 in FIG. 7). Substituting φ ₁ and λ ₁ into equation (69), substituting c, tR1s and δρ ₁ into equation (71),
By substituting ρ ₁ and λ ₁ into Expression (73), n ₁ satisfying the conditions of Expressions (71) and (73) in Expression (69) is expressed by Expression (6).
After calculating from 9) to calculate the [rho ₁ from equation (69) (step SB2). Similarly, φ ₂ and λ ₂ are substituted into Expression (70), and c, tR2s, and δρ ₂ are expressed by Expression (7).
After substituting δρ ₂ and λ ₂ into equation (73) and calculating n ₂ satisfying the conditions of equations (72) and (74) in equation (70) from equation (70), calculating a [rho ₂ from (70) (step SB3). Then, the calculated ρ ₁ and ρ ₂ , the first SAR 24 and the third SAR 30
By substituting the time difference T observed by Equation (68) into Equation (68), the target moving speed v on the ground is calculated (Step SB4).

As described above, according to the configuration of this embodiment,
Two S arranged in the direction orthogonal to the traveling direction of the aircraft etc.
Radio waves of different wavelengths are emitted from the ARs 26 and 28 toward the target, and radio waves of different wavelengths are emitted toward the target from the two SARs 26 and 30 arranged in a direction parallel to the target altitude and the traveling direction of the aircraft or the like. Thus, the moving speed of the target can be simultaneously measured.

Fourth Embodiment FIG. 11 is a diagram showing a configuration of a cross-track interferometry SAR device according to a fourth embodiment of the present invention, and FIG. It is a flowchart shown. The configuration of this embodiment is significantly different from that of the first embodiment described above in that three or more SARs are arranged in a direction orthogonal to the traveling direction of an aircraft or the like,
The cross-track interferometry SAR device is configured so that the slant range resolution is not restricted by the wavelength. In FIG. 11, 32, 34, 36
Are SARs arranged in a direction orthogonal to the traveling direction of the aircraft or the like. Each of the SARs 32, 34, and 36 is provided with a SAR reproduction processing / interferometry processing apparatus, which is not shown in FIG. This SAR reproduction processing / interferometry processing device is referred to by reference numeral 24C. SAR32,3
4 and 36 are SAR2 shown in the first embodiment.
Since the configuration is the same as that of Nos. 4 and 26, detailed description thereof is omitted.

The SAR reproduction / interferometry processing device 24C includes a computer system, and the ROM of the computer system includes:
A program for executing the processing procedure of the flowchart shown in FIG. 10 is stored. These programs are executed by a computer that constitutes a computer system.
M is read from M and executed by the computer, thereby performing the processing of the processing procedure shown in FIG. Therefore, the along track interferometry SAR device 10B of this embodiment includes a first SAR 32, a second SAR 34, a third SAR 36, and a SAR reproduction / interferometry processor 24C.
Is configured.

Next, the processing operation of this example will be described with reference to FIGS. A first SAR 32, a second SAR 34, and a third SAR 36 in the cross-track interferometry SAR device shown in FIG.
Equations (75) through (7)
The relationship given in 7) holds. _{ρ 2 -ρ 1 = B y2 ×} COSθ-B x2 × SINθ ...... (75) ρ 3 -ρ 1 = B y3 × COSθ-B x3 × SINθ ...... (76) h = Y-ρ 1 COSθ ...... ( 77) where ρ ₁ is the distance between the first SAR 32 and the target,
ρ ₂ is the distance between the second SAR 34 and the target, ρ
₃ is the distance between the third SAR 36 and the target, B
_{y 2} is an advanced direction a distance difference between the first SAR32 and second _{SAR34, B x2} includes a first SAR32 second SA
Horizontal distance difference B _y3 and R34 are, first SAR3
The height direction difference between B2 and the third SAR 36, B _x2 ,
The horizontal distance difference between the first SAR 32 and the second SAR 36, θ is the angle at which the first SAR 24 looks down to the target, h is the target elevation on the ground, and Y is the first SAR 32
Of altitude. Same in the following equations.

The first, second and third SARs 32,
The phase of the radio wave reaching the target measured at 34, 36,
The first, second and third SARs 32, 34, 36 and the target
Given by the following equations (78) and (80)
The relationship obtained is established. ρ₁= Λ₁× (2n₁π + φ₁) / 4π (78) ρ₂= Λ₂× (2n₂π + φ₂) / 4π …… (79) ρ₃= Λ₃× (2n₃π + φ₃) / 4π (80) where λ₁Radiates from the first SAR32 towards the target
Wavelength of the radio wave ₂Is the target from the second SAR34
Wavelength of the radio wave radiated toward₃Is the third SAR
The wavelength of the radio wave radiated from 36 to the target, n₁, N
₂And n₃Is an integer, φ₁Is measured by the first SAR32
Phase of the radio wave reaching the target₂Is the second SAR
The phase of the radio wave reaching the target measured at 34, φ₃Is
The position of the radio wave reaching the target measured by the third SAR 36
Phase.

Also, the first, second and third SARs 32,
34, 36 slant range resolutions δρ ₁ , δ
ρ ₂ , δρ ₃ and the first, second and third SAR 3
The relationships given by the following equations (81) to (83) hold between the distances 2, 34, and 36 and the distance between the targets. c × tRx1s / 2 <ρ ₁ <c × tRx1s / 2 + δρ ₁ (81) c × tRx2s / 2 <ρ ₂ <c × tRx2s / 2 + δρ ₂ (82) c × tRx3s / 2 <ρ ₃ <c × tRx3s / 2 + δρ ₃ (83) where c is the speed of light, tRx1s is the reception gate time for sampling pixels in the target image received by the first SAR 32, and tRx2s is the second, similar to tRx1s. The reception gate time tRx3s for sampling the pixels in the target image received by the SAR34 of the SAR34 is tRx
Similar to 1 s, the reception gate time for sampling pixels in the target image received by the third SAR 36.

[0055] tRx of formula (78) phi ₁ and formula (81)
1s is obtained in the same manner as in the related art from the target image reproduced from the radio wave having the wavelength λ ₁ emitted from the first SAR 32 toward the target and reflected from the target and returned. phi ₂ and tRx2s of formula (82), the second SAR34
Radiates a radio wave of wavelength λ ₂ toward the target, obtains a target image reproduced from the radio wave reflected and returned by the target in the same manner as in the past, and calculates φ _{3 of} (80) and the expression ( 83)
Of tRx3s the third SAR36 radiates radio waves having a wavelength lambda ₃ to the target, the target image reproduced from radio waves coming back after being reflected by the target, calculated in the same manner as in the conventional (in FIG. 12 Step SC1). Substituting φ ₁ and λ ₁ into equation (78), substituting φ ₂ and λ ₂ into equation (79), substituting φ ₃ and λ ₃ into equation (80), and
The tR1s and [Delta] [rho] ₁ into Equation (81), c, tR2
Substituting s and δρ ₂ into equation (82), and substituting c, tR3s and δρ ₃ into equation (83), and using equations (78) through (8)
0), n ₁ , n ₂ , and n ₃ that simultaneously satisfy the conditions of Expressions (81) to (83) are calculated from Expressions (78) to (80), and then calculated from Expressions (78) to (80). ρ ₁ , ρ
₂ , ρ ₃ are calculated (step SC2).

Then, the calculated ρ _{1 to} ρ ₃ and the first to third SARs 32, 3 mounted on an aircraft or the like.
Known _{B y2} and _{B x2} from the arrangement position of 4,36, as well as _{B y 3} and _{B x3} calculates θ is substituted into equation (75) and (76), the calculated θ and known measuring means The altitude h of the target on the ground is calculated by substituting the obtained altitude Y of the first SAR 32 into the equation (77) (step SC).
3).

As described above, according to the configuration of this embodiment,
Three S units arranged in a direction perpendicular to the traveling direction of the aircraft etc.
Radio waves of different wavelengths are radiated from the ARs 32, 34 and 36 toward the target, and the target altitude is not restricted by the slant range range as in the first to third embodiments.
Can be calculated.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific structure of the present invention is not limited to these embodiments, and departs from the gist of the present invention. Even if there is a change in the design within the range not to be included, the present invention is included. For example, in the first to fourth embodiments, SA
Although an example has been described in which R is arranged in a direction perpendicular to or parallel to the traveling direction of the aircraft or the like, it may be arranged in a direction intersecting. In the fourth embodiment, four or more SARs may be used. Further, the fourth embodiment can be implemented in an along-track interferometry SAR device. Further, in the fourth embodiment, as in the third embodiment, a cross-track interferometry SAR device and an along-track interferometry SAR device can be simultaneously configured.

[0059]

As described above, according to the configuration of the present invention, the phase of the radio wave reaching the target, the reception gate time,
Since the unwrapping of the phase is performed using the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution,
The distance from the SAR mounted on the flying object to the target can be measured. Also, by using the distance measured in this manner, radio waves of different wavelengths are emitted to the target from the two SARs mounted on the flying object, and the target altitude on the ground surface and the moving speed thereof can be measured. In addition, since it is not necessary to use radio waves having the same wavelength, restrictions on wavelengths are relaxed. In addition, since the phase is unwrapped using the phase of the radio wave reaching the target, the reception gate time, the speed of the radio wave, and the wavelength of the radio wave, three or more SARs mounted on the flying object are used to unwrap the target. Radiates radio waves of different wavelengths to the target, and can measure the elevation of the target on the ground surface and its moving speed. In addition, since it is not necessary to use radio waves having the same wavelength, restrictions on wavelengths are relaxed.

[Brief description of the drawings]

FIG. 1 shows a cross track according to a first embodiment of the present invention;
FIG. 2 is a block diagram illustrating an electrical configuration of the interferometry SAR device.

FIG. 2 is a flowchart showing an operation processing procedure executed by the SAR device.

FIG. 3 is a diagram showing a geometrical positional relationship between an SAR of the SAR device and a target.

FIG. 4 is an explanatory diagram used for explaining a phase unwrapping process used for measurement of the SAR device.

FIG. 5 is an explanatory diagram for explaining slant range resolution.

FIG. 6 is a diagram showing an electrical configuration of an along-track interferometry SAR device according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing an operation processing procedure executed by the SAR device.

FIG. 8 is a diagram showing a geometrical positional relationship between an SAR of the SAR device and a target.

FIG. 9 is an explanatory diagram used for describing a phase unwrapping process used for measurement of the SAR device.

FIG. 10 is a diagram illustrating an electrical configuration of an along-track interferometry SAR device according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a configuration of a cross-track interferometry SAR device according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart showing an operation processing procedure executed by the SAR device.

[Explanation of symbols]

10, 10c Cross-track interferometric SAR device 10A Along-track interferometric SAR device 10B Interferometric SAR device 12 First transmitter (part of phase measuring means and time generating means) 14 First antenna ( Phase measurement unit, part of time generation unit) 16 First receiver (part of phase measurement unit, part of time generation unit) 18 Second transmitter (part of phase measurement unit, part of time generation unit) 20 Second (Part of phase measurement means and time generation means) 22 Second receiver (part of phase measurement means and time generation means) 24 SAR reproduction processing / interferometry processing apparatus (phase measurement means and time generation means) The rest, distance calculation means, angle calculation means, elevation calculation means, time difference calculation means,
Speed calculating means) 26 first SAR 28 second SAR 30 third SAR 12A first transmitter (part of phase measuring means and time generating means) 14A first antenna (phase measuring means and time generating means) 16A First receiver (part of phase measuring means, time generating means) 18A Second transmitter (part of phase measuring means, time generating means) 20A Second antenna (phase measuring means, 22A Second receiver (part of phase measuring means, part of time generating means) 24A SAR reproduction processing / interferometry processing device (remaining phase measuring means and time generating means, distance calculating means, Angle calculation means, elevation calculation means, time difference calculation means, speed calculation means) 24B SAR reproduction processing / interferometry processing apparatus (remaining phase measurement means and time generation means, distance calculation means, Angle calculation means, elevation calculation means, time difference calculation means, speed calculation means) 24C SAR reproduction processing / interferometry processing apparatus (remaining phase measurement means and time generation means, distance calculation means, angle calculation means, elevation calculation means, time difference Calculation means, speed calculation means) 26A first SAR 28A second SAR 32 first SAR 34 second SAR 36 third SAR

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01S ⁷ /00-7/42 G01S 13/00-13/95

Claims (16)

(57) [Claims] 1. A radio wave is emitted from a SAR toward a target,
The radio wave reflected by the target is received by the SAR and the SA
An interferometry SAR method for calculating a distance between R and the target, wherein a phase of a radio wave reaching the target is measured from the target image received by the SAR, and the target received by the SAR is measured. Generating a reception gate time for sampling pixels in the image from the image, and measuring the phase of the measured radio wave reaching the target, the generated reception gate time, the speed of the radio wave, the wavelength of the radio wave, and the slant. Based on the range resolution, the SAR
And calculating a distance between the target and the target. 2. Radio waves of different wavelengths are respectively emitted from a first and a second SAR mounted on the flying object to a target on the ground substantially at right angles to the traveling direction of the flying object, and the radio waves reflected by the target are emitted. Are received by the first and second SARs,
A target altitude in a cross-track interferometry SAR device for calculating the target altitude including measuring the phase of radio waves reaching the target for each of the SARs from the target image received by each SAR A measuring method, wherein a reception gate time for sampling pixels in the target image from the target image received by the SAR is set to each of the SAs.
Generated for each R, and for each SAR, the phase of the radio wave reaching the target measured by the SAR, the generated reception gate time, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution Calculating a distance between the target SAR and the target, a distance between the calculated second SAR and the target, a calculated distance between the first SAR and the target, A look-down angle overlooking the target from the first SAR, based on a horizontal distance difference between the first SAR and the second SAR and an altitude distance difference between the first SAR and the second SAR; Calculating the altitude of the target based on the calculated look-down angle, the altitude of the first SAR, and the calculated distance between the first SAR and the target. Interfero Bird SAR method 3. The distance between the first SAR and the target is calculated by calculating an integer n ₁ that satisfies the conditions of Expressions (3) and (5) in Expression (1). Integer n ₁
Was carried out by substituting the equation (1), the calculation of the distance between the second SAR and the goal is to satisfy the integer n ₂ in formula in formula (2) (4) and (6) calculated, performed by substituting the integer n ₂ issued the calculated in equation (2), the calculation of the looking down angle, the distance between the said first SAR calculated for formula (7) target, is calculated The distance between the second SAR and the target, the horizontal distance difference between the first SAR and the second SAR, and the altitude distance difference between the first SAR and the second SAR. The target elevation is calculated by substituting the calculated look-down angle into the equation (8).
Altitude of the first SAR and the calculated first SA
3. The interferometric SAR method according to claim 2, wherein the method is performed by substituting a distance between R and the target. _{ρ 1 = λ 1 × (2n} 1 π + φ 1) / 4π ...... (1) ρ 2 = λ 2 × (2n 2 π + φ 2) / 4π ...... (2) c × tRx1s / 2 <ρ 1 <c × tRx1s _{/ 2 + δρ 1 ...... (3} ) c × tRx2s / 2 <ρ 2 <c × tRx2s / 2 + δρ 2 ...... (4) δρ 1 <λ 1/2 ...... (5) δρ 2 <λ 2/2 ...... ( 6) ρ ₂ −ρ ₁ = B _y × COS θ−B _x × SIN θ (7) h = Y−ρ ₁ COS θ (8) where ρ ₁ is the difference between the first SAR and the target. Ρ ₂ is the distance between the second SAR and the target, λ ₁ is the wavelength of radio waves radiated from the first SAR toward the target, and λ ₂ is the second 2 SAR, the wavelength of the radio wave radiated toward the target, n ₁ and n ₂ are integers, and φ ₁ is the radio wave arriving at the target measured by the first SAR. The phase, φ _2, is the phase of the radio wave reaching the target measured by the second SAR, c is the speed of light, t
Rx1s is a reception gate time at which pixels in the target image received by the first SAR are sampled by the first SAR, and tRx2s is a pixel in the target image received by the second SAR. The second SAR
Reception gate time for sampling in, B _y, the first
Height difference between the SAR of the second SAR and the second SAR, B
_x is a horizontal distance difference between the first SAR and the second SAR, θ is a look-down angle looking down from the first SAR to the target, h is altitude of the target, and Y is the altitude of the target. 1 of SAR altitude, [Delta] [rho] _1, the slant range resolution of the first SAR, [Delta] [rho] ₂ is the slant range resolution of the second SAR. 4. A radio wave of different wavelengths is respectively emitted from a first and a second SAR mounted on the flying object to a target on the ground substantially in parallel with a traveling direction of the flying object, and the radio wave reflected by the target is emitted. Are received by the first and second SARs,
Along track for calculating a moving speed of the target including measuring a phase of a radio wave reaching the target for each of the SARs from the image of the target received by each SAR.
A method for measuring a moving speed of a target in an interferometry SAR apparatus, wherein a reception gate time for sampling pixels in the image from the target image received by the SAR is set to each of the SAs.
Generated for each R, output the time at which the target was captured by the first SAR, output the time at which the target was captured by the second SAR, and measured at each SAR by the SAR Calculating a distance between the SAR and the target based on a phase of the radio wave reaching the target, the generated reception gate time, a speed of the radio wave, a wavelength of the radio wave, and a slant range resolution; The time at which the target was captured by the first SAR and the second
Calculating the time difference between the target SAR and the time at which the target was captured, based on the calculated distance between the second SAR and the target, the calculated distance between the first SAR and the target, and the time difference. And calculating the target moving speed. 5. The calculation of the distance between the first SAR and the target is performed by using Equations (11) and (1) in Equation (9).
3) calculating a satisfying integer n ₁ in performs integer n ₁ issued the calculated and substituted into Equation (9), the calculation of the distance between said second SAR goals, the formula ( in 10) calculates a satisfying integer _{n 2} in formula (12) and (14), the integer _{n 2} issued the calculated are substituted into equation (10), calculates the movement speed of the target is, The distance is calculated by substituting the distance between the first SAR and the target calculated in equation (15), the calculated distance between the second SAR and the target, and the calculated time difference. 5. The interferometric SAR method according to claim 4, wherein: ρ ₁ = λ ₁ × (2n ₁ π + φ ₁ ) / 4π (9) ρ ₂ = λ ₂ × (2n ₂ π + φ ₂ ) / 4π (10) c × tRx1s / 2 <ρ ₁ <c × tRx1s _{/ 2 + δρ 1 ...... (11} ) c × tRx2s / 2 <ρ 2 <c × tRx2s / 2 + δρ 2 ...... (12) δρ 1 <λ 1/2 ...... (13) δρ 2 <λ 2/2 ...... ( 14) ρ ₂ −ρ ₁ = v × T (15) where v is the target moving speed, and T is the first S
The time difference between the time when the target was captured by the AR and the time when the target was captured by the second SAR, ρ ₁ is the distance between the first SAR and the target, and ρ ₂ is the second S
The distance between AR and the target, λ _1, is the first SA
Wavelength of radio waves radiated from R to the target, λ
₂ is the wavelength of a radio wave radiated from the second SAR toward the target, n ₁ and n ₂ are integers, φ ₁ is the first
Phase of radio waves reaching the target measured by the SAR of
phi _2, the second SAR in reaches the target measured electric wave phase, c is the speed of light, TRx1s, the said first pixel in the image of the target received by the SAR first SAR Reception gate time sampling at tRx
2s is the reception gate time for sampling pixels in the target image received by the second SAR with the second SAR, δρ ₁ is the slant range resolution of the first SAR, δρ ₂ is the This is the slant range resolution of the second SAR. 6. A first and second SAR mounted on the flying object at a substantially right angle to a traveling direction of the flying object, and the first and second SARs are mounted on the flying object.
A radio wave of a different wavelength is emitted toward a target on the surface of the earth from a third SAR mounted substantially in parallel with the traveling direction of the flying object together with one of the SARs, and reflected by the target. Receiving each of the radio waves with the first to third SARs and measuring the phase of the radio wave that has reached the target for each of the SARs from the target image received by each of the SARs; And a method for measuring a target altitude and a moving speed in an interferometric SAR apparatus for measuring a moving speed, wherein a receiving gate time for sampling pixels in the image from the target image received by the SAR is set to each of the SAs.
Generated for each R, output the time at which the target was captured by the first SAR, output the time at which the target was captured by the second SAR, and measured at each SAR by the SAR Calculating the distance between the SAR and the target based on the phase of the radio wave reaching the target, the generated reception gate time, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution; The calculated distance between the second SAR and the target, the calculated distance between the first SAR and the target,
Based on the horizontal distance difference between the SAR and the second SAR, and the altitude distance difference between the first SAR and the second SAR, a look-down angle at which the target is looked down from the first SAR. Calculating an altitude of the target based on the calculated look-down angle, an altitude of the first SAR, and a calculated distance between the first SAR and the target; SAR
Calculating the time difference between the time at which the target was captured by the second SAR and the time at which the target was captured by the second SAR, and the calculated distance between the second SAR and the target, and the calculated first SAR An interferometric SAR method, wherein a moving speed of the target is calculated based on a distance between the target and the target and the time difference. 7. The calculation of the distance between the first SAR and the target is performed by using Equations (18) and (2) in Equation (16).
Calculating a satisfying integer _{n 1} 0), the integer _{n 1} issued the calculated are substituted into equation (16), the second SAR
Calculating the distance between the target and calculates a satisfying integer _{n 2} in formula (19) and (21) in equation (17), an integer _{n 2} issued the calculated in equation (17) The look-down angle is calculated by substituting the distance between the first SAR and the target calculated in equation (22), the calculated distance between the second SAR and the target, Is performed by substituting the horizontal distance difference between the SAR and the second SAR and the altitude distance difference between the first SAR and the second SAR. ) Is substituted for the calculated looking-down angle, the elevation of the first SAR, and the calculated distance between the first SAR and the target. 24) the calculated distance between the first SAR and the target, and the calculated second SAR SAR and the distance between the target and interferometry SAR method of claim 6, wherein the performing by substituting the time difference the calculated. _{ρ 1 = λ 1 × (2n} 1 π + φ 1) / 4π ...... (16) ρ 2 = λ 2 × (2n 2 π + φ 2) / 4π ...... (17) c × tRx1s / 2 <ρ 1 <c × tRx1s _{/ 2 + δρ 1 ...... (18} ) c × tRx2s / 2 <ρ 2 <c × tRx2s / 2 + δρ 2 ...... (19) δρ 1 <λ 1/2 ...... (20) δρ 2 <λ 2/2 ...... ( 21) ρ ₂ −ρ ₁ = B _y × COS θ−B _x × SIN θ (22) h = Y−ρ ₁ COS θ (23) ρ ₂ −ρ ₁ = v × T (24) v is the target moving speed, and T is the first S
The time difference between the time when the target was captured by the AR and the time when the target was captured by the second SAR, ρ ₁ is the distance between the first SAR and the target, and ρ ₂ is the second S
The distance between AR and the target, λ _1, is the first SA
Wavelength of radio waves radiated from R to the target, λ
₂ is the wavelength of a radio wave radiated from the second SAR toward the target, n ₁ and n ₂ are integers, φ ₁ is the first
Phase of radio waves reaching the target measured by the SAR of
phi _2, the second SAR in reaches the target measured electric wave phase, c is the speed of light, TRx1s, the said first pixel in the image of the target received by the SAR first SAR Reception gate time sampling at tRx
2s is received gate time for sampling the second pixel in the image of the target received by SAR in the second SAR, B _y, the second S and the first SAR
Advanced direction distance difference between AR, _{B x,} the first SAR
Is a horizontal distance difference between the first SAR and the second SAR, θ is a look-down angle from the first SAR to the target, and h is
The target elevation, Y, is the altitude of the first SAR, δρ
₁ is the slant range resolution of the first SAR, δρ
₂ is the slant range resolution of the second SAR. 8. A plurality of SARs mounted on the flying object emit radio waves of different wavelengths toward a target on the ground surface at a substantially right angle to the traveling direction of the flying object, and correspond to each of the radio waves reflected by the target. Cross-track interferometry for measuring the elevation of the target including measuring the phase of the radio wave reaching the target for each of the SARs from the target image received by each SAR. SA
A method of measuring a target altitude in an R apparatus, wherein a reception gate time for sampling pixels in the target image from the target image received by the SAR is set to each of the SAs.
For each SAR, based on the phase of the radio wave reaching the target measured by the SAR, the generated reception gate time, the speed of the radio wave, and the wavelength of the radio wave, Calculating a distance between the SAR and the target; and calculating the distance between any one of the two SARs and the target for each two SARs of the plurality of SARs. Distance, any two SARs
The calculated distance between the other of the two SARs and the target, the horizontal distance difference between the two SARs, and the elevation distance difference between the two SARs Based on any one of the plurality of SARs
Calculating a look-down angle overlooking the target from the two SARs; An interferometric SAR method, wherein the elevation of the target is calculated. 9. m S (m is an arbitrary natural number of 3 or more) S
The calculation of the distance between the AR and the target is performed using m equations (25
Conditions of m equations in _m) (26 _m) is calculated integer _{n 1} to the integer _{n m} are satisfied simultaneously, substitutes the calculated issued integer _{n 1} to the integer _{n m} to the corresponding formula (25 _m) 9. The interferometric SAR method according to claim 8, wherein a distance between each of the SARs and the target is calculated by using the method. ρ _m = λ _m × (2 _nm π + φ _m ) / 4π (25 _m ) c × tRxms / 2 <ρ _m <c × tRxms / 2 + δρ _m (26 _m ) where ρ _m is the above m the distance between the SAR and the target of, lambda _m is the wavelength of number of SAR of radio wave radiated toward the target m, n _m is an integer, the phi _m, are measured by the m-numbered SAR The phase of the radio wave reaching the target, c
Is the light speed, tRxms is the reception gate time for sampling pixels in the target image received by the m-th SAR with the m-th SAR, and δρ _m is the m-th S
This is the slantrene resolution of AR. 10. A radio wave having different wavelengths respectively emitted from a first and a second SAR mounted on the flying object at a substantially right angle to a traveling direction of the flying object toward a target on the ground, and the radio wave reflected by the target Each of the SARs is received by the first and second SARs, and the phase measurement means for measuring the phase of radio waves reaching the target for each of the SARs from the target image received by the SARs, What is claimed is: 1. A cross-track interferometry SAR device for calculating a target altitude, wherein a reception gate time for sampling pixels in the target image from the target image received by the SAR is set to each of the SAs.
A time generation unit that generates each R, a phase of a radio wave reaching the target measured by the SAR, the reception gate time generated by the time generation unit, a speed of the radio wave, Distance calculating means for calculating a distance between the SAR and the target based on the wavelength of the radio wave and slant range resolution; and a distance between the second SAR and the target calculated by the distance calculating means; A difference between the distance between the first SAR and the target calculated by the distance calculation means, a difference in horizontal distance between the first SAR and the second SAR, and a difference between the first SAR and the second SAR. Angle calculating means for calculating a look-down angle from the first SAR over the target based on a difference in altitude distance from the SAR; hand In based and calculated the first SAR on the distance between the target cross-track interferometry SAR apparatus characterized in that a and altitude calculating means for calculating the altitude of the target. 11. A radio wave of different wavelengths is respectively emitted from a first and a second SAR mounted on the flying object to a target on the ground substantially in parallel with the traveling direction of the flying object, and the radio wave reflected by the target is emitted. Each of the SARs is received by the first and second SARs, and a phase measurement unit is provided for measuring the phase of radio waves reaching the target for each of the SARs from the target image received by the SARs. Along-track interferometry SAR apparatus for calculating the moving speed of the target image received by the SAR, the reception gate time for sampling pixels in the image from the target image,
Time generation means for generating each R; time output means for outputting the time at which the target was captured by the first and second SARs; and for each of the SARs, the target measured by the SAR was reached. Distance calculating means for calculating the distance between the SAR and the target based on the phase of the radio wave, the reception gate time generated by the time generating means, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution. Time difference calculating means for calculating a time difference between a time at which the target is captured by the first SAR output from the time output means and a time at which the target is captured by the second SAR; and the distance calculating means. The distance between the second SAR and the target calculated by
Along-track interferometry SAR apparatus, comprising: a speed calculating means for calculating a moving speed of the target based on a distance between the SAR and the target and a time difference calculated by the time difference calculating means. . 12. The flying object together with a first and a second SAR mounted on the flying object at a substantially right angle to a traveling direction of the flying object and one of the first and the second SARs. Radio waves of different wavelengths are radiated from a third SAR mounted substantially parallel to the traveling direction of the target toward a target on the ground, and each of the radio waves reflected by the target is transmitted to the first to third radio waves.
Along track, which has phase measuring means for measuring the phase of the radio wave reaching the target from the target image received by each SAR using the SAR, and calculating the moving speed of the target. Interferometry SAR
An apparatus for sampling a pixel in the target image from the target image received by the SAR with a gate time for each of the SAs.
Time generation means for generating each R; time output means for outputting the time at which the target was captured by the first and second SARs; and for each of the SARs, the target measured by the SAR was reached. Distance calculating means for calculating the distance between the SAR and the target based on the phase of the radio wave, the reception gate time generated by the time generating means, the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution. And a distance between the second SAR and the target calculated by the distance calculation means, a distance between the first SAR and the target calculated by the distance calculation means, and a distance between the first SAR and the target. 2 and a horizontal distance difference from the SAR of the first SAR
Angle calculating means for calculating a look-down angle at which the target is looked down on from the first SAR based on a distance difference between the first SAR and the second SAR; S
The altitude of the AR and the first value calculated by the distance calculating means.
Altitude calculating means for calculating an altitude of the target based on a distance between the SAR and the target, a time at which the target is captured by the first SAR output from the time output means, and a second A time difference calculating means for calculating a time difference between a time when the target is captured by the SAR, a distance between the second SAR calculated by the distance calculating means and the target, and a distance calculated by the distance calculating means. 1
An interferometry SAR apparatus, further comprising: a speed calculating unit that calculates a moving speed of the target based on a distance between the SAR and the target and a time difference calculated by the time difference calculating unit. 13. A plurality of SARs mounted on the flying object radiate radio waves of different wavelengths to a target on the ground at a substantially right angle to the traveling direction of the flying object, and each of the radio waves reflected by the target is transmitted to each of the SARs. A cross-track for receiving by another SAR and having a phase measuring means for measuring a phase of a radio wave reaching the target from the image of the target received by each SAR for each of the SARs and measuring an elevation of the target; An interferometry SAR device, wherein each SA is configured to sample a pixel in the image from the target image received by the SAR.
A time generating means for generating each R, a phase of a radio wave reaching the target measured by the SAR, a reception gate time generated by the time generating means, a speed of the radio wave, and A distance calculating means for calculating a distance between the SAR and the target based on a wavelength of the radio wave; and a distance calculating means for every two SARs of the plurality of SARs.
The calculated distance between any one of the two SARs and the target, and the calculated distance between the other SAR and the target of the two SARs for each of the two arbitrary SARs From any one of the plurality of SARs to the target, based on a difference from the determined distance, a horizontal distance difference between the two SARs, and an altitude distance difference between the two SARs. Angle calculation means for calculating a look-down angle looking down; and the look-down angle calculated by the angle calculation means;
Altitude of one SAR and the calculated any one SA
A cross-track interferometry SAR apparatus, comprising: altitude calculation means for calculating an altitude of the target based on a distance between R and the target. 14. An interferometry SA that causes a computer mounted on a flying object to calculate a target elevation on the ground.
A computer-readable recording medium on which an R program is recorded, the computer comprising: a first and a second SAR mounted on the flying object at a substantially right angle to a traveling direction of the flying object; 2, a phase of a radio wave reaching the target measured by the SAR of 2, a reception gate time for sampling pixels in the image of the target received by the first and second SARs by the first and second SARs, The first and second SARs are based on the speed of the radio wave, the wavelength of the radio wave, and the slant range resolution.
Calculating a distance between the second SAR and the target; calculating a distance between the second SAR and the target;
R based on the distance between the target and the target, the horizontal distance difference between the first SAR and the second SAR, and the altitude distance difference between the first SAR and the second SAR.
Calculating an overlooking angle overlooking the target from the SAR, and calculating an altitude of the target based on the overlooking angle, the altitude of the first SAR, and the distance between the first SAR and the target. A computer-readable recording medium on which a ferrometry SAR program is recorded. 15. A computer-readable recording medium recording an interferometry SAR program for causing a computer mounted on a flying object to calculate a moving speed of a target on the ground, wherein the computer has: For each of the first and second SARs mounted on the flying object substantially in parallel, the phase of the radio wave reaching the target measured by the SAR, the reception gate time generated by the SAR, the speed of the radio wave, The distance between the target SAR and the target is calculated based on the wavelength of the radio wave and the slant range resolution. The calculated distance between the second SAR and the target, the calculated first SAR The distance between the target and the target, the time at which the target was captured by the first SAR, and the second S
Interferometry SA for calculating the moving speed of the target based on the difference from the time at which the target was captured by AR
A computer-readable recording medium recording an R program. 16. An interferometry SA for causing a computer mounted on a flying object to calculate a target elevation on the ground.
A computer-readable recording medium on which an R program is recorded, the computer comprising, for each of a plurality of SARs mounted on the flying object substantially at right angles to the traveling direction of the flying object, the target measured by the SAR. Calculating a distance between the SAR and the target based on a phase of the arriving radio wave, a reception gate time generated by the SAR, a speed of the radio wave, and a wavelength of the radio wave; 2 for any two SARs of
The calculated distance between any one of the two SARs and the target, and the calculated distance between the other SAR and the target of the two SARs for each of the two arbitrary SARs Any one of the plurality of SARs based on the determined distance, the horizontal distance difference between the two SARs, and the altitude distance difference between the two SARs.
Calculating an overlooking angle overlooking the target from the AR, based on the calculated overlooking angle, the altitude of the one arbitrary SAR, and the calculated distance between the one arbitrary SAR and the target; A computer-readable recording medium on which an interferometric SAR program for calculating a target altitude is recorded.