CN103713286B - There is the high-resolution radio altimeter of positioning function and the method for measuring position - Google Patents

Abstract

The invention discloses a kind of high-resolution radio altimeter with positioning function, mainly solution present level table can only survey the problem that aircraft altitude can not be located.This height indicator comprises: three slave antennas, transmitter, three receivers, three analog-digital conversion a/ds, three storeies, distance treatment channel, distance processor, Phase Processing passage, phase processor and height and position processor; First slave antenna transmit-receive sharing, second, third pair is receiving antenna, and the Received signal strength of the second slave antenna obtains target oblique distance r successively after distance treatment channel, distance processor process; The Received signal strength of three width antennas obtains target interference angle θ successively after Phase Processing passage, phase processor process; The speed that height and position processor provides interference angle θ, oblique distance r and inertial navigation system and attitude information carry out data processing, obtain position coordinates (X, Y, Z) and the aircraft altitude H of target.The present invention can measure the height of aircraft and the position of ground return point simultaneously, can be used for assisting navigation.

Description

There is the high-resolution radio altimeter of positioning function and the method for measuring position

Technical field

The invention belongs to electronic instrument technology field, specifically a kind of radio altimeter, can be used for height and the position on the aircraft carrier distance ground such as survey aircraft.

Background technology

At present, aircraft needs navigator to provide the information such as orientation, speed, distance of aircraft in flight course, for self-position location and flight path correction, conventional navigational system has radar Doppler navigational system, inertial navigation system, satellite navigation system, images match navigational system etc., wherein images match navigational system utilizes Terrain Elevation sensor to mate with electronics elevation map to position, and the terrain feature below aircraft can also be provided to be used for forward direction crashproof and evade landform danger.Aircraft altitude needed for images match navigational system and the terrain feature below aircraft, the terrain feature that the aircraft altitude normally provided by radio altimeter is obtained in conjunction with airborne Interference synthetic aperture radar INSAR realizes independent navigation.

Radio altimeter carries on board the aircraft for the device of measuring height, and it is mainly used in the navigation of aircraft.Current radio altimeter adopts two antennas usually, an emitting antenna, a receiving antenna, this height indicator can only measure the height on the relative ground of aircraft, and its landform resolving power is determined by beam angle, fire pulse width or signal bandwidth, therefore landform resolving power is poor, and altimetry precision is not high, the terrain feature below aircraft cannot be obtained, can not position aircraft, by coordinating with carry-on miscellaneous equipment, conventional navigation can only be carried out.Such as, 265 radio altimeters that 782 factories produce, fire pulse width is 100ns, beam angle is ± 20 °, and at 1000m height, Terrain resolution is 173m × 173m, emissive power: 47dBm ~ 50dBm, secondary cun of profile: 190mm × 150mm × 96mm, weight 3.5kg are exactly the radio altimeter of this function.

Airborne Interference synthetic aperture radar INSAR can obtain the terrain feature below aircraft, and it utilizes two secondary receiving antennas, then carries out synthetic aperture imaging separately, then two sub-pictures are carried out the relief height that registration process can obtain full wafer landform.The volume of interference synthetic aperture radar is large, Heavy Weight, cost are high, and operand is large, method comparison is complicated, and these factors limit it and use on medium and small unmanned plane or guided missile.

Above-mentioned conventional height table landform resolving power is low, cannot position, and interference synthetic aperture radar is because cost is high, volume is not greatly suitable for installing and using of middle-size and small-size aircraft yet.

Summary of the invention

The object of the invention is to the deficiency for above-mentioned prior art, propose a kind of to there is the high-resolution radio altimeter of positioning function and the method for measuring position, with improve radio altimeter industrial resolution, reduce its volume and weight, reduce costs, make it meet medium and small unmanned plane and missile-borne request for utilization.

Technical scheme of the present invention is achieved in that

One, there is a high-resolution radio altimeter for positioning function, comprising: antenna, receiver, analog-digital conversion a/d, storer and signal processing unit, is characterized in that:

Antenna adopts three secondary, and namely the first slave antenna 1a is as duplexer, the second slave antenna 1b, the 3rd slave antenna 1c as receiving antenna, the corresponding receiver of every slave antenna;

Signal processing unit comprises: distance treatment channel 6, distance processor 8, Phase Processing passage 5, phase processor 7 and height and position processor 9;

Described distance treatment channel 6, becomes base band Doppler continuous wave signal for the echo signal of intermediate frequency received by the second slave antenna, and this base band Doppler continuous wave signal is exported to distance processor 8;

Described distance processor 8, the signal exported for treatment channel of adjusting the distance carries out level process successively, signal to noise ratio (S/N ratio) judges and range ambiguity resolving, obtains the oblique distance r of target, and this oblique distance is exported to height and position processor 9;

Described Phase Processing passage 5, for the echo signal of intermediate frequency received by three width antennas, becomes three roadbed band Doppler continuous wave signals respectively, and this three roadbeds band Doppler continuous wave signal is exported to phase processor 7;

Described phase processor 7, carries out phase-detection, Used for Unwrapping Phase Ambiguity successively for the signal exported Phase Processing passage, obtains the interference angle θ of target, and this interference angle is exported to height and position processor 9;

Described height and position processor 9, the target oblique distance r exported for the interference angle θ, the distance processor 8 that export phase processor 7 and the speed that provides of inertial navigation system 11 and attitude information carry out data processing, obtain position coordinates (X, Y, Z) and the aircraft altitude H of target.

Two, utilization has a method for positioning function high-resolution radio altimeter measuring position, comprises the steps:

1) launched earthward by the first slave antenna 1a after signal madulation pulse producer 13 produced;

2) echoed signal that three secondary receiving antennas receive separately is become intermediate-freuqncy signal after receiver process, give analog-digital conversion a/d module respectively carry out digitized sampling by three tunnel intermediate-freuqncy signals, Bing Jiang tri-tunnel sampled signal is given storer and is stored;

3) echo signal of intermediate frequency that the second slave antenna 1b in storer receives is exported to distance treatment channel 6 carries out being correlated with, correlation filtering, mixing and band filtering process become base band Doppler signal, and export to distance processor 8;

4) echo signal of intermediate frequency that three slave antennas in storer receive is exported to Phase Processing passage 5, the echo signal of intermediate frequency of every slave antenna is all correlated with, correlation filtering, mixing and band filtering process, become three roadbed band Doppler signals, and this three roadbeds band Doppler signal is exported to phase processor 7;

5) the base band Doppler signal of distance processor 8 to input carries out level detection successively, signal to noise ratio (S/N ratio) judges and range ambiguity resolving obtains target oblique distance r, and exports to height and position processor 9;

6) process of phase-detection, bilevel Linear programming is all carried out on phase processor 7 each road to three roadbed band Doppler signals, obtains the interference angle θ of target, and exports to height and position processor 9;

7) height and position processor 9 velocity (V that interference angle θ, the oblique distance r of input, inertial navigation system 10 are provided _x, V _y, V _z) and attitude information carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft:

Y＝rcosθ

$Z=(-b\±\sqrt{b^2-4\mathrm{ac}})/\left(2a\right)$

$X=\sqrt{{\left(r\sin \mathrm{\θ}\right)}^2-Z^2}$

H＝Z

In formula: $a=1+\frac{V_z^2}{4V_x^2},b=-A{V}_z\·\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos \mathrm{\β}},c=\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\β}\right)}^2}-{\left(r\sin \mathrm{\θ}\right)}^2,$

$A=\frac{{\left(V_{x}r\cos \mathrm{\β}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\β}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\β}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\θ}\right)}^2-{\left(r\sin \mathrm{\β}\right)}^2,$

the angle between oblique distance and aircraft speed, f _dfor Doppler frequency, λ is emission wavelength.

The present invention has the following advantages:

1, high-resolution radio altimeter of the present invention is by carrying out band division to horizontal and vertical, not only can measure the height of aircraft, the position of ground return point relative flight device can also be measured, if mated with digital elevation topomap by the terrain section line formed in tracking target process again, independent navigation can be completed.

2, resolution is high, operand is little, cost is low, lightweight, volume is little.

The terrain feature that the present invention utilizes Doppler and interference technique to come below explorer vehicle, carries out process to the signal of narrow Doppler's band and can realize high resolution; In baseband I/Q frequency mixer, sample process is carried out to data, substantially reduce operand; System composition is simple, and available dsp chip carries out high speed processing, reduces cost, weight and volume.

3, the present invention utilizes triantennary principle of interference bilevel Linear programming method simple, adopts triple channel to carry out range search simultaneously, improves search efficiency.

Accompanying drawing explanation

Fig. 1 is rang ring and Doppler's band schematic diagram of present level table echoed signal;

Fig. 2 is height indicator system chart of the present invention;

Fig. 3 is the reception echoed signal schematic diagram of three slave antennas in present system;

Fig. 4 is the composition frame chart of Phase Processing passage and distance treatment channel in present system;

Fig. 5 is orthogonal I/Q base band mixer block diagram in present system;

Fig. 6 is phase processor block diagram in present system;

Fig. 7 is present system middle distance processor block diagram;

Fig. 8 is the workflow diagram of present system middle distance processor;

Fig. 9 is the method flow diagram of height indicator measuring position in present system.

Embodiment

Embodiment of the present invention are further illustrated below by the drawings and specific embodiments.

As shown in Figure 1, the distance of the rang ring a relative flight device of existing height indicator echoed signal is r, and the frequency of Doppler's band b is 0, and the frequency of Doppler's band c is f1.When the present invention processes the ground echo received, the position of range gate is set to r, and band filter centre frequency is set to f1, just can obtain the echoed signal of target, carries out processing the position just uniquely can determining selected target to this signal.

With reference to Fig. 2, system of the present invention comprises: three secondary receiving antennas, three receivers, three A/D modules, three storeies, Phase Processing passage 5, distance treatment channel 6, phase processor 7, distance processor 8, height and position processor 9, inertial navigation system 10, clock oscillator 11, code generator 12, pulse producer 13, phase-modulator 14, transmit-receive switch 15 and distance controlling door 16;

Described three secondary receiving antennas are respectively the first slave antenna 1a, the second slave antenna 1a and the 3rd slave antenna 1c, three receivers are respectively the first receiver 2a, the second receiver 2b and the 3rd receiver 2c, three A/D modules are respectively an A/D module 3a, the 2nd A/D module 3b and the 3rd A/D module 3c, and three storeies are respectively first memory 4a, second memory 4b and the 3rd storer 4c;

Described first slave antenna 1a is as duplexer, the radiofrequency signal received is exported to the first receiver 2a by it, an A/D module 3a is exported to after radiofrequency signal is become intermediate-freuqncy signal by the first receiver 2a, one A/D module 3a is by the intermediate-freuqncy signal of input to export to first memory 4a after sample frequency 200MHz sampling, and first memory 4a exports to Phase Processing passage 5 after storing input signal; Second slave antenna 1b is as receiving antenna, the radiofrequency signal received is exported to the second receiver 2b by it, the 2nd A/D module 3b is exported to after radiofrequency signal is become intermediate-freuqncy signal by the second receiver 2b, 2nd A/D module 3b is by the intermediate-freuqncy signal of input to export to second memory 4b after sample frequency 200MHz sampling, and second memory 4b exports to Phase Processing passage 5 and distance treatment channel 6 respectively after storing input signal; 3rd slave antenna 1c is as receiving antenna, the radiofrequency signal received is exported to the 3rd receiver 2c by it, 3rd receiver 2c exports to the 3rd A/D module 3c after this radiofrequency signal is become intermediate-freuqncy signal, 3rd A/D module 3c is by the intermediate-freuqncy signal of input to export to the 3rd storer 4c after sample frequency 200MHz sampling, and the 3rd storer 4c exports to Phase Processing passage 5 after storing input signal respectively;

Described clock oscillator 11 produces an excitation and exports to yard generator 12, the Barker code signal producing 13 after excitation received by code generator 12 exports to phase-modulator 14, the pulse signal that pulse generator 13 produces also exports to phase-modulator 14, phase-modulator 14 exports to transmit-receive switch 15 by obtaining phase-coded signal after the symbol signal of input and pulse signal modulation, and input signal is launched through the first slave antenna 1a by transmit-receive switch 15 earthward;

Described Phase Processing passage 5, its echoed signal that three inputs are respectively first memory 4a, second memory 4b, the 3rd storer 4c exports, Phase Processing passage 5 becomes three roadbed band signals after being processed respectively by three road input signals, and this three roadbeds band signal is all exported to phase processor 7, phase processor 7 obtains the interference angle θ of target after being processed respectively by three road input signals, and this interference angle θ is exported to height and position processor 9;

Described distance treatment channel 6, its three inputs to be respectively in storer 4b three not echoed signals in the same time, distance passage 6 all exports to distance processor 8 to obtaining three roadbed band signals after three road input signal process respectively, the oblique distance r of target is obtained after distance processor 8 pairs of input signals process, and this oblique distance is exported to height and position processor 9, this oblique distance r is as the movement of FEEDBACK CONTROL distance controlling door 16 simultaneously;

Described height and position processor 9, speed, the attitude angle information of the aircraft target oblique distance r of input, interference angle θ, inertial navigation system 10 provided carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft.

With reference to Fig. 3, three secondary receiving antennas of height indicator of the present invention are positioned on straight line, and this straight line is vertical with the flight track of aircraft.When between any two slave antennas, spacing is larger, the target echo signal phase differential that they receive can produce phase ambiguity, the problem of above-mentioned phase ambiguity can be solved by this three slave antenna, and by the Long baselines between the first slave antenna 1a and the 3rd slave antenna 1c, accurate measurement is carried out to phase place.Phase processor 5 can obtain the interference angle θ of target after carrying out bilevel Linear programming process to three slave antenna echoes, height indicator system just can determine the position coordinates (X of target according to oblique distance r, the interference angle θ of target, speed and attitude angle information, Y, Z) and the height H of aircraft, target is the peak in selected Doppler's band.

With reference to Fig. 4, Phase Processing passage 5 of the present invention comprises: correlator 51, correlation filter 52, baseband I/Q frequency mixer 53 and bar band filter 54.

Correlator 51, the intermediate-freuqncy signal of input is carried out relevant to the local code signal that code generator 12 produces, and export to correlation filter 52, the pulse signal that correlator 51 exports by correlation filter 52 carries out the filtering of intermediate frequency band and becomes continuous wave signal, and exports to base band quadrature I/Q frequency mixer 53; Base band quadrature I/Q frequency mixer 53, the intermediate-freuqncy signal exported by correlation filter 52 carries out phase shift 90 °, mixing, low-pass filtering and data pick-up process successively, makes it become the baseband signal of positive frequency, and exports to bar band filter 54; Bar band filter 54, carries out band filtering by the baseband signal of the positive frequency of input, leaches the Doppler signal in selected Doppler's band, and suppresses the signal of other frequencies.

Middle distance treatment channel 6 structure of the present invention is identical with the structure of Phase Processing passage 5, and this two passage works simultaneously.

With reference to Fig. 5, baseband I of the present invention/Q frequency mixer 53 comprises: two frequency mixer, two low-pass filters, two withdrawal devices, two phase shifters and difference units 539; Described two frequency mixer are respectively the first frequency mixer 532 and the second frequency mixer 533, described two low-pass filters are respectively the first low-pass filter 534 and the second low-pass filter 535, described two withdrawal devices are respectively the first withdrawal device 536 and the second withdrawal device 537, and described two phase shifters are respectively the first phase shifter 531 and the second phase shifter 538.

First frequency mixer 532, the intermediate-freuqncy signal that intermediate-frequency filter 52 exports is become baseband signal, and export to the first low-pass filter 534, first low-pass filter 534 exports to the first withdrawal device 536 after the baseband signal of input is carried out low-pass filtering, input signal extracts by the first withdrawal device 536, and the signal after extracting is exported to difference unit 539;

The intermediate-freuqncy signal that intermediate-frequency filter 52 exports by the first phase shifter 531 exports to the second frequency mixer 533 after carrying out 90 ° of phase shifts, input intermediate-freuqncy signal is become baseband signal and exports to the second low-pass filter 535 by the second frequency mixer 533, second low-pass filter exports to the second withdrawal device 537 after input signal is carried out low-pass filtering, export to after input signal extracts by the second withdrawal device 537 second phase shifter 538, second phase shifter to input signal carry out 90 ° shift to after export to difference unit 539;

Difference unit 539 first withdrawal device 536 is outputed signal to output signal with the second phase-shifter 538 carry out difference after obtain the base band Doppler signal of positive frequency, and export to bar band filter 54.

With reference to Fig. 6, phase processor 7 of the present invention comprises: three phase detectors and Used for Unwrapping Phase Ambiguity unit 77, i.e. first phase detecting device 74, second phase detecting device 75 and third phase detecting device 76.

First phase detecting device 74, carries out phase compare by the echoed signal 71 of the first slave antenna of input and the echoed signal 72 of the second slave antenna, obtains the phase differential between two input signals, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit 77; Second phase detecting device 75, carries out phase compare by the echoed signal 72 of the second slave antenna of input and the echoed signal 73 of the 3rd slave antenna, obtains the phase differential between two input signals, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit 77; Third phase detecting device 76, carries out phase compare by the echoed signal 71 of the first slave antenna of input and the echoed signal 73 of the 3rd slave antenna, obtains the phase differential between two input signals, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit 77; Three phase differential that three phase detectors export are carried out bilevel Linear programming process, obtain the interference angle θ of target by Used for Unwrapping Phase Ambiguity unit 77.

With reference to Fig. 7, distance processor 8 of the present invention comprises: level processor 84, signal to noise ratio (S/N ratio) judge module 85 and distance processing unit 86; This distance processor is provided with three input signals, is respectively the first input signal 81, second input signal 82 and the 3rd input signal 83 of the output of distance treatment channel 6.

Level processor 84, first input signal 81, second input signal 82 and the 3rd input signal 83 are carried out signal power and the noise power that level process obtains three signals respectively, calculate the signal to noise ratio (S/N ratio) of three signals, and signal to noise ratio (S/N ratio) maximum in three is exported to signal to noise ratio (S/N ratio) judge module 85; Signal to noise ratio (S/N ratio) judge module 85, compares the signal to noise ratio (S/N ratio) of input and the signal-noise ratio threshold of setting, and comparative result is exported to distance processing unit 86, as an input of distance processing unit 86;

Distance processing unit 86, also have other three input signals, be respectively the first input signal 81, second input signal 82 and the 3rd input signal 83, distance processing unit 86 is to this first input signal 81, second input signal 82 and the 3rd input signal 83 find master, the range value of secondary lobe carries out being divided by and obtains principal subsidiary lobe ratio, and principal subsidiary lobe ratio maximum in three is carried out secondary thresholding with the principal subsidiary lobe ratio of setting compare, if be more all greater than setting thresholding for twice, think and capture target, namely the oblique distance r that range ambiguity resolving process obtains target is carried out to input signal, and this oblique distance is fed back to distance controlling door 16, target is followed the tracks of, if thresholding compares when there is being less than setting thresholds, then think and do not capture target, namely continue to search for target.

The principle of work of this distance processor 8 as described in Figure 8, that is:

(1) initialization is carried out to parameter, counter K=0 is set, ripple door moving step length τ ₀equal a chip lengths, search initial time is t ₀, duty is search, and signal-noise ratio threshold is Thr ₁, main-side lobe ratio thresholding is Thr ₂;

(2) produce three ripple doors by distance controlling door 16, i.e. early pulse, intermediate wave door, late pulse, make ripple door reference instant T=t ₀+ 3K τ ₀, when duty is for search, arranging early pulse initial time is T ₁=T-τ ₀, intermediate wave door initial time is T ₂=T, late pulse initial time is T ₃=T+ τ ₀; When duty is for following the tracks of, arranging early pulse initial time is T ₁=T-τ ₀2, intermediate wave door initial time is T ₂=T, late pulse initial time T ₃=T+ τ ₀the length of/2, three ripple doors is pulse width;

(3) three ripple doors are chosen the second slave antenna echo, and the three tunnel echoed signals chosen all are carried out the signal to noise ratio (S/N ratio) that level process obtains three signals, maximum snr value and signal-noise ratio threshold in three signals are compared; If signal to noise ratio (S/N ratio) is less than thresholding Thr ₁, then counter K=K+1 is set, performs step (2) and search for, if signal to noise ratio (S/N ratio) is greater than thresholding Thr next time ₁then perform step (4);

(4) the principal subsidiary lobe ratio of the echoed signal chosen by three ripple doors carries out second time thresholding and judges, if principal subsidiary lobe ratio maximum in three signals is less than setting thresholding Thr ₂, then think and do not capture target, counter K=K+1 is set, perform step (2) and search for next time; If maximum principal subsidiary lobe ratio is greater than setting thresholding Thr ₂, then think and capture target, range ambiguity resolving is carried out to the signal of three Bo Mennei and obtains target oblique distance r, perform step (5);

(5) duty is become tracking from search, and K=K+ (2r/C-T is set ₂)/(3 τ ₀), C is the light velocity, then repeats the distance tracking that step (2) carries out next cycle.

With reference to Fig. 9, by the method for present system measurement target position, comprise the steps:

Step 1, by first slave antenna 1a is earthward launched after the signal madulation produce by pulse producer 13;

Step 2, becomes intermediate-freuqncy signal by the echoed signal that three secondary receiving antennas receive separately after receiver process, gives analog-digital conversion a/d module respectively carry out digitized sampling by three tunnel intermediate-freuqncy signals, and Bing Jiang tri-tunnel sampled signal is given storer respectively and stored;

Step 3, exports to the echo signal of intermediate frequency that the second slave antenna 1b receives that distance treatment channel 6 carries out being correlated with, correlation filtering, mixing and band filtering process becomes base band Doppler signal, and export to distance processor 8;

Step 4, the echo signal of intermediate frequency that three slave antennas receive is exported to Phase Processing passage 5, the echo signal of intermediate frequency of every slave antenna is all correlated with, correlation filtering, mixing and band filtering process, become three roadbed band Doppler signals, and this three roadbeds band Doppler signal is exported to phase processor 7;

Step 5, the base band Doppler signal of distance processor 8 to input carries out level detection successively, signal to noise ratio (S/N ratio) judges and range ambiguity resolving obtains target oblique distance r, and exports to height and position processor 9.

Step 6, the process of phase-detection, bilevel Linear programming is all carried out on phase processor 7 each road to three roadbed band Doppler signals, obtains the interference angle θ of target, and exports to height and position processor 9;

Step 7, the velocity (V that the oblique distance r that the interference angle θ that step 6 exports by height and position processor 9, step 5 export, inertial navigation system 10 provide _x, V _y, V _z) and attitude information carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft.

(7a) by target oblique distance r and interference angle θ, target ordinate Y is obtained:

Y＝rcosθ；<1>

(7b) by target oblique distance r and interference angle θ, the interference equation of a circle obtaining target is:

X ²+Z ²＝(rsinθ) ²；<2>

(7c) by target oblique distance r and velocity (Vx, V _y, Vz), obtaining target Doppler equation of a circle is:

${(X-\frac{V_{x}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+{(Z-\frac{V_{z}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2={\left(r\sin \mathrm{\&beta;}\right)}^2,---<3>$

In formula be the angle between oblique distance and aircraft speed, fd is Doppler frequency, and λ is emission wavelength;

(7d) solving an equation interfering the middle Doppler equation of equation of a circle and step (7c) to be combined in the ordinate Y in step (7a), step (7b), obtaining the vertical coordinate Z of target and the horizontal ordinate X of target:

Formula <1> and formula <2> is substituted into formula <3>, and arranges:

$2\frac{V_{x}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}}X+2\frac{V_{z}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}}Z=\frac{{\left(V_{x}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\&theta;}\right)}^2-{\left(r\sin \right)}^2---<4>$

Order $A=\frac{{\left(V_{x}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\&theta;}\right)}^2-{\left(r\sin \mathrm{\&beta;}\right)}^2,$

Become after formula <4> is arranged:

$2\frac{V_{x}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+{V_y}^2+{y_z}^2}}X+2\frac{V_{z}r\cos \mathrm{\&beta;}}{\sqrt{{V_x}^2+{V_y}^2+{V_z}^2}}Z=A---<5>$

$X=\frac{A\sqrt{V_x^2+V_y^2+V_z^2}}{2V_{x}r\cos \mathrm{\&beta;}}-\frac{V_{z}Z}{2V_x};---\left(6\right)$

The horizontal ordinate X of target in formula <6> is substituted into formula <2> can obtain:

${(\frac{A\sqrt{V_x^2+V_y^2+V_z^2}}{2V_{x}r\cos \mathrm{\&beta;}}-\frac{V_{z}Z}{2V_x})}^2+Z^2={\left(r\sin \mathrm{\&theta;}\right)}^2,---<7>$

Formula <7> is arranged and obtains:

$(1+\frac{V_z^2}{4V_x^2})Z^2-{\mathrm{AV}}_z\&CenterDot;\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos }Z+\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\&beta;}\right)}^2}-{\left(r\sin \mathrm{\&theta;}\right)}^2=0---<8>$

Order $a=1+\frac{V_z^2}{4V_x^2},b=-{\mathrm{AV}}_2\&CenterDot;\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos \mathrm{\&beta;}},c=\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\&beta;}\right)}^2}-{\left(r\sin \mathrm{\&theta;}\right)}^2,$

Formula <8> is arranged and obtains:

aZ ²+bZ+c＝0<9>

Solution formula <9> can obtain the vertical coordinate Z of target:

$Z=(-b\&PlusMinus;\sqrt{b^2-4\mathrm{ac}})/\left(2a\right);---<10>$

The vertical coordinate Z of formula <10> target is substituted into formula <2>, the horizontal ordinate X of target can be obtained:

(7e) height H of aircraft is:

H＝Z。<12>。

Claims (1)

1. utilization has a method for the high-resolution radio altimeter measuring position of positioning function, comprises the steps:

1) launched earthward by the first slave antenna (1a) after signal madulation pulse producer (13) produced;

2) echoed signal that three secondary receiving antennas receive separately is become intermediate-freuqncy signal after receiver process, give analog-digital conversion a/d module respectively carry out digitized sampling by three tunnel intermediate-freuqncy signals, Bing Jiang tri-tunnel sampled signal is given storer and is stored;

3) echo signal of intermediate frequency that the second slave antenna (1b) in storer receives is exported to distance treatment channel (6) carries out being correlated with, correlation filtering, mixing and band filtering process become base band Doppler signal, and export to distance processor (8);

4) echo signal of intermediate frequency that three slave antennas in storer receive is exported to Phase Processing passage (5), the echo signal of intermediate frequency of every slave antenna is all correlated with, correlation filtering, mixing and band filtering process, become three roadbed band Doppler signals, and this three roadbeds band Doppler signal is exported to phase processor (7);

5) the base band Doppler signal of distance processor (8) to input carries out level detection successively, signal to noise ratio (S/N ratio) judges and range ambiguity resolving obtains target oblique distance r, and exports to height and position processor (9);

6) process of phase-detection, bilevel Linear programming is all carried out on phase processor (7) each road to three roadbed band Doppler signals, obtains the interference angle θ of target, and exports to height and position processor (9);

7) height and position processor (9) velocity (V that interference angle θ, the oblique distance r of input, inertial navigation system are provided _x, V _y, V _z) and attitude information carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft:

Y＝rcosθ

$Z=(-b\&PlusMinus;\sqrt{b^2-4ac})/\left(2a\right)$

$X=\sqrt{{\left(rsin\mathrm{\&theta;}\right)}^2-Z^2}$

H＝Z

In formula: $a=1+\frac{V_z^2}{4V_x^2},b=-{\mathrm{AV}}_z.\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}rcos\mathrm{\&beta;}},c=\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\&beta;}\right)}^2}-{\left(rsin\mathrm{\&theta;}\right)}^2,$

$A=\frac{{\left(V_{x}rcos\mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}rcos\mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}rcos\mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\&theta;}\right)}^2-{\left(rsin\mathrm{\&beta;}\right)}^2,$

the angle between oblique distance and aircraft speed, f _dfor Doppler frequency, λ is emission wavelength.