CN1940594A - Reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar - Google Patents

Abstract

A 3D rebuilding method of airborne interference synthetic aperture radar in non-right side view mode includes plotting out sketch map, defining physical meaning in sketch map, applying distance relation to set up the first relation chain, applying phase relation to set up the second relation chain, applying Doppler frequency relation to set up the third relation chain, defining coordinate system of orthogonal base, selecting said coordinate system and realizing 3D rebuilding according to obtained signal vector of based on said distance relation.

Description

A kind of reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method

Technical field

The information of the present invention relates to is obtained and processing technology field, particularly a kind of reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method.

Background technology

Interference synthetic aperture radar (SAR) technology is on traditional SAR remote sensing technology basis, in conjunction with differential GPS and inertia measurement technology and the new spatial remote sensing technology that grows up has round-the-clock, the round-the-clock characteristics of obtaining the digital elevation image.The interference SAR technology is measured traditional SAR and is extended to three dimensions from high-resolution object image two-dimensionally, is considered to the unprecedented earth observation from space technology that has potentiality.

The west area of China has wide area, and wherein major part belongs to traditional aerophotogrammetric area in hardship.Comprise the Qinghai-Tibet topographic mapping more than 5000m above sea level, the southwest is because the influence that cloud layer covers causes the mapping of no figure or few map-area, boundary line mapping etc.In these areas in hardship because the influence of factors such as geographical environment, weather, the drafting of the topomap that the traditional photography measuring method is difficult to realize that these are regional all the time.Certain areas can't obtain 1: 50000 or more large-scale topomap that satisfies certain accuracy requirement, and certain areas are basic or even do not have a map-area.Airborne interference SAR is owing to have round-the-clock, the round-the-clock characteristics of obtaining large tracts of land high accuracy number elevation map picture, and, thereby can solve 1: 50000 engineer's scale or more large-scale ground mapping of the area in hardship that traditional photography measures with certain side-looking incident angle earth observation.Therefore, develop the national task that the polarization sensitive synthetic aperture radar system with interference imaging function can be used for finishing 1: 50000 topomap surveying and drawing western about 500,000 square kilometres of territories, have profound significance.

Summary of the invention

The airborne Interference synthetic aperture radar three-dimensional rebuilding method is one of airborne Interference synthetic aperture radar core technology.The present invention's " a kind of reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method " has novelty and novelty, can satisfy the airborne Interference synthetic aperture radar three-dimensional reconstruction under the general flight condition.

Wherein, the airborne Interference synthetic aperture radar three-dimensional rebuilding method is one of core technology of airborne Interference synthetic aperture radar." a kind of reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method " that we propose has novelty and novelty, can satisfy the airborne Interference synthetic aperture radar three-dimensional reconstruction under the general flight condition.

Conventional airborne Interference synthetic aperture radar three-dimensional rebuilding method, its model is simple, realizes being merely able to satisfy the sided view on-board interfere synthetic bore radar three-dimensional reconstruction easily.And the airborne Interference synthetic aperture radar three-dimensional rebuilding method of our invention has generality, and model is complicated, can satisfy the reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar needs.

Content core of the present invention, the firstth, provided the spherical wave model of phase place; The secondth, the ingenious orthogonal basis coordinate system that defined; The 3rd is to have provided the airborne Interference synthetic aperture radar three-dimensional rebuilding method.

Description of drawings

Fig. 1 is a reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method flow diagram of the present invention.

Fig. 2 is an airborne Interference synthetic aperture radar three-dimensional rebuilding method vector correlation synoptic diagram.

Embodiment

The reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method of Fig. 1, step is as follows:

The first step is drawn synoptic diagram;

Second step, the physical significance in the definition synoptic diagram;

In radar interference is measured, two slave antennas must be arranged, therefore, establish vector

Be the position of antenna 1, vector

Be baseline, i.e. the connecting line of two antennas, vector

And vector Be respectively the distance of echo, then vector to antenna 1 and antenna 2

Being the three-dimensional position that will obtain, is the problem that will solve;

The 3rd step, catch distance relation, to set up first and close tethers, the radar return that returns from ground must be to satisfy equidistant relation, this is a sphere relation, i.e. AD=AB+BD=AB+|BD|A, wherein, vector

Be vector

Unit vector, be called and look vector;

The 4th step, catch phase relation, set up second and close tethers, in the radar video that two width of cloth antennas obtain, include phase information, the phase differential of two images of two width of cloth antenna correspondences satisfies certain relation, promptly satisfies hyperbolic relation;

$\mathrm{\Φ}=\frac{2\mathrm{\π}\left|\stackrel{\→}{\mathrm{BD}}\right|}{\mathrm{\λ}}[\sqrt{1-\frac{2\stackrel{\→}{\mathrm{BD}}\·\stackrel{\→}{\mathrm{BC}}}{{\left|\stackrel{\→}{\mathrm{BD}}\right|}^2}+{\left(\frac{\stackrel{\→}{\mathrm{BC}}}{\stackrel{\→}{\mathrm{BD}}}\right)}^2}-1]$

The 5th step, catch doppler frequency relation, set up the 3rd and close tethers, radar return includes phase information, along with the orientation to distribution, have frequency change, i.e. doppler frequency, multispectral rein in the speed that implied in the centre frequency an amount of with the relation of looking vector, promptly $f_d=\frac{2}{\mathrm{\λ}}\stackrel{\→}{A}\·\stackrel{\→}{V},$ This is a tapered relation;

The 6th step, the coordinate system of definition orthogonal basis, this is a most crucial step of the present invention, in the above-mentioned physical relation formula, the antenna of radar changes in time and moves.Therefore, look vector and change in time and change, the correct suitable coordinate system of ingenious selection is crucial, and the connecting line vector that we choose two antennas is first base, promptly $\stackrel{\→}{n_b=\frac{\stackrel{\→}{B}C}{\left|\stackrel{\→}{\mathrm{BC}}\right|}},$ Second base is positioned at velocity plane, promptly ${\stackrel{\→}{n}}_c=\frac{\stackrel{\→}{V}-(\stackrel{\→}{V}\·{\stackrel{\→}{n}}_b){\stackrel{\→}{n}}_b}{|\stackrel{\→}{V}-(\stackrel{\→}{V}\·{\stackrel{\→}{n}}_b){\stackrel{\→}{n}}_b|},$ The 3rd base satisfies right-hand rule, promptly ${\stackrel{\→}{n}}_d={\stackrel{\→}{n}}_c\×{\stackrel{\→}{n}}_b;$

In the 7th step,, make the sight line vector because the ingenious of above-mentioned orthogonal basis coordinate system choose

Problem solve and to become very direct, definition $\mathrm{BD}=\left|\mathrm{BD}\right|(a_1{n}_b+a_2{n}_c+a_3{n}_d),$ According to second phase relation formula, can get a ₁According to the 3rd doppler frequency relational expression, can get a ₂According to orthogonality, can get a ₃

The 8th step is by first distance relation, according to the sight line vector that obtains

Can realize three-dimensional reconstruction.

Fig. 2 is an airborne Interference synthetic aperture radar three-dimensional rebuilding method vector correlation synoptic diagram.Wherein, A is a true origin, i.e. the O of coordinate point.B, C are two antennas, i.e. antenna 1 and antenna 2.D is the position of any point of being asked.Promptly realize the some position of three-dimensional reconstruction.V is a speed.

Claims (1)

1. reconstruction for three-dimensional non-sided view on-board interfere synthetic bore radar method, its step is as follows:

The first step is drawn synoptic diagram;

Second step, the physical significance in the definition synoptic diagram;

In radar interference is measured, two slave antennas must be arranged, therefore, establish vector

Be the position of antenna 1, vector

Be baseline, i.e. the connecting line of two antennas, vector

And vector

Be respectively the distance of echo, then vector to antenna 1 and antenna 2 Be the three-dimensional position that will obtain;

The 3rd step, catch distance relation, to set up first and close tethers, the radar return that returns from ground must be to satisfy equidistant relation, this is a sphere relation, i.e. AD=AB+BD=AB+|BD|A, wherein, vector Be vector

Unit vector, be called and look vector;

The 4th step, catch phase relation, set up second and close tethers, in the radar video that two width of cloth antennas obtain, include phase information, the phase differential of two images of two width of cloth antenna correspondences satisfies certain relation, promptly satisfies hyperbolic relation;

$\mathrm{\Φ}=\frac{2\mathrm{\π}\left|\stackrel{\→}{\mathrm{BD}}\right|}{\mathrm{\λ}}[\sqrt{1-\frac{2\stackrel{\→}{\mathrm{BD}}\·\stackrel{\→}{\mathrm{BC}}}{{\left|\stackrel{\→}{\mathrm{BD}}\right|}^2}+{\left(\frac{\stackrel{\→}{\mathrm{BC}}}{\stackrel{\→}{\mathrm{BD}}}\right)}^2}-1]$

The 5th step, catch doppler frequency relation, set up the 3rd and close tethers, radar return includes phase information, along with the orientation to distribution, have frequency change, i.e. doppler frequency, multispectral rein in the speed that implied in the centre frequency an amount of with the relation of looking vector, promptly $f_d=\frac{2}{\mathrm{\λ}}\stackrel{\→}{A}\·\stackrel{\→}{V},$ This is a tapered relation;

The 6th step, the coordinate system of definition orthogonal basis, this is a most crucial step of the present invention, in the above-mentioned physical relation formula, the antenna of radar changes in time and moves, therefore, look vector change in time and change, it is crucial selecting correct suitable coordinate system, and the connecting line vector of choosing two antennas is first base, promptly $\stackrel{\→}{n_b}=\frac{\stackrel{\→}{\mathrm{BC}}}{\left|\stackrel{\→}{\mathrm{BC}}\right|},$ Second base is positioned at velocity plane, promptly ${\stackrel{\→}{n}}_c=\frac{\stackrel{\→}{V}-(\stackrel{\→}{V}\·\stackrel{\→}{n_b}){\stackrel{\→}{n}}_b}{|\stackrel{\→}{V}-(\stackrel{\→}{V}\·\stackrel{\→}{n_b}){\stackrel{\→}{n}}_b|},$ The 3rd base satisfies right-hand rule, promptly ${\stackrel{\→}{n}}_d=\stackrel{\→}{n_c}\×\stackrel{\→}{n_b};$

In the 7th step, because the choosing of above-mentioned orthogonal basis coordinate system, make the sight line vector

Problem solve and to become very direct, definition $\mathrm{BD}=\left|\mathrm{BD}\right|(a_1{n}_b+a_2{n}_c+a_3{n}_d),$ According to second phase relation formula, can get a ₁According to the 3rd doppler frequency relational expression, can get a ₂According to orthogonality, can get a ₃

The 8th step is by first distance relation, according to the sight line vector that obtains Can realize three-dimensional reconstruction.

Images