CN-121978685-A - Double-star double-frequency-point InSAR satellite system overall design method and system

CN121978685ACN 121978685 ACN121978685 ACN 121978685ACN-121978685-A

Abstract

The invention provides a total design method and system of a double-star double-frequency point InSAR satellite system, wherein the method comprises the steps of determining the specification of a product mapped by the double-star double-frequency point InSAR satellite system, determining a target positioning equation of the double-star double-frequency point InSAR satellite system, determining a solution strategy of absolute phases of the double-star double-frequency point InSAR satellite system, designing SAR double-frequency points and working bandwidths of the satellite system, mapping index distribution of the double-star double-frequency point InSAR satellite system, designing a double-frequency cooperative working mode of the SAR system and designing an in-orbit working flow of the double-star double-frequency point InSAR satellite system. According to the invention, through the design of double-frequency collaborative imaging and full-link index distribution under double-star formation, the problems of dependence of absolute phase ambiguity on ground control points and time decoherence of heavy rail interference in the traditional InSAR mapping and resolving are solved, single-navigation, high-precision and uncontrollable global topographic mapping is realized, and the technical effects of greatly improving autonomous positioning capability of a system, mapping product quality and developing reliability are achieved.

Inventors

CHEN JUNLI
CHEN ZHONGHUA
CHEN XIZHI
ZHAO YAN
LI ANTAO
ZHAO DI
HOU YUSHENG
LIU YANYANG

Assignees

上海卫星工程研究所

Dates

Publication Date: 20260505
Application Date: 20260106

Claims (10)

1. The total design method of the double-star double-frequency-point InSAR satellite system is characterized by comprising the following steps of: Step S1, determining the mapping product specification of the double-star double-frequency point InSAR satellite system; S2, determining a target positioning equation of the double-star double-frequency-point InSAR satellite system; step S3, determining a resolving strategy of the absolute phase of the double-star double-frequency-point InSAR satellite system; s4, designing a satellite system SAR dual-frequency point and a working bandwidth; s5, mapping index distribution of the double-star double-frequency point InSAR satellite system; S6, designing a dual-frequency cooperative working mode of the SAR system; Step S7, designing an on-orbit work flow of the double-star double-frequency-point InSAR satellite system.
2. The method for designing the dual-star dual-frequency point InSAR satellite system as set forth in claim 1, wherein determining the mapping product specification of the dual-star dual-frequency point InSAR satellite system comprises: And determining the relative elevation precision and the absolute elevation precision index of the double-star double-frequency-point InSAR satellite system according to the precision requirements of 1:5000, 1:10000, 1:25000, 1:50000 and 1:100000 specified by the digital elevation model standard.
3. The method for designing the whole system of the double-star double-frequency point InSAR satellite system according to claim 1, wherein the determining the target positioning equation of the double-star double-frequency point InSAR satellite system comprises the following steps: The target positioning equation is a joint equation set combining a double-star orbit state, a baseline vector and a double-frequency interference phase: Wherein, the In order to observe the target point position vector, And Representing the position vector and velocity vector of the main star at the corresponding moment, Is the instantaneous baseline vector of the primary and secondary radars, And Respectively two working frequency points of the radar, Is the range of the radar of the main star, As the doppler center frequency is the frequency of the doppler, And Respectively is The main and auxiliary star of the frequency point interfere with each other, Is that The frequency point is used for assisting in the star interference moment, In order to achieve the light velocity, the light beam is, And The phase is respectively the double-frequency point interference unwrapping phase, And The absolute fuzzy numbers of the double-frequency point interferograms are respectively obtained.
4. The method for designing the total of the two-star and two-frequency-point InSAR satellite system according to claim 1, wherein the determining the solution strategy of the absolute phase of the two-star and two-frequency-point InSAR satellite system comprises: According to the observation geometric parameters of the double-star system, the fuzzy heights corresponding to the first frequency and the second frequency are calculated respectively And The calculation formula of the fuzzy height is as follows: Wherein, the For the view angle of the radar side, As a function of the wavelength(s), For the target point to SAR antenna distance, Is the vertical effective baseline length; Constructing absolute elevation equation for same ground point based on double frequency data acquisition, assuming wavelength And The absolute phase ambiguity numbers of the corresponding interference phase diagrams after unwrapping are respectively And Then And The following relationship is satisfied: Wherein, the For frequency The elevation corresponding to the unwrapped phase difference, For frequency The corresponding blur height is set to be equal to the blur height, Is the elevation of the ground point; For a pair of And Performing a two-dimensional traversal search, selecting to cause And (3) with Equal to And combining to determine the absolute phase ambiguity number of the interference phase map after unwrapping.
5. The method for designing the total design of the dual-star dual-frequency-point InSAR satellite system according to claim 1, wherein the method for designing the dual-frequency-point SAR satellite system and the working bandwidth comprises the following steps: mapping method for imaging by using double star double frequency points, same view angle, same region and same time of InSAR system, and main frequency is used at the head and tail of imaging respectively Auxiliary frequency Performing double-frequency imaging on the two frequency points to form interference pairs of the two frequency points; Configuring a dominant frequency point The frequency points of the interference mapping task are kept consistent, the same working parameters are set, the single-frequency interference data are acquired and connected in a seamless mode when the satellite data are acquired, and the difference value of the two frequency points is determined according to the frequency multiplication capacity of the SAR load reference frequency and the folding fuzzy number corresponding to the frequency difference; According to the resolution requirement of the mapping image, calculating SAR signal bandwidth B by using the following formula: Wherein, the In order for the resolution of the image to be high, In order to achieve the light velocity, the light beam is, Is SAR incidence angle; according to the calculation result of the signal bandwidth B and the available working frequency band of SAR, selecting two SAR working frequency points which are not interfered with each other And satisfies the following relationship: 。
6. the method for designing the whole system of the double-star double-frequency point InSAR satellite system according to claim 1, wherein the mapping index allocation of the double-star double-frequency point InSAR satellite system comprises the following steps: Analyzing by adopting a bistatic InSAR satellite height measurement precision analysis method based on a positioning equation; And distributing the elevation error index to satellite indexes of satellite orbit determination precision, speed measurement precision, SAR slant range precision and baseline measurement precision.
7. The method for designing the total design of the dual-star dual-frequency point InSAR satellite system according to claim 1, wherein the method for designing the dual-frequency cooperative work mode of the SAR system comprises the following steps: The double stars are configured to work in a winding flying formation state; control A star and B star to alternately adopt frequency points Transmitting radar waves to a target strip area, and controlling A star to receive double-frequency points The B star is receiving double frequency point at the same time of echo data Is provided; acquiring 4 ground elevation model data samples of the same target area through single navigation of formation satellites, wherein the data samples comprise frequency points DEM data acquired by simultaneous reception of lower A star emission and AB star and frequency point DEM data acquired by simultaneous reception of lower A star emission and AB star and frequency point DEM data and frequency points acquired by simultaneous transmission of lower B star and simultaneous reception of AB star And the acquired DEM data is simultaneously received by the lower B star transmission and the AB star.
8. The method for designing the whole double-star double-frequency-point InSAR satellite system according to claim 1, wherein the designing the on-orbit workflow of the double-star double-frequency-point InSAR satellite system comprises the following steps: the satellite system completes the double-star formation configuration design and the double-star double-frequency point wave position design of the InSAR satellite system according to task requirements; The measurement and control system calculates the over-roof time of the double stars to the same target area through the double star orbit forecast result, and calculates the over-roof time of the double stars to the ground data receiving station after the double stars are imaged; The operation control system calculates SAR working parameters of double-star double-frequency points according to the track forecast result, compiles a load instruction packet and transmits the load instruction packet to the measurement and control system to annotate satellites on a satellite-to-ground link, wherein the load instruction packet comprises a SAR instruction packet generation instruction packet and a data transmission instruction packet generation instruction packet; the satellite system controls SAR load start-up imaging in a target overhead period according to the load instruction packet, and controls the data transmission subsystem to transmit ground data in the overhead period of the ground data receiving station; The ground processing system receives data downloaded by the satellite, sequentially carries out SAR imaging processing and InSAR processing on the downloaded data, and finally obtains a mapping product.
9. The method for overall design of a dual-star dual-frequency point InSAR satellite system according to claim 8, wherein the satellite system controls SAR load start-up imaging in a target overhead period according to a load command packet, and controls a data transmission subsystem to transmit ground data in the overhead period of a ground data receiving station, comprising: the SAR subsystem performs bunching imaging on the target when passing through the top target area according to the SAR instruction packet; The data transmission subsystem records SAR imaging data during SAR imaging, and performs ground data transmission according to the data transmission instruction packet when passing through the overhead ground data receiving station.
10. The utility model provides a two star dual-frenquency point InSAR satellite system global design system which characterized in that includes: the method comprises the steps of determining the mapping product specification of the double-star double-frequency-point InSAR satellite system by a module M1; the module M2 is used for determining a target positioning equation of the double-star double-frequency-point InSAR satellite system; the module M3 determines a resolving strategy of the absolute phase of the double-star double-frequency point InSAR satellite system; The module M4 is used for designing a satellite system SAR dual-frequency point and a working bandwidth; module M5, mapping index allocation of the double-star double-frequency point InSAR satellite system; a module M6 for designing a dual-frequency cooperative work mode of the SAR system; And a module M7, designing an on-orbit workflow of the double-star double-frequency-point InSAR satellite system.

Description

Double-star double-frequency-point InSAR satellite system overall design method and system Technical Field The invention relates to the field of satellite overall design, in particular to a method and a system for overall design of a double-star double-frequency-point InSAR satellite system. Background Interferometric synthetic aperture radar (InSAR) is an important remote sensing means for acquiring a high-precision ground elevation model (DEM). The method utilizes two SAR antennas distributed along the vertical course to observe the same area at different visual angles, and carries out interference processing on the two obtained complex SAR images to obtain the difference of the slant distances between the phase centers of the main radar antenna and the auxiliary radar antenna and the target, so as to obtain the DEM of the observation area, as shown in fig. 2. The distributed satellite InSAR system installs two SAR on two satellites in formation flight for simultaneous earth observation, can overcome the problems of time decoherence, low baseline precision and the like faced by repeated navigation InSAR, and can acquire high-precision DEM. The method for mapping the InSAR double-frequency point, the same view angle, the same area and the same time imaging solves the engineering problem that the InSAR mapping satellite system can only rely on ground control data to solve the interference phase absolute ambiguity. The patent with publication number of CN114594473 discloses a method, a device and equipment for realizing double-frequency interference SAR (synthetic aperture radar) solution absolute phase difference ambiguity, which mainly focuses on the technology of double-frequency point ambiguity solution, and is insufficient for supporting the overall design of a satellite system, and the engineering operability of the overall design method of the satellite system is obviously stronger. The patent with publication number CN112526518B discloses a global seamless mapping design method and system for a distributed InSAR satellite, which mainly solves the problem of global seamless mapping of a single strip and has obvious differences in application direction, application range and technical approach from the overall design problem of the double-star double-frequency-point InSAR satellite system which is mainly solved by the invention. The patent with publication number CN115113204A discloses a satellite-borne InSAR implementation method of distributed satellite dual-band split emission, but the dual-band and dual-star InSAR working mode proposed by the patent mainly aims at improving the InSAR mapping precision of a satellite system instead of solving the problem of fuzzy engineering design, and has obvious differences in application direction and technical approach. The publication number is CN112379377B, a distributed InSAR satellite strip mapping optimization SAR task planning method and system are disclosed, but the patent mainly solves the problems of single strip task planning and optimization parameter selection, and has obvious differences in application direction, application range and technical approach. The patent with publication number CN112526518B discloses a global seamless mapping design method and system for a distributed InSAR satellite, but the patent mainly solves the problem of global seamless mapping of a single strip, and has obvious differences in application direction, application range and technical approach. The invention discloses a method and a system for analyzing distributed InSAR satellite height measurement precision influence factors, which mainly provides a mathematical expression of a double-star double-frequency-point InSAR height measurement model for the first time, and mainly solves the problems of double-star single-frequency-point InSAR height measurement precision influence factor analysis and system design, wherein the technical approaches are obviously different. In summary, to solve the above-mentioned problems in the prior art, research on a method and a system for designing an InSAR satellite system with two satellites and two frequency points becomes a critical task to be solved. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a method and a system for overall design of a double-star double-frequency-point InSAR satellite system. The total design method of the double-star double-frequency-point InSAR satellite system comprises the following steps of S1, mapping product specifications of the double-star double-frequency-point InSAR satellite system, S2, determining a target positioning equation of the double-star double-frequency-point InSAR satellite system, S3, determining a solution strategy of absolute phases of the double-star double-frequency-point InSAR satellite system, S4, designing SAR double-frequency points and working bandwidths of the satellite system, S5, mapping index distribution of the double-star