A Method for Continuous Observation of Coverage Area of ​​Synthetic Aperture Radar in Geosynchronous Orbit

Abstract

The invention discloses a method for a geosynchronous orbit synthetic aperture radar to continuously observe a coverage area. The method comprises the steps of firstly, determining an orbit segment, meeting observation application requirements, of a satellite according to the longitude and latitude of an area to be observed, calculating the distance between the satellite to a target area in the selected orbit segment, when the beam of an antenna points to the target area, taking the coordinates of the target under an antenna coordinate system as coordinates A and the coordinates of the target under a geocentric fixed coordinate system as coordinates B, transferring the coordinates A and the coordinates B into the same coordinate system so that the expressions of the coordinates A and the coordinates B contain a control variable for realizing beam pointing, and then obtaining the desired controlled quantity by equating the coordinates A with the coordinates B under the same coordinate system. The satellite pitching-rolling combined implementation model of the method is not limited by the scanning capacity of the antenna and sall in attitude control angle, and therefore, continuous observation, by the geosynchronous orbit synthetic aperture radar, to a ground fixed target area, can be realized.

Description

technical field [0001] The invention belongs to the field of synthetic aperture radar, and relates to a method for realizing continuous observation of a coverage area by a geosynchronous orbit synthetic aperture radar. Background technique [0002] Existing SAR satellites usually have an orbit of 500km to 800km. Due to the limitation of orbital height, the coverage area is small, the surveying band is narrow, and the repeated observation period is long, which limits its application to a large extent. For example, at present, Radarsat-II, the spaceborne synthetic aperture radar with the widest mapping bandwidth in the world, has a mapping width of 500 km at a resolution of 100 meters, and a typical repeated observation period is about 2 days. For battlefields and sudden disasters, such observation capabilities cannot meet the needs. [0003] In order to overcome these weaknesses, people have proposed some solutions. At present, the most common design idea is to use multiple ...

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Problems solved by technology

The first ALOSSAR image provided by the Japanese Space Agency was received 30 hours later, the second Italian Cosmo-Skymed radar image was received 48 hours later, and the observation image of my country's SAR satellite was obtained 52 hours later. The response time is far from meeting the disaster emergency needs

But so far, the research on GEOSAR at home and abroad has mostly focused on system performance analysis, imaging processing, etc., and there are few research results on GEOSAR's large coverage and long-term continuous observation. There are fewer studies on observation implementation methods, and no relevant literature has been retrieved

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