External calibration method of satellite-borne interferometric synthetic aperture radar (InSAR) system

Abstract

The invention discloses an external calibration method of a satellite-borne interferometric synthetic aperture radar (InSAR) system. The external calibration method comprises that sea surface height data is measured by a satellite height gauge, and average sea surface height data is acquired after time varying influence factors are removed; sea surface height data measured by the satellite-borne InSAR system is acquired through sea images and uncalibrated interference parameters of preset time and space distribution acquired by the satellite-borne InSAR system; sea height variation brought about by the time varying influence factors except for the spreading effect under the condition of the preset time and space distribution is calculated in a simulation mode; time varying synthesized sea surface height data is acquired by the average sea surface height and the sea surface height variation brought about by time varying influence factors except for the spreading effect; and the sea surface height data measured by the satellite-borne InSAR system is corrected by taking the time varying synthesized sea surface height data as standard data, thereby realizing calibration of the satellite-borne InSAR system. According to the invention, an external calibration method based on a sea field is adopted, thereby being capable of carrying out long-term dynamic monitoring on slow variation elements in error of the satellite-borne InSAR system.

Description

technical field [0001] The invention relates to the technical field of radar in the electronic industry, and in particular to an external calibration method of a spaceborne interferometric synthetic aperture radar (Interferometric Synthetic Aperture Radar, InSAR for short) system. Background technique [0002] The spaceborne InSAR system is a technology that uses the phase information of the synthetic aperture radar to extract the three-dimensional information and elevation change information of the ground surface. Elevation information for the scene. With the increasing requirements of the digital elevation model (Digital Elevation Model, DEM) measurement accuracy, the research on the calibration method of the spaceborne InSAR system is also more and more important. [0003] In InSAR, the main factors affecting the DEM measurement accuracy include: baseline length and baseline inclination measurement errors, system delay errors, interferometric phase offsets, etc. These er...

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Problems solved by technology

[0006] It is difficult and costly to lay out artificial point target calibration fields in areas with complex terrain, and the calibration field cannot be imaged frequently. It can only statically calibrate the fixed error of the system, and it is difficult to accurately reflect the changing characteristics of the error; the natural distribution target calibration field also has problems Frequently revisit the calibration field, unable to continuously monitor the spaceborne InSAR system for a long time, resulting in insufficient sampling, and unable to reflect the slowly changing part of the InSAR system error

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