Multi-polarization SAR load internal calibration mode design and data analysis method

Abstract

The invention relates to a multi-polarization SAR load internal calibration mode design and data analysis method. The method comprises the following steps: step 1, designing a multi-polarization SAR satellite internal calibration mode and a signal path, wherein the multi-polarization SAR satellite internal calibration mode comprises noise calibration, full array surface calibration and single T / Rchannel calibration; 2, recording and downloading internal calibration data based on a set internal calibration mode and a signal path; and 3, analyzing the internal calibration data, calculating system gain from the internal calibration data, obtaining an antenna pattern, constructing a reference function of a transceiving channel, and acquiring time delay and noise power of the transceiving channel. According to the invention, the multi-polarization SAR satellite can cover the whole transmit-receive link through the design of a calibration mode and a signal path, so that the method can obtain the real linear frequency modulation signal, system gain calibration, antenna directional diagram and gain monitoring of the system through calibration data.

Description

technical field [0001] The invention belongs to the field of microwave remote sensing satellites, and in particular relates to a multi-polarization SAR payload internal calibration mode design and data analysis method. Background technique [0002] SAR calibration technology is the key technology to realize SAR quantitative remote sensing. The purpose of calibration is to measure various uncertain factors that affect the quality of SAR imaging, remove their influence during data processing, and establish an accurate relationship between image intensity and backscatter coefficient of ground objects. According to the different calibration process, calibration is divided into internal calibration and external calibration. Internal calibration is the process of injecting calibration signals into the radar data stream by using the internal equipment of the system to describe the performance of the radar system. External calibration is the process of using ground signals to desc...

AI Technical Summary

Problems solved by technology

[0003] The existing internal calibration methods are mainly designed for single-channel and single-polarization systems, and do not have the ability to calibrate multi-channel and multi-polarization SAR loads; in addition, the existing methods cannot determine whether the working status of the SAR load subsystem is normal through the internal calibration data. To judge, and do not have the ability to test the pattern, it is necessary to measure the antenna pattern through the actual transmission and reception of the near-field antenna array

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