A Method of Atmospheric Correction in Insar Measurement

Abstract

The invention discloses an atmospheric correction method during INSAR measurement. The method comprises the following steps of (1) using a WRF model to simulate a parameter needed during calculation of atmospheric delay, wherein the WRF model adopts GFS data as meteorological data; (2) calculating dry and wet atmospheric delay; (3) converting the atmospheric delay into phase delay; and (4) removing an atmospheric delay phase in an INSAR interference phase diagram. In the method, a mesoscale atmospheric model WRF is used to carry out atmospheric correction and the model can predict a weather condition and can reach a 1km resolution level, which is better than a prediction condition through using a method based on MERIS, MODIS and GPS data. By using the GFS meteorological data, a prediction data time interval is 3 hours and the data is updated for every 6b hours so that timeliness is high. A measurement result is accurate and the method is suitable for popularization and application.

Description

technical field [0001] The invention relates to the technical field of remote sensing, in particular to an atmospheric correction method in INSAR (Interferometric SAR, Synthetic Aperture Radar Interferometry) measurement. Background technique [0002] Atmospheric delay is one of the most important factors affecting the interferometric phase accuracy. Generally, the flight altitude of polar-orbiting SAR satellites is generally 500-800km. SAR electromagnetic wave propagation needs to pass through the ionosphere (the air layer from about 80km to 85-800km above the earth's surface) and the troposphere (the air layer from the earth's surface to 7-12km), thus being affected by the ionosphere. and tropospheric effects. In the ionosphere, the propagation of electromagnetic waves is delayed mainly due to the scattering effect of the ionized atmosphere; at the same time, due to changes in the total electron content (TEC) of the ionosphere, the propagation path of electromagnetic wave...

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Problems solved by technology

[0012] 1. The water vapor content data obtained by MERIS is affected by clouds, so in cloudy areas, the water vapor content of the data is not accurate

[0013] 2. This method is limited by the time resolution of MERIS data, the data receiving time is fixed, and the data time and the actual interferogram time will deviate, which will affect the calculation results

[0014] It can be seen that the above-mentioned existing atmospheric correction method obviously still has inconvenience and defects, and needs to be further improved urgently.

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