Method for extracting elevation of height measuring foot point through CryoSat-2 SARIn mode L1b level waveform data

Abstract

The method discloses a method for extracting an elevation of a height measuring foot point through CryoSat-2 SARIn mode L1b level waveform data. The method comprises the following steps of 1) extracting echo coherence and differential phase information from the CryoSat-2 SARIn mode L1b level data; 2) carrying out smoothing processing on echo coherence and differential phase data; 3) carrying out threshold segmentation according to echo coherence, and taking an area where the coherence is greater than a threshold as an alternative area; 4) merging the alternative areas to obtain an effective differential phase to be unwrapped; 5) carrying out relative phase unwrapping in a time delay direction; 6) calculating an three-dimensional coordinate of an elevation point through a differential phase;7) converting a reference coordinate system; and 8) carrying out absolute phase unwrapping based on an external DEM. In the invention, a high-precision height measuring foot point elevation can be obtained from L1b level data; compared with L2 level data released by ESA, there is a larger foot point coverage density, and the digital elevation model with a higher resolution can be acquired to obtain a finer terrain.

Description

technical field [0001] The invention relates to a satellite altimetry data processing technology, in particular to a method for extracting the height of an altimetry foot point through L1b level waveform data of a CryoSat-2 SARIn mode. Background technique [0002] The mass loss of glaciers is often considered as one of the early catastrophes caused by global warming, and the change of mass balance of glaciers is an important factor affecting global climate and sea level. As climate change becomes more apparent, there is an urgent need to understand how glaciers on Earth's surface, especially in polar regions, are changing. The emergence of satellite altimetry technology has changed the way people observe the polar regions. Based on high-precision satellite altimetry observations, we have the ability to systematically conduct scientific research related to the polar regions. Over the past few decades, satellite altimetry technology has been widely used in ice sheet topograp...

AI Technical Summary

Problems solved by technology

In October 2005, ESA launched the CryoSat satellite. Unfortunately, due to the failure of the launch vehicle, the satellite disappeared before entering orbit.

However, the traditional method of extracting ice sheet elevation based on satellite altimetry foot points cannot give full play to the advantages of the SARIn model, and cannot fundamentally solve the legacy problems of poor DEM acquisition accuracy and low resolution in the Antarctic continental margin region

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