Atmospheric Delay Correction Research And Software Design Of Spaceborne Laser Altimetry Data

The continuous improvement of satellite technology has driven the rapid development of spaceborne laser altimetry technology.The spaceborne laser altimeter plays an extensive role in glacial elevation measurement in the Arctic and Antarctic regions,forestry measurement,and environmental monitoring.This is due to its satellite-based platform,which covers most areas of the world and has high ranging accuracy.However,when the satellite laser altimeter is working,it will be affected by the external atmospheric environment,resulting in poor positioning accuracy of the laser altimetry data,which makes the measurement accuracy of disaster monitoring emergency,resource investigation,polar surveying,environmental monitoring and other related industries related to surveying and mapping have limitations,so it is necessary to establish an atmospheric delay correction model to analyze and study atmospheric delay errors and eliminate atmospheric delay errors.In response to this problem,this paper takes the laser altimeter carried by the Gaofen-7 satellite launched by our country not long ago as the research object.Firstly,the error source that affects the high-precision measurement of the satellite-borne laser altimetry system is used as the starting point for research,the rigorous geometric model and the error analysis of spaceborne laser altimeter are proposed;Secondly,establish an atmospheric delay correction model for the atmospheric delay error,the data released by GLAS is used to verify the accuracy of the model and analyze the sensitivity of atmospheric parameters to atmospheric delay errors;Finally,the atmospheric delay correction software is designed,with the HDF5 satellite laser height m easurement and foot print image simulation data stored in the HDF5 format provided by the Satellite Surveying and Mapping Application Center of the National Surveying and Mapping Geographic Information Bureau as experimental data,and the software is used to implement the experiment.The research content and specific work of this article are as follows:(1)The most representative satellite-borne laser altimetry systems in the world are summarized,their application characteristics and working principles are explained and analyzed;the rigorous geometric model is established,and its errors are analyzed.It has certain reference value for the error research of domestic laser altimeter.(2)Combining the parameters of Gaofen-7 satellite,the atmospheric delay correction model is established on the error caused by the refraction of the laser altimeter in the atmosphere,and the surface atmospheric pressure model is established to improve and supplement.The accuracy of the model is verified using the data published by GLAS.Substitute NCEP atmospheric data into the model to do experiments on sensitivity analysis of atmospheric delay errors.The calculation results show that the atmospheric correction value in the zenith direction is about 2.30 m,and it is concluded that the sensitivity of temperature and precipitable water to the atmospheric delay correction value is weak,and the sensitivity effect of the satellite altitude angle and the height of the measurement station on atmospheric delay correction stronger.(3)The software design for atmospheric delay correction research is carried out,and the sample data is used as software operation data for experimental analysis,which provides research reference for the processing of spaceborne laser altimetry data,and provides reference for improving positioning accuracy and subsequent launch conditions of spaceborne laser satellites.