卫星测高已经发展为成熟的海洋观测技术,然而在内陆水域的观测精度仍有待提高,其关键在于消除雷达回波中“陆地污染”效应的影响。在近海波形净化技术的基础上,针对内陆水域特点,提出了改进的波形净化技术,用于剔除回波中“陆地污染”导致的异常波峰。在净化波形的基础上,结合优化的重跟踪算法进行波形重跟踪改正,达到提高内陆水域测高观测精度的目的。利用青藏高原中的多个湖泊的水文站数据进行精度检验,结果显示利用波形净化技术消除异常波峰后的波形进行重跟踪改正,平均精度可达到15.8 cm,相较ICE-1算法和阈值法的精度分别提高了14%和27%,表明本算法可有效探测并消除雷达回波的异常峰值,有效提高内陆水域的测高数据观测精度。
Abstract
Satellite altimetry has developed into a mature marine observation technique. But the precision of observation in inland waters needs to be improved, the key of which is to eliminate the effects of land pollution in radar echo. On the basis of the coastal waveform decontamination technology, we propose an improved waveform retracking algorithm for the characteristics of inland waters to eliminate the abnormal peaks caused by land pollution in altimeter waveform. Subsequently, the decontaminated waveform is used for retracking correction to improve the precision of satellite altimetry in inland waters. The measured water level data of several lakes in Qinghai-Tibet Plateau is used for precision testing. The experimental results show that the waveform decontamination technology can eliminate the abnormal peaks in the offshore area, then retrackers are used for the corrected waveform, and the average precision reaches 15.8 centimeter, which is 14% and 27% higher than the accuracy of ICE-1 algorithm and thresholoding method. The results demonstrate that the algorithm can effectively detect and eliminate the abnormal peak of radar waveform and improve the observation accuracy of altimetry data in inland waters.
关键词
卫星测高 /
内陆湖泊 /
波形净化技术 /
重跟踪算法 /
异常波峰
Key words
satellite altimetry /
inland lake /
waveform decontamination technology /
waveform retracking algorithm /
abnormal peak of radar waveform
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基金
国家自然科学基金项目(41974016、41904031);江西省自然科学基金项目(20202BAB214029、20202BABL214055);raybet体育在线
开放基金项目(CKWV2019773/KY)
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