测绘学报 ›› 2023, Vol. 52 ›› Issue (12): 2066-2077.doi: 10.11947/j.AGCS.2023.20220624

• 大地测量学与导航 • 上一篇    下一篇

陆地水GNSS反演的格林函数和Slepian基函数比较分析

陈超1, 邹蓉1, 曹家铭1, 李瑜2, 梁宏3, 方智伟1   

  1. 1. 中国地质大学(武汉)地球物理与空间信息学院, 湖北 武汉 430074;
    2. 中国地震局中国地震台网中心, 北京 100045;
    3. 中国气象局气象探测中心, 北京 100081
  • 收稿日期:2022-11-03 修回日期:2023-06-28 发布日期:2024-01-03
  • 通讯作者: 邹蓉 E-mail:zourong@cug.edu.cn
  • 作者简介:陈超(1990-),男,博士生,研究方向为水文大地测量学、GNSS高精度算法、大地测量与地球物理学。E-mail:chaoshu@cug.edu.cn
  • 基金资助:
    国家自然科学基金(42274009)

Comparative analysis of Green's functions and Slepian basis functions for GNSS inversion of terrestrial water

CHEN Chao1, ZOU Rong1, CAO Jiaming1, LI Yu2, LIANG Hong3, FANG Zhiwei1   

  1. 1. Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China;
    2. China Earthquake Networks Center, China Earthquake Administration, Beijing 100045, China;
    3. Meteorological Observation Center of China Meteorological Administration, Beijing 100081, China
  • Received:2022-11-03 Revised:2023-06-28 Published:2024-01-03
  • Supported by:
    The National Natural Science Foundation of China (No. 42274009)

摘要: 陆地水是水资源中重要的组成部分,全球气候变暖会深远地影响陆地水分布,甚至恶化区域水资源供求关系。陆地水变化关乎人类社会发展,监测陆地水变化越来越重要。锚定在地壳上的GNSS连续观测站可直接测量地表位移的不断变化并反演水文荷载,使得GNSS技术成为研究陆地水的热点。目前GNSS反演陆地水主要有格林函数和Slepian基函数两种方法,两者在数学模型上是等价的,但实际应用上存在差异。本文在研究区域(云南地区97°E—107°E、20°N—30°N)使用相同数据,定量分析格林函数和Slepian基函数反演方法的差异,结果表明:①基于模拟数据,格林函数反演结果受GNSS测站数量和空间展布影响程度比Slepian基函数反演结果更大,而Slepian基函数反演结果受最大截断阶数的影响较大;同等情况下,格林函数反演结果总体精度比Slepian基函数反演结果更优。②基于实测的“陆态网络”和气象局的GNSS连续测站垂直时间序列数据,两种方法反演等效水高结果相关性达到0.98,Slepian基函数反演结果振幅比格林函数反演结果振幅平均大25%。③GNSS数据反演的陆地水和GRACE、GLDAS推断的陆地水相关性均大于0.65,并且与该地区月度降水数据一致性很好;GNSS反演等效水高序列波峰出现的时间比最大降雨滞后1~2个月。

关键词: GNSS, 格林函数, Slepian基函数, 陆地水储量, 等效水高

Abstract: Terrestrial water storage is an important part of water resources. Changes in terrestrial water storage are related to the development of human society. Atmospheric warming has a profound impact on the distribution of global terrestrial water storage, and even worsens the relationship between regional water supply and demand. With the construction of continuous GNSS station network in China, GNSS has become a new type of geodetic method for monitoring terrestrial water storage changes. At present, the methods for terrestrial water inversion using continuous GNSS stations are mainly divided into Green's function and Slepian basis function inversion methods, but there are few reports on the differences and applicable scenarios of those two methods. Starting from the basic principles of the two methods, this paper uses simulated data and measured GNSS data to perform inversion based on the Green's function and the Slepian basis function, respectively. Results show that: ① Based on the simulation data, the number and spatial distribution of GNSS stations are different, and the Green's function inversion results are more affected than the Slepian basis function inversion results. The overall accuracy of Green's function inversion results is better, and the Slepian basis function method is greatly affected by the maximum truncation order. ② Based on the real “land-state network” and the vertical time series data of GNSS continuous observation stations of the Meteorological Bureau, the correlation between the two methods to retrieve the equivalent water height is 0.98, and the amplitude of the Slepian basis function inversion result is 25% larger than that of the Green function inversion result on average. ③ The results of GNSS inversion and the terrestrial water phase inferred by GRACE and GLDAS are all greater than 0.65, and the monthly precipitation data are in good agreement. The peak of the equivalent water height sequence retrieved by GNSS lags behind the maximum rainfall by 1~2 months. Considered the reality in most area of China, the density GNSS stations is not enough for the application for Green's method in TWS inversion, so the Slepian method is the good choice.

Key words: GNSS, Green's function, Slepian basis function, terrestrial water storage, equivalent water height

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