Using reflected signal power from the BeiDou geostationary satellites to estimate soil moisture
Using reflected signal power from the BeiDou geostationary satellites to estimate soil moisture
复制标题
利用北斗静止卫星反射信号功率估算土壤湿度
DOI：
10.1080/2150704x.2018.1519272
复制
发表时间：
2018-10
影响因子：
2.3
通讯作者：
Gong JianYa
中科院分区：
文献类型：
--
作者：
Yan SongHua;Zhang Nan;Chen NengCheng;Gong JianYa
摘要星载微波传感器对地球表面的土壤湿度非常敏感，但由于卫星的重复周期，它们的性能受到其连续变化的足迹的限制。近年来，全球导航卫星系统（GNSS）微波信号已被用于估计土壤湿度，北斗系统（BDS）提供了新的信号源。与全球定位系统不同，北斗系统包括五颗地球静止轨道卫星。由于其轨道是地球同步轨道，地球同步轨道卫星的覆盖区对于固定接收器几乎保持不变;这一特性有利于对固定区域的反射研究进行连续长期观测。我们进行了一个基于地面的实地实验，并收集了数据，其中包括从GEO卫星和原位土壤水分观测的信号，在这个实验中，调查土壤水分估计使用的反射BDS信号的功率。本文首先设计了一个滤波器来分离地球同步轨道微动对原始信号的影响。然后计算并标定了反射系数。最后，利用反射系数估算了固定区域内每半小时的连续土壤湿度。结果表明，除雨天土壤水分变化较快外，估算值与实测值基本一致，平均绝对误差小于2.37%。该实验表明，北斗卫星系统地球同步轨道卫星是全球导航卫星系统反射测量法所用数据的一个重要来源。
ABSTRACT Satellites-based microwave sensors are sensitive to soil moisture at the surface of the Earth, but their performance is limited by their continuously varying footprints due to the repeat cycle of satellites. In recent years, Global Navigation Satellite System (GNSS) microwave signals have been used to estimate soil moisture and the BeiDou system (BDS) provides new signal sources. Unlike Global Positioning System, BDS includes five geostationary earth orbit (GEO) satellites. Because their orbits are geosynchronous, the footprints of the GEO satellites remain nearly unchanged for fixed receivers; this property is beneficial for continuous long-term observation of reflection studies in the fixed area. We conducted a ground-based field experiment and collected data that included signals from GEO satellites and in situ soil moisture observations during this experiment to investigate the soil moisture estimation using the power of the reflected BDS signals. In this letter, we first designed a filter to separate the effect of GEO slight motion on raw signal. We then calculated and calibrated reflection coefficient. Finally, we estimate the continuous soil moisture in the fixed area per half hour using the reflection coefficient. The results show that the estimated soil moisture changes are largely consistent with the in situ soil moisture data except rainy days in which soil moisture changes rapidly and the mean absolute error of the estimation is less than 2.37%. This experiment demonstrates that the BDS GEO satellites represent an important source of data for use in GNSS reflectometry.
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DOI：
10.1002/0471224286
发表时间：
2000-07
期刊：
--
影响因子：
--
作者：
L. Tsang;J. Kong;K. Ding
通讯作者：
L. Tsang;J. Kong;K. Ding
DOI：
10.1109/igarss.2003.1293916
发表时间：
2003-07
期刊：
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477)
影响因子：
--
作者：
V. Zavorotny;D. Masters;A. Gasiewski;B. Bartram;S. Katzberg;P. Axelrad;R. Zamora
通讯作者：
V. Zavorotny;D. Masters;A. Gasiewski;B. Bartram;S. Katzberg;P. Axelrad;R. Zamora
DOI：
10.1109/tgrs.1985.289498
发表时间：
1985-01-01
影响因子：
8.2
作者：
DOBSON, MC;ULABY, FT;ELRAYES, MA
通讯作者：
ELRAYES, MA
影响因子：
5.2
作者：
Chew, Clara;Shah, Rashmi;Mannucci, Anthony J.
通讯作者：
Mannucci, Anthony J.
影响因子：
13.5
作者：
Katzberg, SJ;Torres, O;Masters, D
通讯作者：
Masters, D