THE INFLUENCE OF THE TERRAIN ON HEIGHT MEASUREMENT USING THE GNSS INTERFERENCE SIGNAL
THE INFLUENCE OF THE TERRAIN ON HEIGHT MEASUREMENT USING THE GNSS INTERFERENCE SIGNAL
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DOI：
10.2528/pierm18101402
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发表时间：
2019
影响因子：
1
通讯作者：
N. Zhang;Songhua Yan;Wenwei Wang;J. Gong
中科院分区：
文献类型：
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作者：
N. Zhang;Songhua Yan;Wenwei Wang;J. Gong
全球导航卫星系统（GNSS）反射率测量技术是一种很有前途的测量土壤湿度、海面高度、冰层性质等地球物理参数的技术，而干扰信号技术是测量这些地球物理参数的重要方法。该方法的效果与地形和接收天线的布置密切相关。本研究旨在透过模拟与实地实验，探讨地形与天线位置对测高的影响。本文首先利用抛物方程法模拟了不同地形条件下的干扰信号，分析了地形对测高的影响。然后进行了三个典型的田间试验，并对试验数据进行了处理。仿真和实验结果表明，干扰信号受地形和接收天线位置的影响。在地面平坦的情况下，水平视天线和天顶视天线的测高结果都是正确的。然而，当地面不平坦时，接收天线附近的土壤块导致估计误差。采用天顶天线比水平天线能更好地抑制附近地形的影响，从而获得更高的估计精度。当接收天线附近有斜坡时，如果高仰角减去斜坡等效于低仰角，则高仰角信号可能会产生明显的干扰效果。在这种情况下，测量高度是天线与斜坡表面之间的距离。
Global Navigation Satellite System (GNSS) reflectometry is a promising technology used to estimate soil moisture, sea surface height, ice properties, etc. Interference signal technique is an important method to estimate these geophysical parameters. The effect of this method is closely related to the terrain and the receiving antenna placement. This study aims to investigate the effects of terrain and antenna placement on height measurement through simulation and field experiments. In this paper, we first simulated the interference signal in different types of terrain by parabolic equation method and analyzed the influence of terrain on the height measurement. Then we conducted three typical field experiments and processed experimental data. The simulated and experimental results indicate that the interference signal is affected by the terrain and the receiving antenna placement. Height measurement result is correct by both horizontal-looking and zenith-looking antenna when the ground is flat. However when the ground is not flat, the soil block near the receiving antenna leads to estimation errors. A more accurate estimation is obtained by using zenith-looking antenna to suppress the influence from the near terrain than horizontal-looking antenna. When a slope is near the receiving antenna, the signal with a high elevation may achieve an obvious interference effect if high elevation minus slope is equivalent to a low elevation. In this situation, the measurement height is the distance between the antenna and slope surface.