Remote Sensing Soil Moisture & Classification by using Reflected GPS Observations, L1 & L2 Reflectivity
Shen, L-C.¹; Juang, J-C.^2
1Earth Science Academy, National Cheng Kung University; ²Electronic machine Department, National Chung Kung University

In the paper, Application and development of a highly integrated GPS receiver with reflected GPS signals for Ground Object Detection and soil moisture will be described. Several application considerations have been analyzed in order to successfully acquire and track weak, reflected GPS signals from ground surface. First of all, both RHCP and LHCP antennas are employed so that direct and reflected signals can be acquired simultaneously. The direction of arrival of the signals may be along the reflected signal path or even along the line-of-sight of a particular satellite. Unlike most existing GPS reflection experiment, the goal of the study is to exploit the carrier phase, reflectivity of L1/L2 SNR components of the reflected signals and direct signals for dry soil, wet soil, bare soil and concrete object detection on surface. The soil moisture with GPS reflectivity should be established like as data base for visual elements index at laboratory. An integer ambiguity resolution algorithm has also been implemented. During the development and test stage, the DTED and visual elements of satellite's images has been used and mapped with the integrated software. But the results predict the difference of reflected altitude and DTED level 2 height data (pixel resolution ~ 30 m, altitude's resolution ~ 10 m) are among -0.1 m and -3.5 m for the reflected area of water body, dry and wet soil sediment. Index Terms' Reflection coefficient, Object detection, Soil classification, Stream flow