Prototype Software-based Receiver for Remote Sensing Using Reflected GPS Signals

D. Manandhar, R. Shibasaki, H. Torimoto

Abstract:	A reflected GPS signal contains information about the reflecting object since the characteristics of the reflected signal varies a lot depending upon the reflecting object. Though, this information may not be useful for accurate position computation, it may help us to identify the reflecting object itself, which is a type of remote sensing. Besides, by measuring the time delay of the reflected signal, it is possible to estimate the extra path length the reflected signal has to travel. Hence, in general, the analysis of reflected signal can be used for two broad categories of altimetry and remote sensing. GPS signal being in L-band provides good response for remote sensing applications like soil moisture estimation. The difference of reflection coefficient of dry soil and wet soil is about 10 times at L-band. Another important merit is being passive type of remote sensing. The GPS signal is already available in the space for 24 hours covering almost all the parts of the globe continuously. However, this type of analysis is rather limited with current commercial GPS receivers. We are in the process of developing a software-based GPS receiver that is capable of reflected signal analysis for remote sensing purpose. The receiver consists of a pair of RHCP and LHCP antenna, a front-end device, PC and necessary software for signal processing. In this paper, we discuss about the system architecture and algorithms, results of reflected signal analysis observed at different places in different conditions and antenna types. In order to demonstrate the capability of altimetry, we compute the height of antenna using relative chip delay between the RHCP and LHCP antenna.
Published in:	Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006) September 26 - 29, 2006 Fort Worth Convention Center Fort Worth, TX
Pages:	643 - 652
Cite this article:	Manandhar, D., Shibasaki, R., Torimoto, H., "Prototype Software-based Receiver for Remote Sensing Using Reflected GPS Signals," Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006), Fort Worth, TX, September 2006, pp. 643-652.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In