Design of an Integrated GPS Receiver for the Processing of Reflected GPS Signals

摘要

In the paper, the design and development of a highly integrated GPS receiver for the processing of reflected GPS signals will be described. Several design considerations have been analyzed in order to successfully acquire and track weak, reflected GPS signals from ground and surface. First of all, both RHCP and LHCP antennas are employed so that direct and reflected signals can be acquired. A special antenna housing is designed so that the antenna beam can be slew to the desired direction. Depending on applications, such directions may be along the reflected signal path or even along the line-of-sight of a particular satellite. Appropriate signal conditioning and amplification are then used to feed signals into the receiver front end without sacrificing sensitivity. Unlike most existing GPS reflection experiments, the goal of the study is to exploit the carrier phase components of the reflected signals. To this end, several modifications are made in the tracking loopsrnAn integer ambiguity resolution algorithm has also been implemented. During the development and testrnstage, GPS pseudolites are used to generate reflected signals so that the receiver as well as associated software is appropriately tuned so that both direct and reflected signals can be processed.