Reception and Characterization of GPS Reflected Signals

Abstract

The application of reflected signals of global navigation satellite system (GNSS) has emerged in the last two decades as a feasible remote sensing scheme in retrieving various geophysical parameters of the Earth’s surface including ice layer land and sea In this thesis the GPS signals reflected off the sea surface are considered To ensure that the signals received by the antenna are reflected signals from the sea surface a procedure is proposed to detect and process the reflected signals The procedure is composed of two parts One is delay prediction and the other is delay estimation between line-of-sight signal and reflected signal In the procedure for delay estimation a threshold is set to identify candidate reflected signals from sea surface Furthermore the predicted delay and the delay estimation of candidate reflected signals are compared If the difference between the predicted delay and the delay estimation is within a certain chosen threshold the reflected signals are identified Several experiments are conducted and the received data are processed Thresholds about standard deviation of C/N0 and delay difference set in the procedure are determined from this experiment analysis The results in this thesis contain two experiments conducted on different days In both cases the GPS reflected signals from sea surface are identified using the proposed procedure The wind speed information is measured by an anemometer in the second experiment To correlate the results the simulations of link-budget analysis and delay-Doppler map are made The link-budget analysis provides the predicted C/N0 information Thereafter both simulation results are compared with the C/N0 estimation and delay-Doppler map extracted from experiment to further verify the detected signals are indeed reflected signals

Date of Award	2014 Aug 15
Original language	English
Supervisor	Jyh-Chin Juang (Supervisor)