POWER BUDGET ANALYSIS OF REFLECTED GPS L1 AND L5 FREQUENCY SIGNALS FOR PASSIVE MICROWAVE IMAGING
Abstract
The GPS signals are commonly used for navigation purposes. Another utilization of reflected GPS signals is for remote sensing. This paper focuses on the power budget analysis of bi-static radar using GPS satellite as a “transmitter of opportunityâ€. In this application the direct and reflected GPS signals are acquired using customized hardware, where the receiver can be mounted on an airborne platform or remain static. GPS satellites currently transmit L1 frequency signals with C/A codes used as a ranging signal, but plans for transmitting additional L5 frequency signals as part of GPS modernization efforts are underway. Here we present the simulated results for power budget analysis of both GPS L1 and L5 frequency signals. The Signal to Noise Ratio (SNR) for different ranges is calculated and results have been plotted. It can be deduced that SNR of GPS L5 reflected signal is higher as compared to GPS L1 signal for similar target ranges and therefore, these signals are more suitable for remote sensing applications as compared to GPS L1 signals. Simulation is carried out in MATLAB®.References
E. P. Glennon, A. G. Dempster and C. Rizos,
Journal of Global Positioning Systems 5, No. 1
(2006) 119.
C. Zuffada and V. Zavorotny, Coherence Time and
Statistical Properties of the GPS Signal Scattered
Off the Ocean Surface and Their Impact on the
Accuracy of Remote Sensing of Sea Surface
Topography and Winds, California Institute of
Technology 7 (2001) p.2.
M. Usman and D.W. Armitage, Journal of Global
Positioning Systems 8, No 1 (2009) 87.
D. Masters and S.K., P Axelrad, Airborne GPS
Bistatic Radar Soil Moisture Measurements during
SMEX02, Proceedings of IEEE International
IGARSS (2003).
S.J. Katzberg, J.L. Garrison and Jr. Langley,
Utilizing GPS to Determine Ionospheric Delay
Over the Ocean Research Center, Hampton,
Virginia, USA (1996) .
J.L Garrison, A. Komjathy, V.U. Zavorotny and
S.J. Katzberg, IEEE Transactions on Geo-Science
and Remote Sensing 40, No. 1 (2002) p. 2.
M. Usman and D.W. Armitage, Acquisition of
Reflected GPS Signals for Remote Sensing
Applications, Advances in space Technologies
ICAST (2008).
M. Usman, A Synthetic Aperture Radar System
Using a Static Receiver for Passive Microwave
Imaging Purposes, IBCAST (2010).
V. Behar and C. Kabakchive, Detectability of Air
Targets using Bistatic Radar Based on GPS L5
Signals, International Radar Symposium IRC
(2011).
S. Erker, S. Thölert, J. Furthner and M. Meurer,
L5– The New GPS Signal in Proceeding of IAIN
(2009).
