Translator Disclaimer
21 September 2007 SCAF estimation of time delay and Doppler stretch
Author Affiliations +
The conventional cross-ambiguity function (CAF) process assumes that the transmitted signal is a sinusoid having slowly varying complex modulation, and models a received signal as a delayed version of the transmitted signal, doppler shifted by the dominant frequency. For wide-band transmitted signals, it is more accurate to model a received signal as a time-scaled version of the transmitted signal, combined with a time delay, and wide-band cross-ambiguity models are well-known. We provide derivations of time-dependent wide-band cross-ambiguity functions appropriate for estimating radar target range and velocity, and time-difference of arrival (TDOA) and differential receiver velocity (DV) for geolocation. We demonstrate through simulations that for wide-band transmission, these scale CAF (SCAF) models are signficantly more accurate than CAF for estimating target range and velocity, TDOA and DV. In these applications, it is critical that the SCAF surface be evaluated in real-time, and we provide a method for fast computation of the scale correlation in SCAF, using only the discrete Fourier transform (DFT). SCAF estimates of delay and scale are computed on a discrete lattice, which may not provide sufficient resolution. To address this issue we further demonstrate simple methods, based on the DFT and phase differentiation of the time-dependent SCAF surface, by which super resolution of delay and scale, may be achieved.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
D. C. Smith and D. J. Nelson "SCAF estimation of time delay and Doppler stretch", Proc. SPIE 6697, Advanced Signal Processing Algorithms, Architectures, and Implementations XVII, 669708 (21 September 2007);


Common aperture multiband radar (CAMBR)
Proceedings of SPIE (November 05 1996)
Pulse compression radar processing using low-bit ADC
Proceedings of SPIE (March 07 2003)
Estimation of the continuously varying Doppler effect
Proceedings of SPIE (May 13 2010)
Effects of channel tap spacing on delay lock tracking
Proceedings of SPIE (December 08 1995)
Multifunction CO2 Laser Radar Technology
Proceedings of SPIE (April 30 1982)

Back to Top