The Cross-Ambiguity Function for emitter location and radar - practical issues for time discretization

Abstract

The difference between continuous time and discrete time Cross-Ambiguity Functions can be significant. Both narrow band and wide band CAFs can be computed exactly with discretization, but the usual implementation of the narrow band CAF introduces an error which increases with FDOA. The error is largest for signal modulations with non- symmetric CAF plane signatures and for large FDOA values. The wide band CAF is unaffected by this deficiency whether or not a variable delay/variable rate filter is employed. Simple and relatively low cost post-processing can largely correct the discretization error for the narrow band CAF.