Abstract:
Recent experiments with the Littoral Sea Mine Test Vehicle (LSMTV) have provided a direct comparison of the performance of pseudorandom bipolar phase coded (BPPC) pulses for use in detection and localization of near-surface shallow-water targets. A February 1996 experiment at Ft. Lauderdale utilized a triplane of known target strength and position to evaluate various BPPC pulses with different Doppler and range resolutions. The purpose of this experiment was to measure the signal-processing gain by these pulse types against slow moving targets (1--3 kn) and compare it with the theoretical values for this environment. The target return was immersed in a white Gaussian noise background with volume and surface reverberation. Runs were made with the LSMTV on the ocean floor at 535 ft and triplane depths of 50 and 110 ft. The range craft was positioned so that it would drift through the test area. This study evaluates the resolution performance of these BPPC pulses via direct comparison to 0.5- and 32-ms cw pulses against the same target by sequencing the pulses during each target opportunity. Comparative performance results are presented for the measured signal processing gains and resolutions versus theoretical calculations. [Work supported by ONR.]