Acoustic Random Noise Radar Using Ultra Wide Band Waveforms

Ultra wideband noise radar gives high range resolution and the range ambiguity is suppressed as a result of the non-periodic waveform. Random noise waveforms could also be applied in acoustic radar (Sodar/Sonar). Both wave generation and signal processing can then be performed on a PC. As a result, some signal processing algorithms used in random noise radar/sodar can be tested simpler using sound waves. This paper presents basic relationships and algorithms for signal processing in random noise radar/sodar, and the noise floor generated by the randomness of the transmitted signal is defined. A PC-controlled acoustic radar with ultra wide band random noise waveform (1-8 kHz) was implemented to test some of the algorithms described Measurements were carried out on both moving objects and stationary scenes. Moving target indication using stretched time processing (Doppler) and change detection algorithms were tested as well. Recording from a bridge shows the potential use of the technique for water level indication as an example.