Wideband Signal Detection with Software DSP Processor Implemented on a Microcontroller

The results of testing a module for detecting a broadband hydroacoustic signal in a given frequency band are presented. The analog part of the module includes a microphone (hydrophone) with a preamplifier and a bandpass filter. The digital part of the module is implemented on a microcontroller designed to digitize the analog hydroacoustic signal and run the software for time processing, and recording the detected signal. The signal is digitized at up to 70 kHz at 12 bit resolution. Detection is performed by averaging the signal strength in a sliding window and comparing the values obtained with a dynamically changing threshold. The dynamic threshold is obtained on the basis of previous statistics of the momentary values of the signal power, averaging them in the window of the selected length, and multiplying them by a coefficient taking into account the level of false alarm. Detection is fixed when the signal level in the current window exceeds the level of the dynamic threshold.