Implementation of sonobuoy receiver using software defined radio

Today, software defined radio systems are superseding traditional radio communication systems rapidly. In this process flexibility and upgradeability of software plays an important role. In this project, a “Directional Frequency Analysis and Recording” (DIFAR) type sonobuoy receiver has been developed using software defined radio. Sonobuoy is a system that can be thrown from aircraft or ship for detecting submarines in the naval battles, underwater acoustic signals are transmitted to operator by means of radio waves. Traditional sonobuoy receivers perform demodulation and bearing calculation by means of analog systems or hybrid systems, and therefore high precision bearing values cannot be obtained. In order to reduce bearing errors and perform high precision analysis, a new sonobuoy receiver has been developed using software defined radio based on digital signal processing techniques, in this work. In the software development process, open source software, such as Python and GNU Radio has been preferred. It is possible to record the desired sonobuoy channel or compute the magnetic bearing angle with the developed system.