Maritime VHF-DSC monitoring with low cost SDR receiver

Abstract

The main part of the alerting system of the GMDSS is done by automating alerting using Digital Selective Calling on VHF or MF/HF bands. Most of the small craft used to transport migrants use VHF-DSC to alert European's agencies of distress situations, which, in the all-most situations are fake. Because the maximum range of VHF propagation is around 50NM and it's related to the antennas' heights, it is necessary to increase the coverage area by installing many DSC receivers. The paper contains an example of a VHF-DSC receiver using a 20 Euros dongle and free GNU radio software. Instead to buy a maritime radio coast station the authorities can implement this system using low-cost dongle and small computers like Raspberry Pi, which also permit internet connection and IoT.