An automated monitoring system for the HF band

This article describes an automated monitoring system for the HF band. The system consists of several components like direction finder, emitter detection and tracking as well as classification and demodulation units. At first, we give a description of the architecture, before we explain the processing units and the user interface. With the support of the user interface, the operator specifies search orders. The detail of the results and the operating expense depends on the classification stage. So, the lowest classification stage delivers most of the search results with least information while the highest classification stage gives the modulation type, the modulation parameters and the protocol of the emissions.