A Software-defined Radio Ionospheric Chirpsounder for Hf Propagation Analysis

Advanced users of high frequency (HF) radio communications have long used systems known as chirpsounders 1 to obtain real-time information about the ionospheric propagation conditions of different communication channels between a transmitter and a receiver. Traditional chirpsounders are expensive to realize and lack the flexibility of state-of-the art digital radio platforms. However, the advent of Software Defined Radio (SDR) technology has created opportunities to provide a chirpsounder capability in a flexible, low-cost form. In this paper, we report on our development of a prototype Software Defined Radio (SDR) chirpsounder system based on a commercially-available SDR platform. The accurate realtime picture of ionospheric propagation provided at low cost by such a chirpsounder can be instrumental in providing HF communications users with self-configuring link optimization capabilities that dynamically select the best channels to be used in an HF link, to maximize communications capacity and reliability.