{'fraction_non_alphanumeric': 0.019981834695731154, 'fraction_numerical': 0.0009082652134423251, 'mean_word_length': 5.678787878787879, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
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.