Number Stations, their Analysis with Python Signal Processing Library, FFT Algorithm and their use in Global Espionage

Abstract

Number stations are shortwave radio stations that send encrypted messages to clandestine operators on the field. These stations have been used for many years, but their existence has long been mysterious. This paper investigates how to analyze radio station signals using Python and the SciPy module. The history of number stations and the methods used to encrypt their signals are covered in the first section of this paper. The Fourier transform and the Fast Fourier Transform technique, which we'll employ to analyze the signals, are next briefly discussed. A WebSDR, or a Software-Defined Radio receiver, a web-based radio receiver we use to receive and record the audio, is part of our experimental setup. It also attempts to describe our experimental setup, which consists of a WebSDR, or Software-Defined Radio receiver, a web-based radio receiver that we use to receive, record, and analyze signals. The study's findings are then shown, along with frequency spectra and spectrograms of various number station signals.