CalibrateSDR: Calibrating your SDR Frequency Offset with DAB+

Thanks to Andreas Hornig who has recently released a new program called 'CalibrateSDR' (GitHub code) which is designed to accurately determine the frequency offset of an SDR via an IQ recording of a DAB+ station. Cheaper RTL-SDR and SDRs use a low quality crystal oscillator which usually has a large offset from the ideal frequency. Furthermore, that frequency offset will change as the dongle warms up or as the ambient temperature changes. The end result is that any signals received will not be at the correct frequency, and they will drift as the temperature changes. Higher end SDRs and improved