Created attachment 467282 [details] kalibrate-rtl-0.4.1.ebuild Kalibrate, or kal, can scan for GSM base stations in a given frequency band and can use those GSM base stations to calculate the local oscillator frequency offset. This is a modified version of Kalibrate that works with the RTL-SDR. Depends on net-wireless/rtl-sdr and sci-libs/fftw drsn0w
GitHub repository found here: https://github.com/steve-m/kalibrate-rtl