GNU radio open source vehicle detector

Vehicle detection has been dominated for several decades by magneto-inductive sensors including inductive loop sensors. The detection electronics estimate the frequency of an oscillator that changes dependent upon the inductance of the sensor. The algorithms used to estimate the sensor inductance and to detect vehicles are proprietary and vary between manufacturers. This has limited research in this area to using only data provided through manufacturer specific interfaces. Since the signal provided by the sensor is a frequency modulated (FM) signal, communications demodulation techniques may lead to advances in detection and higher fidelity vehicle signatures. This paper describes an open source vehicle detector that is based upon the GNU (GNU's Not Unix) Radio open source software defined radio project.