Vehicle Length Estimation Using an LTE Transmitter Combined With a Software-Defined Receiver

Unobtrusive determination of an intruding vehicle's length is useful for threat assessments in perimeter surveillance, law enforcement, and antiterrorism applications. We describe a passive radar architecture wherein a broadcast signal from a cellular mobile communication system radio transmitter is bistatically scattered by a moving vehicle and received and processed in a software-defined radio platform. Measurement of the maximum Doppler frequency and the target viewing time combined with the known geometry of the measurement scenario permits the estimation of the target vehicle's length. Good agreement is observed between actual and estimated lengths for various vehicle types.