Patent ID: 7558695
Filing Date: 2009-07-07
Classification: G01S

Abstract:
1. A method of sensing vehicle speed comprising: self-powering a speed sensor, wherein the speed sensor comprises a Doppler speed sensor that includes a microwave source and a microwave receiver, which are designed to measure a speed corresponding to one or more objects using a Doppler shift in a microwave that a) originated from the microwave source, b) was received at the microwave receiver, and c) was back-reflected from one of the one or more objects; taking a sample of Doppler speed sensor data from the Doppler speed sensor; processing the sample of Doppler speed sensor data to calculate one or more speeds corresponding to the one or more objects; determining a traffic speed based at least in part on the one or more speeds calculated using the sample of Doppler speed sensor data; and wirelessly transmitting the traffic speed to a server.