Abstract: A traffic radar unit capable of looking past the lead vehicle of oncoming traffic and discovering and identifying a violator employs master and slave antennas having diverging boresights that provide overlapping relative power density radiation patterns. The radar return signal from a target of interest is received by each antenna to produce two independent Doppler signals of the same frequency which are processed by respective master and slave signal processing channels. In the illustrated embodiment, a reference boresight is established in the overlapped patterns such that a target position along the reference boresight occurs at the time that the amplitudes of the two Doppler signals are equal. Controllable high pass filters whose passbands are shifted upwardly in response to return signals of increasing amplitude attenuate stronger, lower frequency interfering signals.

Abstract: A one-piece traffic radar unit has a housing containing both the transceiver and signal processing circuitry and the directional antenna of the radar system. A bracket plate extends from the top portion of the housing and overlies the dashboard of the patrol vehicle to mount the unit therein with the housing depending from the bracket plate in front of the dashboard, thereby leaving the driver's view through the windshield unobstructed. The antenna is of the conical horn type and is vertically disposed to beam the transmitted signal up through the housing to a rotary reflector mounted on the top of the housing. The reflector is rotatable about a vertical axis and permits the operator to aim the beam in any horizontal direction through the windshield or a window of the vehicle. A special safety mount for the reflector provides for 360.degree. rotation and also permits the reflector to break away from the housing on impact.

Abstract: A traffic radar unit capable of operation from a moving patrol vehicle has a receiver provided with phase recognition circuitry that prevents the display of "ghost" readings. After initial processing of the incoming composite Doppler signal, the phase recognition circuitry receives logic conditioned, low and high frequency speed signals derived from the Doppler signal and produces an abort command to prevent the determined target speed from being displayed if the phase relationship between the two speed signals remains constant for a predetermined number of cycles of the low frequency speed signal. The latter signal corresponds to a low frequency component of the Doppler signal representing the speed of the patrol car, but the high frequency signal may be a harmonic that would produce an invalid reading. The circuitry employs a serial to parallel type shift register having a data input receiving the high frequency speed signal. The register is clocked by the low frequency speed signal.