Cross correlated doppler radar/infra red velocity and presence sensor

Abstract

A doppler radar and infra red sensor focused by common means onto a region, will, with appropriate cross correlation, provide improved velocity and presence sensing in a complex uncontrolled environment. The illustrative overhead, roadside traffic sensor employs a common microwave/infra red parabolic reflector and illuminating feed. The sensor can be conveniently mounted onto utility poles without cutting up the road or hanging overhead arbors. The velocity and presence data it provides can be used to determine vehicular headway, density, volume, vehicle size, aggregate momentum, aggregate congestion, platoon arrival, queue length, etc. This novel sensor reduces spurious indications, permits oblique angle viewing of vehicles, reduces doppler transmitter power levels so as to be well below normally accepted environmentally safe levels, and discriminates against vehicles moving in the wrong direction. The improved information will make possible better adaptive traffic signal timing methods to reduce fuel consumption and auto emissions. An additional feature provided by this sensor is that it detects emergency and mass transit vehicles to expedite their safe movement.