34.6 GHz across-the-road calibrator/simulator designed and tested by NIST. (News Briefs).

Across-the-road photo radars are increasingly used for speed limit enforcement on the nations highways. During the past 10 years, NIST has played an important role in developing new instrumentation that is to be used for type certification of these traffic radars. In February 2000, we completed an analog calibrator/simulator designed for use with K-Band (24.1 GHz) radars and demonstrated its use in calibrating a commercial Doppler radar to an accuracy of [+ or -] 1 mph at simulated vehicle speeds of 65 mph. NIST subsequently received further support from the National Highway Traffic Safety Administration (NHTSA) through the Office of Law Enforcement Standards to develop another unit capable of calibrating similar radar systems that operate at Ka-Band (34.6 GHz). The microwave design of the 34.6 GHz calibrator is identical to that of the 24 GHz calibrator, but is software driven. The flexible software controls the Doppler frequency shift and signal time duration, thereby simulating to a [+ or -] 2 % uncertaint y the radar return for different vehicles from motorcycles to trucks moving at speeds of up to 120 mph. Lab testing is complete. The units will be delivered to a NHTSA type-certification laboratory.

CONTACT: Claude Weil, [phone]; [e-mail] or Robert Johnk, [phone]; [e-mail] or David Novotny, [phone]; [e-mail].