Chapter 5.1
• Test
  -- Problem Summary
  -- Variations Between Radars
  -- Beamwidth, ERP, and Low Voltage Summary
  -- TEST DATA
• Recommendations

This section summarizes the Police Traffic Radar ISSUE PAPER (DOT HS-805 254) -- U.S. Department of Transportation (DOT) - National Highway Traffic Safety Administration (NHTSA) dated February 1980.

The document is also available on the Internet at the Office of Law Enforcement Standards (OLES) web site (see Web Links page).

TEST

Seven radar units (six different models) from four different manufacturers were tested for problems. The study listed several recommendations to address problems encountered with some of the radars in the test. All the radar units tested operate at X band; two test models were handheld (the CMI radars), five test models were multi-piece radars.

The test data does not identify the exact radar model used but instead categorizes the radar units as A, B, C, D, E, F, and G (7 radars tested, 6 different models from 4 manufacturers). Note: * indicates from unofficial sources (not NHTSA). The test revealed several operational (chapter 5.4) and multiple interference (chapter 5.5) problems. Below is a summary of the test results.

RADARS AFFECTED  PERCENT  AFFFECTED BY

 A B C D E F       86%    patrol speed SHADOWING (moving mode)
 A B   D E F G     86%    internal 100 watt MOBILE RADIO
 A B C D   F G     86%    internal CB transmissions
 A B C - - F G     71%    PANNING error (ALL --100% -- 2 MODULE RADARs)
   B C D E F       71%    Mechanical Interference (SCANNING error)
 A B     E F G     71%    internal 2 watt HAND-HELD RADIO
   B C D E         57%    internal AC and HEATER FANS
   B   D   F       43%    SPEED BUMPING or BATCHING (moving mode)
 A B       F       43%    external POLICE RADIOS 20-30 ft away
     C D           29%    IGNITION AND ALTERNATOR
           F       14%    external CB transmissions

   B   D   F G     57%    TUNING FORK(s) mis-labeled or missing

All radars tested transmitted in band except for one -- radar F transmitted slightly out of X band (10.500-10.550 GHz) by 900 kHz (10.5509 GHz) and off center (10.525 GHz) frequency by 25.9 MHz.

OTHER MOVING MODE ABNORMALITIES;
• 40 mph radar (B) picked-up 37 mph Pinto then lost for several seconds before measuring another car way behind Pinto,
• 41 mph radar (D) tracked 57 mph truck well behind 35 mph Pinto before tracking Pinto,
• 41 mph radar (G) picked up 57 mph truck 100 yards (90 meters) behind 33 mph Pinto.

The NHTSA report indicates test radars D and E were haanheld units (panning error NA). Test Radars B and F are believed to both be MPH K-55 radars; however two discrepancies should be noted. Radar B measured beamwidth was 20.4 degrees, Radar F measured beamwidth was 24.6 degrees. Also the report indicates Radar B does not have a kill switch while Radar F does.

Also see Radar Specification (chapter 3.2).

RECOMMENDATIONS

Based on the test results the report suggested several recommendations as summarized below;

• Adopt radar standards and require police agencies to follow standards,
• Develop policy guidelines for radar maintenance, testing, and calibration,
• Keep adequate maintenance and calibration records,
• Establish minimum training standards,
• Develop State-level certification (renew every 1 to 3 years),
• Develop radar workshops and seminars for traffic adjudication personnel,
• Establish State-level policy/procedural guidelines to ensure proper use.

NHTSA recommended standards, based on the 1980 test, may be found under the title: Performance Standards for Speed Measuring Devices, United States Department of Transportation and National Highway Traffic Safety Administration, Federal Register, Volume 46, Number 5, January 8, 1981. Below is a list of some of the recommended specifications.

      Performance 
    Characteristics        Minimum Requirement
	
Frequency        X Band    10.525 GHz +/- 25 MHz
                 K Band    24.150 GHz +/- 100 MHz
 
Beamwidth        X Band    18 degrees
                 K Band    15 degrees

Minimum Detection Range    500 feet (150 meters)

Accuracy     Stationary    +/- 1 mph 
            Moving Mode    +/- 2 mph
                           +/- 1 mph (patrol car)

  Tuning Fork Tolerance    +/- 1/2 percent