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International Association of Chiefs of Police

1. Page 2 2 Requirements 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module 2 4 Tuning Fork Calibration When tested in accordance with 5 4 2 the frequency of oscillation of each tuning fork shall be within 2 of that specified by the manufacturer 2 5 Tuning Fork All ATR devices shall be designed to respond to the signal from either a mechanical or electronic tuning fork for purposes of checking the operation of the ATR signal processing function 2 5 1 Mechanical Tuning Fork If the ATR device is designed to respond to the signal from a mechanical tuning fork it shall be tested in accordance with 5 5 1 and display a speed reading within 2 km h 1 mph of the nominal speed of the tuning fork corrected if necessary for the cosine effect 2 5 2 Electronic Tuning Fork If the ATR device is designed to respond to the signal from an electronic tuning fork it shall be tested in accordance with 5 5 2 and display a speed reading within 2 km h 1 mph of the nominal speed specified by the manufacturer 2 6 Microwave Transmission The microwave characteristics of transmission frequency and frequency stability input current stability radiated output power stability antenna horizontal beamwidth and antenna near field power density shall be measured in accordance with 5 6 and shall meet the following requirement 2 6 1 Transmission Frequency and Frequency Stability When operated at th
2. true speed as described in 5 18 2 This may be accomplished by means of a second appropriately delayed image showing the target vehicle crossing a specified reference line Page 2 8 Requirements 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Section 3 Test Conditions 3 1 Standard Test Conditions Allow all measurement equipment to warm up until the system has achieved sufficient stability to perform the measurements Unless otherwise specified perform all measurements under standard test conditions 3 1 1 Standard Temperature Standard ambient temperature shall be between 20 C 68 F and 30 C 86 F 3 1 2 Standard Relative Humidity Standard relative humidity shall be between 10 and 85 3 1 3 Standard Supply Voltage For a nominal 12 V dc automotive system the standard supply voltage shall be 13 6 V 0 1 V The standard supply voltage characteristics of other types of battery supplies will be defined as needed A well filtered electronic power supply capable of a voltage adjustment of 25 from the nominal shall be used for laboratory testing and is recommended for other tests in place of the battery for safety and convenience The standard supply voltage shall be applied to the input terminals of the dc supply cables including all connectors and circuit protectors as furnished by the manufacturer Adjust the standard supply to within 1 of its specified voltage 6 1 04 Te
3. 0 141 COAXIAL STUB 50 Q MICROWAVE SECTION CLOCK amp LOGIC SECTION DIRECTION SELECTOR COUNTER gt SWITCH EC Eeleren MULTIPLEXER 2 DRIVER sideband Wa External START RAMP Chir CONTROL SELECTOR NUP LOGIC Timing DURATION SELECTOR VOLTAGE Externa GENERATOR CLOCK Input Figure 2 The ATR radar target simulator 5 6 1 04 Appendix Page A 5 Speed Measuring Device Performance Specifications Across the Road Radar Module Audio frequency synthesizer Oscilloscope Microphone Figure 3 The tuning fork calibration setup Page A 6 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Pick up horn Standard supply Frequency counter Figure 4 The transmission frequency and frequency stability measurements setup 6 1 04 Appendix Page A 7 Speed Measuring Device Performance Specifications Across the Road Radar Module Manufacturer s power cable Variable voltage supply Figure 5 The input current and low supply voltage measurements setup Page A 8 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Field intensity Standard supply meter Figure 6 The radiated output power stability measurement setup 6 1 04 Appendix Page A 9 Speed Measuring Device Performance Specifications Across the Road Radar Module Antenna turntable or rotor Receivi
4. 2 1 11 Temperature The highest and lowest temperature at which the unit is designed to operate 2 2 1 12 Displacement distance The shortest distance between the ATR device and the monitored lane of traffic c f figure 1 2 2 1 13 Temperature and Humidity The highest temperature and humidity combination at which the radar device is designed to operate 6 1 04 Requirements Page 2 1 2 2 2 Tuning Fork Applicable tuning fork s shall be submitted to support testing 2 2 2 1 External tuning fork Each tuning fork shall be accompanied by a calibration certificate including as a minimum 2 2 2 1 1 Serial number The serial number of the tuning fork 2 2 2 1 2 Design speed The nominal design speed 2 2 2 1 3 Frequency calibration A frequency calibration at 21 C 70 F 2 2 2 1 4 Frequency band The microwave frequency band for which it is to be used X K or Ka 2 2 2 1 5 Associated radar speed The calibrated frequency and associated radar speed in km h or mph based on conventional down the road radar Doppler frequencies 2 2 2 1 6 Correction factor Any correction factor that must be applied to the 21 C 70 F calibration speed when used at another temperature 2 2 2 2 Electronic tuning fork The nominal frequency of the oscillator and the nominal design speed displayed upon test by a properly functioning ATR device 2 2 3 Image Recording Equipment The image recording equipment shall be submitted to support testing where applicable Th
5. When tested according to 5 8 the ATR device shall not display any erroneous readings at or below the threshold voltage that activates the indicator A blank display is not an erroneous reading 2 9 Doppler Audio if applicable Where applicable the Doppler audio output characteristics of audio output and volume control shall be tested in accordance with 5 9 The ATR device shall emit a Doppler audio tone that is correlated with the received Doppler signal and any interference present and it shall have an audio volume adjustment control 2 10 Reserved 2 11 Power Surge The power surge characteristics exhibited when switching the ATR device from off to on shall be tested in accordance with 5 11 Switching the ATR device from off to on shall not cause any erroneous speed readings with a vehicle present 2 12 Speed Display The speed display characteristics of display readability display speed lock control display clear function internal circuit test function and auxiliary displays shall be tested in accordance with 5 12 and shall meet the following requirements 2 12 1 Display Readability The display shall be clearly readable when tested in accordance with 5 12 1 and used as intended by the manufacturer 2 12 2 Display Speed Lock Control If applicable the speed lock switch shall preserve the displayed vehicle speed readings require manual actuation and not recall a previous reading 2 12 3 Reserved 2 12 4 Intern
6. Wiper Motor Interference When subjected to a negative ramp sawtooth wave signal of 1 V p p with a maximum positive rise time of 2 us over a frequency range of 200 Hz to 10 000 Hz the ATR device shall not display any erroneous readings Page 2 6 Requirements 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module 2 15 3 Simulated Police FM Transceiver Interference When subjected to a 10 mW frequency modulated FM radio frequency signal in each police radio frequency band the ATR device shall not display any erroneous speed readings 2 15 4 Simulated Citizen Band CB AM Transceiver When subjected to a 5 mW amplitude modulated AM radio frequency in any of the CB channels specified in 5 15 4 the ATR device shall not display any erroneous speed readings 2 16 Radiated Electromagnetic Interference The operational test requirements of radio frequency transceiver interference and speed accuracy shall be tested in accordance with 5 16 An ATR device powered by a battery pack and designed to also use a nominal 12 V automotive system and adapter as an optional source of power shall also be tested for operability under requirement 5 16 1 for police FM transceiver interference utilizing this adapter During these tests a blank target speed display shall not be considered an erroneous reading Each ATR device shall meet the following requirements 2 16 1 Police FM Transceiver Interference The ATR d
7. accurately While it is impossible for this test to be exhaustive the test engineer shall look for the following controls that are unmarked or marked in a misleading way modes of operation that are not documented misleading labels appearing in an alphanumeric display lack of clarity in the manual including possible typographical errors No misleading wording is permitted on the control panel and display or in the manual If an undocumented mode does turn up e g engineering test mode the resulting display shall be clearly different from the display appearing in a normal speed measurement mode 5 3 2 Tuning Fork Labeling Examine each tuning fork and verify that it is properly marked as specified in 2 3 2 5 4 Tuning Fork Calibration 5 4 1 Mechanical Tuning Fork For an ATR device accepting a mechanical tuning fork measure the tuning fork frequency using a microphone audio amplifier and frequency counter or else the test equipment shown in figure 3 In the latter case adjust the audio frequency synthesizer to approximate the tuning fork frequency The tuning fork frequency is determined by multiplying the labeled tuning fork speed when expressed in km h by 19 5061 31 3906 when expressed in mph for X band radar devices and by 44 7595 72 0301 when expressed in mph for K band radar devices For Ka band radar devices the transmitted nominal microwave frequency must be specified to determine the tuning fork frequency For Ka band rad
8. blank display shall not be considered an erroneous reading Reset the ATR device controls for an approaching automobile Page 5 6 Test Procedures 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module with the automobile threshold speed switch set to 101 km h 63 mph Reset the simulator controls for an automobile receding at 104 km h 65 mph Activate the operate switch on the ATR device and trigger the simulator Verify that there is no indication of a speeding violation A reading of 00 error or a blank display shall not be considered an erroneous reading Repeat all of the steps in the above procedure for trucks and motorcycles 5 14 Reserved 5 15 Conducted Electromagnetic Interference Position the ATR device in front of the speed simulator centering the radar beam on the aperture of the simulator Connect as in figure 9 the other test equipment to the ATR device and set the standard supply voltage Turn on the simulator and set its controls to simulate the signal of a 104 km h 65 mph passing vehicle Activate the ATR device and allow it to complete its self test Set the ATR device controls to seek vehicles in both directions and verify that it is interacting with the simulator and correctly measuring the simulated speed 5 15 1 Simulated Vehicle Alternator Interference Test 5 15 1 1 Frequency Dependence Set the pulse generator output to 1 V p p or 7 5 of the standard supply voltage whiche
9. instructions Complete instructions for installing the ATR device including precautions to minimize or avoid interference from vehicle ignition heater air conditioner defroster blowers or other potentially interfering components 2 2 1 2 Operating Instructions Complete operating instructions including test procedures internal circuit test data required maintenance and any operating characteristics that are indicative of or symptomatic of possible malfunction of the radar device 2 2 1 3 Power supply Nominal power supply voltage and currents with and without displays illuminated with and without target present and in standby mode if appropriate 2 2 1 4 Frequency The nominal microwave frequency 2 2 1 5 Supply voltage The lowest and highest supply voltage level at which the radar is designed to operate the low voltage alert threshold value and display behavior 2 2 1 6 Microwave power density The maximum microwave power density mW cm measured in a plane 5 cm 2 in distant from the front of the antenna 2 2 1 7 Horizontal beamwidth The antenna horizontal beamwidth in degrees 2 2 1 8 Design angle The angle in degrees at which the ATR device is designed to operate with respect to the path of the targeted vehicle c f figure 1 2 2 1 9 Polarization The transmitted electric field polarization e g linear or circular and orientation 2 2 1 10 Operating speed The minimum and maximum operating speed of the ATR device 2
10. radar return signal received when the source and the radar reflecting target are in motion relative to one another 1 4 14 Erroneous Reading an incorrect target speed displayed by the radar device i e one that is not due to a target vehicle or which is not within the required accuracy tolerance of the speed of a target vehicle excluding known correction factors such as the cosine effect 1 4 15 Far field Region 8 that region beyond the close proximity of a transmitting antenna generally considered to begin at a radial distance R defined by the relationship 2d H R gt where d is a length characteristic of the antenna aperture and is the wavelength of the transmitted frequency in consistent units Page 1 2 General Information 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module 1 4 16 Frequency Band a designation for the assigned frequency range in which the radar device operates Current frequency assignments for police traffic radar devices are X band 10 500 MHz to 10 550 MHz K band 24 050 MHz to 24 250 MHz and Ka band 33 400 to 36 000 MHz 1 4 17 Internal Circuit Test a test function whether manually or automatically initiated that verifies that all radar device internal signal processing circuitry except for the microwave transmitter and receiver is working correctly i e all target and patrol signals will be properly processed and displayed 1 4 18 Low V
11. result 5 12 Speed Display Each time a test method requires that the ATR device be connected to the simulator the ATR device shall also be connected to the standard supply voltage source and properly aligned on the simulator Turn the simulated target signal off and proceed with each of the tests 5 12 1 Display Readability Test Establish a simulated target speed and verify that the display is clearly readable when used as intended by the manufacturer 5 12 2 Display Speed Lock Test if applicable Establish a simulated target speed and then activate the speed lock switch on the ATR device to retain that target speed reading Next increase the target speed then discontinue the simulated target and verify that the target speed display retains the original speed reading Clear the ATR device of the speed reading and establish another simulated target speed but do not activate the speed lock switch Discontinue the simulated target speed wait for the target speed display to blank and then activate the speed lock switch Verify that the target speed display remains blank Next activate any one of the control switches on the ATR device except standby and test and verify that the previous speed reading has not been preserved Repeat this for each control switch 5 12 3 Reserved 5 12 4 Internal Circuit Test Activate the ATR device and perform the internal circuit test in accordance with the instructions of the manufacturer Verify that
12. with the speed simulator Connect the ATR device and the display if applicable to the standard supply voltage and turn it on After energizing wait 2 min before performing any measurements The ATR device shall meet the requirements of 2 7 1 within 15 min of operation Repeat the above procedure at the required high temperature 2 C 3 6 F 5 7 2 Operational Humidity Test Place the ATR device excluding any image recording and other display equipment in the environmental chamber and adjust the relative humidity in the chamber to 90 at 37 C 2 99 F 3 6 F Allow the chamber to reach these conditions and maintain them for at least 8 h Using protective gloves remove the ATR device from the chamber place it in the test location positioned such that the center of the radar beam is directly in line with the speed simulator Connect the ATR device and the display if applicable to the standard supply voltage and turn it on After energizing wait 2 min before performing any measurements The ATR device shall meet the requirements of 2 7 2 within 15 min of operation Repeat the above procedure at the required high temperature 2 C 3 6 F 5 8 Low Supply Voltage Connect the ATR device and the display if applicable to the standard supply voltage as shown in figure 5 and energize it Allow the ATR device to stabilize for 2 min then conduct the appropriate speed accuracy test of 5 5 Continue to measure the radar speed whil
13. 1 replace the FM signal generator of the previous test by the AM signal generator 5 15 4 1 Frequency Dependence Set the generator to a frequency of 27 MHz with an output of 5 mW as measured by the power meter with no more than 1 mW reflected power and adjust the generator modulation to 99 Maintain the simulator speed at 104 km h 65 mph while slowly varying the modulation frequency from 200 Hz to 10 kHz and back to 200 Hz Verify that no erroneous readings appear at any time on the ATR display 5 15 4 2 Amplitude Dependence Repeat the above procedure using a constant modulation frequency of 1 5 kHz while slowly varying the AM signal generator output from 0 mW to 5 mW and back to 0 mW Repeat the procedure again using a constant modulation frequency of 3 1 kHz 5 16 Radiated Electromagnetic Interference The following roadside tests shall be performed in noise free environment void of extraneous moving objects such as ventilation fans or other cars not involved in the tests The ATR device shall be installed in a vehicle of a type commonly used by law enforcement The ATR antenna shall be positioned with respect to the frame of the vehicle in accordance with instructions from the ATR device manufacturer This vehicle shall have a permanently installed police FM transceiver and provision for powering a CB radio 5 16 1 EM Transceiver Interference Test Start the vehicle engine and set it to a fast idle Switch on its FM transceiver and acti
14. 5 17 1 1 for an approaching vehicle 5 17 1 1 3 Sensitivity to Displacement Distance Repeat procedure 5 17 1 1 1 for an automobile moving at 50 km h 30 mph However for this test the displacement distance shall be varied Displacement distances of 6 m 20 ft 8 m 26 ft and 10 m 33 ft shall be used and if the distances are judged to be safe 3 m 10 ft and 2 m 6 ft For each distance record the readings of the ATR device and the reference speed meter as the test vehicle passes through the ATR device beam Repeat three times and verify that the average ATR device reading and the average reference reading at each displacement distance agree with the requirements of 2 17 2 5 17 2 Unattended Operation Repeat the tests of 5 17 1 1 supplemented by the manufacturer s secondary method for proving that the evidential image correctly identifies the offending vehicle and its speed 5 18 Vehicle Determination Field Operation If requested by the ATR device manufacturer test the unit for both attended and or unattended operation Install and connect the supplied imaging equipment in accordance with instructions provided by the manufacturer Insure the antenna and the image recording equipment are oriented for the direction of enforcement whether operating in the receding mode or approaching mode 5 18 1 Attended Operation 5 18 1 1 Direction Discrimination 5 18 1 1 1 Approaching Mode Place the ATR device in the approaching m
15. 6 Antenna Primary Beam the radiation pattern of the antenna enclosed by the angle between the two first minima of radiated power on each side of the antenna centerline The main lobe of an antenna radiation pattern excluding all microwave power radiated in the sidelobes 1 4 7 Attended Operation an operator is an integral part of the evidence acquisition process 1 4 8 Cosine Effect the effect due to the target not traveling directly toward or away from the radar device The effect is always to lower the Doppler shift frequency in direct proportion to the cosine of the angle between the direction of travel and a line from the radar device to the target 1 4 9 Design Angle the angle at which the across the road radar device is designed to operate with respect to the path of the targeted vehicle cf figure 1 1 4 10 Displacement Distance the distance from the ATR device to the monitored lane of traffic cf figure 1 1 4 11 Display a visual readout device used to show vehicle speed and other useful information 1 4 12 Doppler Audio an audible signal that is generated by driving a loudspeaker with the Doppler shift beat frequency or with the Doppler shift beat frequency divided by a fixed factor provided that changes in the audio frequency correspond directly to changes in the speed of a target vehicle and any ambient interference present is discernible 1 4 13 Doppler Shift the magnitude of the frequency change of the
16. Being careful not to vary the distance from the antenna aperture use the isotropic probe to search for the maximum signal strength in the plane 5 cm 2 in from the antenna aperture or lens face Move the probe to obtain the 6 1 04 Test Procedures Page 5 3 maximum reading and record it 5 6 6 Standby Operate Switch When an ATR device is so equipped connect the ATR device as in figure 8 to the standard supply and energize it Allow the ATR device to stabilize for 2 min Use the isotropic probe and field density meter to verify that no rf power is transmitted unless the standby operate switch is closed Verify that transmission commences without due delay when the switch is closed and ceases without delay when the switch is opened 5 7 Environmental Extremes These tests should be conducted in an anechoic chamber or a site where reflecting objects are minimal or an open ground plane with absorbing materials placed on the ground surface to disperse the reflected signal 5 7 1 Operational Temperature Test Place the ATR device excluding any image recording and other display equipment in the environmental chamber and adjust the chamber temperature to within 2 C 3 6 F of the required low temperature Allow the chamber to reach thermal equilibrium and maintain it at this temperature for 30 min Using protective gloves remove the ATR device place it in the test location positioned such that the center of the radar beam is directly in line
17. International Association of Chiefs of Police 2004 Across the road Radar Performance Standards Volume 1 Dated June 1 2004 SPEED MEASURING DEVICE PERFORMANCE SPECIFICATIONS ACROSS THE ROAD RADAR MODULE This document is available to the public from the National Technical Information Service Springfield VA 22161 Speed Measuring Device Performance Specifications Across the Road Radar Module FOREWORD This document contains the across the road radar speed measuring device performance specifications developed under an Interagency Agreement with the National Institute of Standards and Technology Office of Law Enforcement Standards By defining minimum performance requirements and verification procedures this technical document establishes a base line for acceptable across the road radar speed measuring device performance Citizens courts and law enforcement officers should be assured that those across the road radar speed measuring device models determined by test to comply with these specifications will provide the high quality service they require Across the road radar equipment buyers should use these performance specifications as a model to develop purchasing criteria It is recommended that these specifications be incorporated into procurement documents requiring that devices offered for purchase meet as a minimum these specifications Manufacturers are encouraged to produce across the road radar speed measuring d
18. al Circuit Test Function The ATR device shall have a self test function that when activated determines if the internal signals will be processed and displayed to within 2 km h 1 mph The ATR device shall display the correct reading s when performing the internal circuit test function or the ATR device shall display an error message at the end of the test if the test function fails It shall not be possible for the ATR device to lock in speeds displayed by this test The internal circuit test switch shall not be labeled cal or calibrate 2 13 Signal Processing 6 1 04 Requirements Page 2 5 The signal processing characteristics listed below shall be tested in accordance with 5 13 and shall meet the following requirements Moreover these tests shall include all vehicle types and displacement distances 2 13 1 Speed Accuracy When tested in accordance with 5 13 1 the ATR device shall display a speed reading within 2 km h 3 km h 01 times actual speed 1 mph 2 mph 01 times actual speed of the signal produced by the speed simulator 2 13 2 Minimum and Maximum Speed When tested in accordance with 5 13 2 the ATR device shall accurately measure speeds down to 32 km h 20 mph It shall further accurately measure speeds up to 160 km h 100 mph or the highest speed at which the manufacturer states that the unit will operate properly whichever is higher 2 13 3 Reserved 2 13 4 Limiting Speed When tested in acc
19. ar devices the tuning fork frequency is calculated by multiplying the labeled tuning fork speed expressed in km h by 1 853720 2 983135 when expressed in mph times the nominal microwave frequency expressed in gigahertz i e frequency in megahertz divided by 1000 of the particular radar device Strike the mechanical tuning fork on a nonmetallic object wait 3 s then hold it in front of the microphone while adjusting the synthesizer frequency to obtain a stationary circular Lissajous pattern on the oscilloscope Record the tuning fork frequency directly from the synthesizer dials Divide the synthesizer frequency or the frequency as measured by the counter by the appropriate constant given above to obtain the speed corresponding to the measured frequency of the tuning fork 6 1 04 Test Procedures Page 5 1 5 4 2 Electronic Tuning Fork For an ATR device responding to an electronic tuning fork measure and record the frequency of this oscillator using a frequency counter attached to the electrical connector provided by the manufacturer for this purpose 5 5 Tuning Fork 5 5 1 Mechanical Tuning Fork For an ATR device responding to a mechanical tuning fork orient the ATR antenna so no moving targets are in its view and set the ATR controls to seek both approaching and receding targets Activate the tuning fork by striking it on a nonmetallic object and hold the tuning fork at a distance of 2 5 cm to 10 cm 1 in to 4 in in front of the antenna
20. ber shall be large enough to hold the ATR device and shall produce air temperatures from 30 C to 60 C 22 F to 140 F and relative humidity in the range of 90 to 95 while shielding the items under test from heating or cooling air currents blowing directly on them The temperature of the test items shall be measured with a thermometer separate from the sensor used to control the chamber air temperature and shall have an uncertainty no greater than 1 C 2 F Likewise humidity shall be measured with a hygrometer separate from the sensor used to control humidity and shall have an uncertainty no greater than 2 4 5 Anechoic Chamber The anechoic chamber shall be shielded to exclude outside interference and shall be constructed to minimize internal microwave reflections from the chamber wall floor and ceiling 6 1 04 Test Equipment Page 4 1 4 6 Microwave Frequency Counter The microwave frequency counter shall be capable of measuring microwave frequencies from 10 500 MHz to 10 550 MHz from 24 050 MHz to 24 250 MHz and from 33 400 MHz to 36 000 MHz with a measurement uncertainty no greater than 1 part in10 4 7 Field Strength Meter The field strength meter and accompanying isotropic probe shall be capable of measuring E field power densities at a minimum detection level of 0 01 mW cm with an uncertainty no greater than 1 dB 4 8 Isotropic Probe The isotropic probe shall have sensor antennas consisting of three
21. cal self resonant device which when activated produces oscillations that may be used to generate a pseudo Doppler frequency reference in the microwave receiver circuit of the ATR device 1 4 29 Unattended Operation an operator is not an integral part of the evidence acquisition process 6 1 04 General Information Page 1 3 1 4 30 UUT unit under test 1 4 31 Vehicle Length refers to the length of the target vehicle and consequently determines the duration of its Doppler signature 1 4 32 Vehicle Type target vehicles including motorcycles automobiles or trucks addressed by this standard Page 1 4 General Information 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Section 2 Requirements 2 1 Manufacturer Provided Equipment Each across the road radar device submitted for testing in accordance with the provisions of these specifications shall be accompanied by the minimum equipment as identified in the operating manual and or required by the testing laboratory The manufacturer shall supply any adapters or unique test equipment required to test the UUT Refer to the IACP Speed Measuring Device Testing Program Administrative Guide for complete details 2 2 Manufacturer Provided Information 2 2 1 ATR Device Each ATR device submitted for testing in accordance with the provisions of this document shall be accompanied by the following minimum information 2 2 1 1 Installation
22. dar beam After the signal decreases again below 20 dB the step can be increased to 1 Continue until the ATR antenna has been rotated through 180 A plot of the received power versus angle gives the antenna pattern desired From this plot determine the exact angle at which the received power is maximum the two angles at which the power decreases to one half of maximum 3 dB points and the two angles at which the received power decreases to one hundredth of the maximum 20 dB points Calculate and record the beamwidth or angular difference between the 3 dB points Calculate and record the angle that is exactly halfway between the 3 dB points and that is halfway between the 20 dB points The angle of maximum radiated field and the two calculated centers of the radar beam shall all be within 0 5 of the design angle specified by the manufacturer If this is not the case separate the ATR antenna and the receiving antenna by at least 4 m 13 ft and repeat the above procedure A more sensitive receiver or spectrum analyzer may be needed in this case Again determine the 3 dB and 20 dB beamwidths and the center of the radar beam Verify that the received power is greater than 20 dB below the maximum only within the main radar beam Reposition the antenna and repeat the above test procedure to determine the vertical beamwidth 5 6 5 Antenna Near Field Power Density Test Connect the ATR device to the test equipment as shown in figure 8
23. device in the receding mode The ATR device shall not record the images any automobile 5 18 2 Unattended Operation Repeat the tests of 5 18 1 supplemented by the manufacturer s secondary method for verifying that the evidential image correctly identifies the target vehicle and its speed 6 1 04 Test Procedures Page 5 11 Speed Measuring Device Performance Specifications Across the Road Radar Module APPENDIX 6 1 04 Appendix Page A 1 Speed Measuring Device Performance Specifications Across the Road Radar Module Table 1 Speed Errors Due to Misalignment Alignment Error Percent Speed Degrees 104 km h 65 MPH Note This table is optimized for a 20 cosine effect within 0 5 and is usable for design angles within 15 to 25 Page A 2 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Table 2 Minimum Performance Specifications for ATR Speed Measuring Devices Performance Characteristics Minimum Requirement Tuning Fork Frequency Tolerance 2 of the manufacturers specifications Radar Device Tuning Fork Speed 2 km h 1 mph Tolerance T S mp X Band 10 525 MHz 25 MHz K Band 24 150 MHz 100 MHz Ka Band 33 400 MHz to 36 000 MHz 100 MHz of the nominal value Radiated Output Power Variation 1 5dB X Band 12 maximum Antenna Horizontal Beamwidth K Band 6 maximum Ka Band 6 maximum Antenna Near Field Maximum 5 mWiem 2 6 5 Power Dens
24. e decreasing the supply voltage at the rate of approximately 0 2 V s until the low voltage alert is activated Record the supply voltage level Verify that no erroneous speed reading is present Slowly increase the supply voltage until the low voltage indicator is deactivated and again conduct the appropriate speed accuracy test 5 5 to verify that the ATR device displays the same speed reading as at standard supply voltage Page 5 4 Test Procedures 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module 5 9 Doppler Audio if applicable Place the ATR device in a suitable location Position the speed simulator 1 m 3 3 ft from the ATR device aligning the horn of the speed simulator with the center of the radar beam Connect the ATR device to the standard supply voltage source turn it on and allow it to complete its self test routine Set the ATR controls to seek approaching vehicles turn on the simulator and set its controls to simulate an 80 km h 50 mph approaching vehicle Trigger the simulator and listen for a tone corresponding to the speed reading 2 9 Repeat the above test for receding vehicles 5 10 Reserved 5 11 Power Surge Leave the ATR device and speed simulator set up as in the previous section Establish a simulated vehicle speed of 80 km h 50 mph Switch the state of the ATR device several times between power off and power on Verify that no erroneous readings are introduced as a
25. e image recording equipment submitted for testing in accordance with the provisions of these specifications shall be accompanied by the following minimum information 2 2 3 1 Installation instructions Complete instructions for connecting the supplied image recording equipment to the ATR device and verifying their operation including test procedures required maintenance and operating conditions indicative or symptomatic of a possible malfunction of the ATR system 2 2 3 2 Operating instructions Complete instructions for operating the supplied image recording equipment 2 3 Manufacturer Labeling 2 3 1 ATR Device Each control panel and remote control of the ATR device including supplied image recording equipment shall be marked with the functions and setting of all switches controls and displays It shall not be possible to set the controls to a functional mode of operation that is not marked and explained in the user s manual 2 3 2 External Tuning Fork The manufacturer shall permanently mark each external tuning fork with the following information 2 3 2 1 Serial number A serial number 2 3 2 2 Frequency band The microwave frequency band for which it is to be used X K or Ka 2 3 2 3 Speed specification A nominal stationary mode radar speed specification including units km h or mph 2 3 2 4 Ka band Each Ka band tuning fork with the nominal microwave frequency of its ATR device or marked with a code representing the same
26. e standard supply voltage 3 1 3 the transmission frequency shall be within the assigned frequency band of 10 500 MHz to 10 550 MHz for an X band ATR device 24 050 MHz to 24 250 MHz for a K band ATR device and 33 400 MHz to 36 000 MHz for a Ka band ATR device For a device intended to operate from a nominal 12 V automotive system the transmission frequency shall remain within the assigned frequency band if the voltage is raised 20 above the standard supply voltage or to the manufacturer s specified limit if higher and when lowered 20 below the standard supply voltage or to the manufacturer s specified lower voltage limit if lower In addition for Ka band ATR devices the frequency shall remain within 100 MHz of its nominal value For devices utilizing a battery pack the requirements shall be met if the voltage is raised to the manufacturer s specified upper limit and reduced to the manufacturer s specified lower limit An ATR device powered by a battery pack and designed to also use a nominal 12 V automotive system and adapter as an optional source of power shall also be tested for transmission frequency and frequency stability utilizing this adapter and a standard supply voltage of 13 6 V 20 2 6 2 Reserved 6 1 04 Requirements Page 2 3 2 6 3 Radiated Output Power Stability The microwave carrier output power shall not vary by more than 1 5 dB from its nominal value when the standard supply voltage is varied 20 2 6 4 A
27. ed of up to 144 km h 90 mph through the ATR beam During a test the driver or an assistant shall record the speed measured within the confines of the ATR beam using the reference speed meter The readings shall be communicated to the test coordinator who shall compare the ATR and reference speed data according to the following tests 5 17 1 1 Attended Operation 5 17 1 1 1 Nominal Displacement Distance for a Receding Vehicle Position the ATR device on the turntable c f figure 13 and aim the beam to within 0 1 of the nominal design angle specified by the manufacturer Activate the ATR device 6 1 04 Test Procedures Page 5 9 with its controls set for receding vehicles and its speed threshold feature turned off Once the ATR device has performed its self test routine activate the ATR test switch Drive the test automobile along the test path at a constant nominal speed of 32 km h 80 km hr and 112 km hr 20 mph 50 mph and 70 mph Record the readings of the ATR device and the reference speed meter as the test vehicle passes through the radar beam Repeat three times and verify that for each speed the average ATR device reading and the average reference reading agree with the requirements of 2 17 1 Repeat the procedure for the nominal design angle plus 1 and 1 or to the manufacturer s specified angle tolerance which ever is greater 5 17 1 1 2 Nominal Displacement Distance for an Approaching Vehicle Repeat the procedures of
28. evice shall not display any erroneous speed readings when an FM radio transceiver properly installed in the ATR device equipped vehicle is operating while the vehicle is standing still with the ATR device in the stationary mode with no other vehicle present 2 16 2 Handheld FM Transceiver Interference The ATR device shall not display any erroneous readings when a hand held FM transceiver with an integral antenna is operated inside the vehicle under similar circumstances 2 16 3 Citizens Band CB AM Transceiver Interference The ATR device shall not display any erroneous speed readings when a CB AM transceiver is transmitting while the ATR device equipped vehicle is stationary with no other vehicle present 2 16 4 Adjacent Vehicle Radio Frequency Interference 2 16 4 1 FM transceiver The ATR device shall not display any erroneous speed readings when a second vehicle with a transmitting FM transceiver is driven within 3 m 10 ft of the stationary vehicle while the ATR device is operating 2 16 4 2 CB AM transceiver The ATR device shall not display any erroneous speed readings when a second vehicle with a transmitting CB AM transceiver is driven within 3 m 10 ft of the stationary vehicle while the ATR device is operating 2 17 Speed Accuracy Field Operation The speed accuracy and the sensitivity of the ATR device to its physical alignment and distance from the target vehicle shall be evaluated in accordance with 5 17 and shall meet t
29. evices that meet or exceed these performance specifications Because this National Highway Traffic Safety Administration NHTSA document is designed as a development and procurement aid it is necessarily highly technical These performance specifications are subject to continuing review Technical comments and recommended revisions are welcome Please send suggestions to Enforcement and Justice Services Division National Highway Traffic Safety Administration 400 Seventh Street SW NTS 13 Washington DC 20590 Before citing these performance specifications or any part of them users should verify that the most recent edition of this document is being used NHTSA believes that these performance specifications for across the road radar speed measuring devices will assist law enforcement administrators in determining the accuracy and reliability of across the road radar devices they plan to purchase NHTSA also believes that these performance specifications and testing protocols will increase the confidence of law enforcement officers the public and the courts in the accuracy and reliability of across the road radar speed measuring devices 6 1 04 i 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module ACKNOWLEDGMENTS The National Highway Traffic Safety Administration wishes to express its appreciation to the following individuals that have contributed to the publication of this document A Geor
30. frequency response and a horizontal sweep time base resolution of 100 us cm or better It shall provide a reference voltage having an uncertainty of 5 or less for calibrating the vertical input 4 17 Reserved 4 18 Slide Whistle The slide whistle a wind instrument with a notched hollow tube and a variable displacement shall be capable of producing audio frequency notes from 500 Hz to 3 000 Hz 6 1 04 Test Equipment Page 4 3 4 19 Target Simulator 5 The target simulator diagrammed in figure 2 is designed to accept the unmodulated CW transmission from an ATR device under test and returns what appears to be the Doppler frequency modulated signal of a moving single scattering center The synthetic Doppler shift generated by the simulator shall be capable of simulating target speeds in the range of 32 km h 20 mph to 336 km h 210 mph accurate to within 0 16 km h 0 1 mph at all target speeds The carrier frequency and other sidebands produced by the simulator shall be suppressed by at least 20 dB The simulator shall also reproduce the downward or upward change in Doppler frequency caused by the cosine effect of an approaching or receding target passing through the radar beam and shall reproduce the duration of the radar return associated with different target lengths in the beam 4 20 Instrument Turntable The instrument turntable shall be capable of mounting and supporting the radar device in order to accurately rotate the uni
31. g exposure to a temperature of 30 C 22 F or the lowest temperature at which the manufacturer states that the ATR device will properly operate whichever is lower and following exposure to a temperature of 60 C 140 F or the highest temperature at which the manufacturer states that the unit will operate properly whichever is higher each ATR device shall continue to meet the requirements of 2 5 2 6 1 and 2 6 3 2 7 2 Operational Humidity Stability ATR device only When the ATR device is tested in accordance with 5 7 2 following exposure to 90 humidity at 37 C 99 F fora minimum of 8 h the equipment shall continue to meet the requirements of 2 5 2 6 1 and 2 6 3 2 8 Low Supply Voltage Indicator Each ATR device shall have a low voltage indicator that alerts the operator either visually or audibly when the supply voltage is reduced below threshold For an ATR device intended to operate from a nominal 12 V automotive system the low voltage indicator shall activate if the supply voltage is reduced to 10 8 V or to the lowest voltage Page 2 4 Requirements 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module specified by the manufacturer 2 2 5 whichever is lower For an ATR device utilizing a battery pack or other power supplies the low voltage indicator shall activate if the supply voltage is reduced to the lowest operating voltage specified by the manufacturer 2 2 5
32. ge Lieberman Ph D Program Manager Office of Law Enforcement Standards National Institute of Standards and Technology Richard R Larson Program Manager Radar Testing Program International Association of Chiefs of Police Members of the Enforcement Technologies Advisory Technical Subcommittee E T A T S Highway Safety Committee International Association of Chiefs of Police Appreciation is also extended to the manufacturers of across the road radar speed measuring devices for their cooperation in the preparation of this document 6 1 04 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module TABLE OF CONTENTS Page eelere DE i Acknowledgments EE iii Section 1 General Information SHI SCOPE an A Ee E 1 1 STEE geed A A A A 1 1 StS Applicat onr nne Anan A A E 1 1 1 4 Definitions EE 1 1 Section 2 Requirements 2 1 Manufacturer Provided Equipment sssssssssseenneeeseeeerrrnnnrnesserrrrrnnnneessee 2 1 2 2 Manufacturer Provided Information cccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeenaeees 2 1 2 3 Manufacturer Labeling EE 2 2 2 4 Tuning Fork Calibration ege Ceci dddegd eege 2 3 SZS Uning NEE 2 3 2 6 Microwave Transmission EEN 2 3 2 7 Environmental Extremes EES 2 4 2 8 Low Supply Voltage Indicator ee 2 4 2 9 Doppler Audie siiki i aiai a ee Ae ee 2 5 EE E 2 5 S2 POWE SUC EE 2 5 2 12 Speed BET EE 2 5 2 13 Signal Se e DEE 2 6 2 14 E EE 2 6 2 15 Co
33. he following requirements 2 17 1 Speed Accuracy When the ATR device is tested in accordance with 5 17 1 6 1 04 Requirements Page 2 7 speeds determined by the ATR device shall agree to within 2 km h 3 km h 01 times actual speed 1 mph 2 mph 01 times actual speed 2 17 2 Sensitivity to Distance When the ATR device is tested in accordance with 5 17 2 speeds measured by the ATR device shall satisfy the requirements of 2 17 1 for distances of 2 m to 10 m 6 ft to 33 ft between the radar device and the vehicle at its point of closest approach 2 18 Vehicle Determination Field Operation Speed Measurement Speeding violations shall be documented with a recorded image or images displaying the target vehicle in an appropriate position defined by the ATR device manufacturer The evidential image must show at a minimum the target vehicle s license plate speed location time and administrating officer s identification For comparison purposes the manufacturer shall provide sample images 2 18 1 Attended Operation The ability of the ATR device to discriminate between target vehicles shall be demonstrated using the field test methods described in 5 18 1 2 18 2 Unattended Operation If the ATR device is to be considered for unattended operation the manufacturer shall provide a secondary method for verifying that the evidential recorded image properly identifies the target vehicle and reflects this vehicle s
34. hever is higher Activate the operate switch on the ATR device and trigger the simulator Verify that the ATR device correctly displays the simulated speed Reverse the direction of simulated travel and repeat the test The ATR device shall again show the simulated speed 5 13 3 Reserved 5 13 4 Limiting Speed Test On the ATR device set the threshold speed control for an approaching automobile speed of 101 km h 63 mph Set the simulator speed to 104 km h 65 mph Activate the operate switch of the ATR device and trigger the speed simulator Verify that the ATR device displays a speed of 104 km h 65 mph and indicates a violation Repeat this with the threshold speed control set for an automobile speed of 107 km h 67 mph Verify that the ATR device displays a speed of 104 km h 65 mph but does not indicate a violation Reset the ATR device and simulator controls for a receding automobile and repeat the above tests Repeat the above for approaching and then receding trucks resetting both ATR device and simulator controls as appropriate 5 13 5 Reserved 5 13 6 Direction Sensing Test Set the ATR device to seek a receding automobile with the automobile threshold speed switch set to 101 km h 63 mph Reset the simulator controls for an automobile approaching at 104 km h 65 mph Activate the operate switch on the ATR device and trigger the simulator Verify that there is no indication of a speeding violation A reading of 00 error or a
35. ilizes an additional vehicle equipped with an FM transceiver and a CB AM transceiver This vehicle shall be driven at the speed of 48 km h 30 mph past the stationary ATR device so that at its closest approach the moving vehicle and the ATR device are separated by approximately 4 m 13 ft Activate the ATR device and using the FM transceiver repeat the procedure of 5 16 1 while observing the ATR device display for any erroneous readings Then using the CB transceiver repeat the test procedure of 5 16 3 again looking for erroneous readings 5 17 Speed Accuracy Field Operation If requested by the ATR device manufacturer test the unit for both attended and or unattended operation Install and connect the vendor supplied image recording equipment in accordance with instructions provided by the manufacturer Insure the antenna and image recording equipment are oriented for the direction of enforcement whether operating in the receding mode or approaching mode 5 17 1 Speed Accuracy Test Establish a measured distance of at least 800 m 2640 ft on an open level location away from other moving objects Clearly mark a path on this test track for the target vehicle to follow such that at its point of closest approach er figure 13 the target vehicle will be at least 4 m 13 ft from the ATR antenna Drive the test vehicle through this course and using the reference speed meter ascertain that the driver can safely maintain a constant spe
36. ity 10 8 V maximum automotive system or Few Supply volage as specified by the manufacturer battery 2 8 12 1 Microwave Frequency Display Readability Easily readable when used as intended 32 km h 20 mph maximum low speed Target Channel Speed Displays 160 km h 100 mph minimum high speed 2 13 2 2 km h 3 km h 01 times actual speed 1 Speed Accuracy mph 2 mph 01 times actual speed SE Vehicle Determination Documented with a recorded image or images 2 18 6 1 04 Appendix Page A 3 Speed Measuring Device Performance Specifications Across the Road Radar Module Test Diagram Not to Scale Microwave Monitored Target Beam Traffic Ly Sy Dy Centerline Lane Across the Road Radar ATR V Test Parameters Target Parameters 1 Ly Length m ft 2 Sy Speed km h mph 3 Dy Direction with respect to ATR device approaching or receding ATR DEVICE Parameters 1 BW Horizontal antenna beamwidth degrees 2 fo Microwave frequency MHz Setup Parameters 1 DA Design angle degrees 2 DD Displacement distance m ft Figure 1 Test parameters required for the ATR target simulator Page A 4 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module OPEN CIRCUIT COAXIAL STUB REFLECTIVE LOAD PYRAMIDAL 50 Q 0 141 COAX HORN MATCHING 5 TOTAL Z ANTENNA NETWORK r SWITCH UME OPEN CIRCUIT
37. k to 15 000 Hz verifying that no erroneous readings appear Pay particular attention to 15 750 Hz 5 15 3 Simulated FM Transceiver Interference Test 5 15 3 1 160 MHz According to figure 11 couple the signal of the FM generator into the power line of the ATR device using the line impedance stabilization network 6 1 04 Test Procedures Page 5 7 LISN of figure 12 Adjust the supply to provide standard voltage turn on the ATR device and as before establish a simulated target speed of 104 km h 65 mph 5 15 3 1 1 Vary Modulation Frequency Set the generator to an rf carrier frequency of 160 MHz with an output of 10 mW and no more than 1 mW of reflected power as indicated by the power meter Set the frequency deviation modulation width to 5 kHz and slowly vary the modulation frequency from 200 Hz to 10 kHz and back to 200 Hz in convenient steps Verify that no erroneous readings appear at any time on the ATR device display 5 15 3 1 2 Vary Output Power Repeat procedure 5 15 3 1 1 using a constant modulation frequency of 1 5 KHz while slowly varying the FM signal generator output from 0 mW to 10 mW and back to 0 mW Repeat the procedure again using a constant modulation frequency of 3 100 Hz 5 15 3 2 40 MHz Repeat procedure 5 15 3 1 for a 40 MHz carrier frequency 5 15 3 3 460 MHz Repeat procedure 5 15 3 1 for a 460 MHz carrier frequency 5 15 4 Simulated Citizens Band CB AM Transceiver Interference Test According to figure 1
38. ll be capable of producing 20 mW output power at frequencies from 30 MHz to 500 MHz and shall have an audio frequency modulation variation from 500 Hz to 5 000 Hz a 50 output impedance a maximum standing wave ratio of 1 2 and a variable output level It shall also have a deviation meter or calibrated control for determining the peak frequency deviation with an uncertainty no greater than 10 4 14 AM Signal Generator The AM signal generator shall cover the 25 MHz to 30 MHz frequency range be capable of producing at least 20 mW output power and 99 modulation with frequencies from 500 Hz to 5 000 Hz and have a 50 output impedance and a maximum standing wave ratio of 1 2 The generator should include a digital frequency counter having an uncertainty no greater than 1 part in 10 and an AM monitor or calibrated control for determining the AM percentage with an uncertainty no greater than 10 If an integral frequency counter is not included a separate frequency counter having the required accuracy shall be provided 4 15 RF Power Meter The rf power meter shall have 50 feed through detectors for frequencies from 20 MHz to 500 MHz and the ability to handle powers up to 50 W with an uncertainty of 10 or less 4 16 Oscilloscope The oscilloscope shall have a vertical input sensitivity y axis of 10 mV cm or better and a frequency response of at least 5 MHz It shall also have a horizontal input x axis having at least a 20 kHz
39. ncianebeltinnens 5 4 5 8 Low Supply Voltage AEN 5 4 5 9 Doppler Audio E 5 5 5 110 ROSCIVOG E 5 5 5 11 Power SUIS EE 5 5 5 12 Speed Display ENEE 5 5 5 13 Signal Processing DEE 5 6 5 14 Reserved eiae aiia aa tena E tad ceed aaa a aa Steed iaa a iaaa 5 7 5 15 Conducted Electromagnetic Interterence ee 5 7 5 16 Radiated Electromagnetic Interterence eeeeeeeeeeeeeeeeeeeneeeeeeeenneeees 5 8 5 17 Speed Accuracy Field Operation ceceesseeseeseesseeeesesseeseeesessceeeees 5 9 5 18 Vehicle Determination Field Operation DI Appendix Table 1 Speed Errors Due to Misahonment A 2 Table 2 Minimum Performance Specification for ATR Speed Measuring Devices sessseeseesnnrrttreeeerrrrrrnnnneseerrrrnnnneeeeeet A 3 Figure 1 Test parameters required for the ATR target simulator A 4 Figure 2 The ATR radar target simulator Il A 5 vi 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Figure 3 The tuning fork Calibration setup ssssssssssnrssessesrrrrrnnnessserrrrrrnn A 6 Figure 4 The transmission frequency and frequency stability measurements Sep eEgeERkEEKEERSEENNEEKCEEReEEKERKe EKEEEKeEENEEEKEEEENEEKeENd A 7 Figure 5 The input current and low supply voltage measurements setup A 8 Figure 6 The radiated output power stability measurement setup sss111 A 9 Figure 7 The antenna beamwidth measurement setup ssssss
40. nducted Electromagnetic Interterence 2 6 2 16 Radiated Electromagnetic Interference cccceceeceeeseeeeeeeeeeeeeeeeeeeeees 2 7 2 17 Speed Accuracy Field Operation EE 2 7 2 18 Vehicle Determination Field Operation Speed Measurement 2 8 Section 3 Test Conditions 3 1 Standard Test Conditions cise ei he he a eh ae A ee 3 1 Section 4 Test Equipment 4 1 Test Equipment EE 4 1 ET elel SY au 4 1 4 3 Microphone EE 4 1 4 4 Environmental Chamber 4 1 4 5 Anechoic Chamber dere reeche eege dee ee Seefe 4 1 6 1 04 4 6 Microwave Frequency Coumter 4 2 4 7 Field Strength Meier 4 2 54 8 ISOUODIC del 4 2 4 9 Line Impedance Stabilization Network LISN c eeeeeeeeeeeeeeeeeeeeeeees 4 2 4 10 Isolation Transtormmer 4 2 411 Pulse Generator ees 4 2 4 12 Sawtooth Wave Generator 4 2 4 13 FM Signal Generator EE 4 3 4 14 AM Signal Generator EE 4 3 4 15 RF Power GE 4 3 4 16 OSCO E 4 3 407 Reserved maipi i dee ee 4 3 ENEE 4 3 4219 Een ee LEE 4 4 4 20 Instrument JEE EE EE 4 4 4 21 Microwave Power Meier 4 4 4 22 Reference Speed Meier 4 4 Section 5 Test Procedures EE 5 1 ee E 5 1 5 3 Manufacturer Labeling ccceeseecceesesseeceeeeesseeeeesesseeneeesenseeseneeeescenenss 5 1 5 4 Tuning Fork Calibration EE 5 1 ER UE lte EE 5 2 5 6 Microwave ele TEE 5 2 5 7 Environmental EXtreM wcicidiscssutcioicantsiaccsaitinicratdienciantiaivinidiansi
41. ng horn antenna Radar antenna E Receiver or power meter BH _ angle of rotation Figure 7 The antenna beamwidth measurement setup Page A 10 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Standard A Figure 8 The antenna near field power density measurement setup 6 1 04 Appendix Page A 11 Speed Measuring Device Performance Specifications Across the Road Radar Module Standard supply voltage Isolation transformer Pulse generator Oscilloscope Manufacturer s power cable Figure 9 The simulated vehicle alternator interference measurement setup Page A 12 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Standard supply voltage Isolation transformer Sawtooth wave generator Oscilloscope Manufacturer s power cable Figure 10 The simulated vehicle ignition air conditioner heater and windshield wiper interference measurements setup 6 1 04 Appendix Page A 13 Speed Measuring Device Performance Specifications Across the Road Radar Module Standard supply voltage Manufacturer s power cable AM or FM signal generator Power detector Figure 11 The simulated police FM transceiver and the citizens band AM transceiver interference measurements setup Page A 14 Appendix 6 1 04 Speed Measuring Device Perfo
42. nitor the signals reflected from the moving vehicles crossing the microwave beam process the Doppler shifts of the reflected signals for the vehicle speeds and may automatically record images of those vehicles which exceed a preset speed 1 4 Definitions The principal terms used in this document are defined in this section Additional definitions relating to law enforcement electronic items may be found in reference 2 1 4 1 Accuracy the degree to which a radar device measures and displays the correct speed of a target vehicle 1 4 2 Acquired Target a vehicle which enters the radar beam of an ATR device allowing for a measurement of its speed 1 4 3 Across the Road Radar ATR Device a radar device which operates at a specified angle to the path of vehicle s and which makes allowance for the cosine angle effect 1 4 4 Ambient Interference The conducted and or radiated electromagnetic interference and or mechanical motion interference at a specific test location and time which might be detrimental to proper radar device performance 1 4 5 Antenna Horizontal Beamwidth the total included acute angle in the horizontal plane of the main lobe between the half power points of the radar antenna far field radiation pattern where the half power points are measured relative to the maximum power at the center of the radar beam and on a radius equidistant from the face of the antenna 6 1 04 General Information Page 1 1 1 4
43. ntenna Beamwidth The full beamwidth between half power points in the horizontal plane shall not exceed 12 for X band or 6 for K band and Ka band ATR device At angles offset from the direction of maximum radiation and exceeding 13 for X band and 11 for K band and Ka band ATR device the radiated far field power shall remain at least 20 dB below that of the maximum For all ATR devices the total included angle between the half power points in the vertical plane of the primary radar beam shall be no greater than 20 The sidelobe power radiated in any direction shall be 15 dB below the maximum value of the main lobe In addition the primary radar beam shall be centered horizontally at the design angle specified by the manufacturer 0 5 and vertically at 90 0 5 2 6 5 Antenna Near Field Power Density The maximum antenna near field power density of each ATR device shall not exceed 5 mW cm 2 6 6 Standby Operate Switch When so equipped no rf power shall be transmitted unless the standby operate switch is closed Transmission shall commence without delay when the switch is closed and immediately cease when the switch is opened 2 7 Environmental Extremes The ability of the ATR device to operate in environmental extremes shall be determined using the test methods described in 5 7 and shall meet the following requirements 2 7 1 Operational Temperature Stability ATR device only When tested in accordance with 5 7 1 followin
44. ode with a threshold speed of 35 mph Drive an automobile at 50 mph through the radar beam in the approaching direction Repeat but drive the automobile in the opposite direction through the ATR device beam The ATR device shall only record the image of the approaching automobile 5 18 1 1 2 Receding Mode Repeat the test with the ATR device in the receding mode The ATR device shall only record the image of the receding vehicle 5 18 1 2 Speed Discrimination 5 18 1 2 1 Approaching Mode Place the ATR device in the approaching Page 5 10 Test Procedures 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module mode with a threshold speed of 65 mph Drive an automobile at 50 mph through the radar beam in the approaching direction The ATR device shall not record the image of the automobile Repeat this test a second time 5 18 1 2 2 Receding Mode Repeat the test with the ATR device in the receding mode The ATR device shall not record the image of the receding vehicle Repeat this test a second time 5 18 1 3 Multiple Vehicles 5 18 1 3 1 Approaching Mode Place the ATR device in the approaching mode with a threshold speed of 50 mph Drive two automobiles at any speed slower than the threshold speed so that they are operating in different lanes and pass through the radar beam simultaneously The ATR device shall not record the images of any automobile 5 18 1 3 2 Receding Mode Repeat the test with the ATR
45. oltage Indicator a sensing circuit of the radar device which alerts the operator that a low supply voltage condition exists which may affect radar performance 1 4 19 Microwave Output Power the power produced by the microwave transmitter that is delivered to the input of the radar antenna 1 4 20 Near field Region the region in close proximity to the transmitting antenna that is not included in the region defined as far field region 1 4 21 Nominal Value the numerical value of a device characteristic as specified by the manufacturer 1 4 22 Polarization the property of a radiated electromagnetic wave describing the time varying direction and magnitude of the electric field vector 1 4 23 Power Density the amount of microwave power passing through a unit area of space measured in a plane that is perpendicular to the direction of propagation 1 4 24 Recorded Image images recorded on photographs microphotographs electronic images videotape or any other medium 1 4 25 Sidelobes radar beams from the antenna which are not part of the primary radar beam but which may appear as shoulders on the primary radar beam 1 4 26 Simulator a device that generates a precisely defined synthetic Doppler reflection for testing radar devices 1 4 27 Squelch the capacity of a radar device to inhibit the Doppler audio sound when the radar is in operation and not receiving a target signal 1 4 28 Tuning Fork an electronic or mechani
46. only correct readings are displayed 6 1 04 Test Procedures Page 5 5 5 13 Signal Processing For each of the following tests the simulator should be positioned facing the ATR antenna directly in line with the center of the radar beam The ATR device and simulator should be warmed up and the ATR device should complete its self test routine before going further Tests shall be completed for all vehicle types at minimum and maximum displacement distances 5 13 1 Speed Accuracy Test Set the ATR device controls to seek an approaching vehicle Turn on the simulator and set its controls to simulate the Doppler signature from a vehicle approaching at 104 km h 65 mph Activate the ATR device and trigger the speed simulator Verify that the ATR device displays the simulated speed Repeat for a receding vehicle 5 13 2 Minimum and Maximum Speed Test Set the ATR device to respond to the vehicles of arbitrary size traveling in either direction Set the simulator for an approaching vehicle having a speed of 32 km h 20 mph Activate the operate switch on the ATR device and trigger the simulator Verify that the ATR device correctly displays the simulated speed Reverse the direction of simulated travel and repeat the test The ATR device shall again show the simulated speed Repeat with the simulator set for an approaching vehicle having a speed of 160 km h 100 mph or the highest speed the manufacturer states that the unit will properly operate whic
47. onnect the test equipment as shown in figure 6 Mount the isotropic probe of the field intensity meter 50 cm to 100 cm 20 in to 40 in above the radar antenna and within the primary radar beam Adjust either the ATR device or the probe horizontally to maximize the probe reading Record the distance between the antenna aperture and the isotropic probe adjust the supply voltage to its standard value and record the field strength of the microwave output signal Vary the supply voltage 20 and record the change in microwave output power density 5 6 4 Antenna Beamwidth Test Place the ATR antenna on an antenna positioning device capable of rotational resolution of 0 1 in the anechoic chamber or above an open ground plane with absorbing materials placed on the ground surface to disperse Page 5 2 Test Procedures 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module the reflected signal Position the ATR antenna at least 2 m 6 6 ft from any surface that may interfere with the pattern being measured and in the same posture as actually used Place a small receiving antenna preferably a small standard high efficiency horn at a distance from the ATR antenna such that its direction of polarization is the same as the ATR antenna Connect a power meter or receiver to the receiving antenna depending on the strength of the radiated field Adjust the distance between the two antennas such that the receiver apert
48. ordance with 5 13 4 the ATR device shall register a violation for vehicle speeds above an adjustable threshold but not for slower vehicle speeds 2 13 5 Reserved 2 13 6 Direction Sensing When tested in accordance with 5 13 6 the ATR device shall be able to sense the direction of travel of a passing vehicle and to reject the signals of vehicles traveling in the undesired direction 2 14 Reserved 2 15 Conducted Electromagnetic Interference Unless the ATR device is independently powered from dedicated batteries which remain isolated from their recharging system during traffic enforcement the susceptibility of the ATR device to simulated electromagnetic interference from the vehicle alternator vehicle ignition air conditioner neater motor windshield wiper motor and typical police and citizens band transceivers shall be evaluated as follows During these tests a blank target speed display shall not be considered an erroneous reading 2 15 1 Simulated Vehicle Alternator Interference When subjected to a 10 us to 20 us wide pulse signal of 1 V p p amplitude except for transition spikes having a maximum rise time of 2 us and a maximum fall time of 2 us both excluding ringing and having a ringing time no greater than 8 us with a pulse repetition rate between 200 pulses per second pps and 10 000 pps the ATR device shall not display any erroneous readings 2 15 2 Simulated Vehicle Ignition Air Conditioner Heater Motor and Windshield
49. orthogonal dipoles enclosed in a 10 cm 4 in diameter protective sphere a minimum detectable power density level of 0 01 mW cm over the frequency range from 10 000 MHz to 40 000 MHz and high resistance between the sensor and metering units 4 9 Line lmpedance Stabilization Network LISN 4 The line impedance stabilization network LISN constructed as in figure 12 with shielded terminals shall be capable of simultaneously interfacing with the radar device the standard supply voltage source and the interference injection generator 4 10 Isolation Transformer The isolation transformer shall have a 4 1 impedance ratio a frequency range of 30 Hz to 16 000 Hz and the secondary winding as connected shall be capable of handling the current flow without saturating the core 4 11 Pulse Generator The pulse generator shall be capable of producing 20 V p p across a 50 Q output impedance with rise and fall times of less than 1 us and pulse repetition rates to 200 pps to 10 000 pps 4 12 Sawtooth Wave Generator The sawtooth wave generator shall be capable of producing 20 V p p across a 50 Q impedance It shall also be capable of producing a sawtooth wave having a positive going leading edge with less than 1 us rise time over a frequency range of 200 Hz to 16 000 Hz Page 4 2 Test Equipment 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module 4 13 FM Signal Generator The FM signal generator sha
50. rmance Specifications Across the Road Radar Module Shielded terminal Shielded terminal to radar device to power l l RF connector m to 50 Q impedance Ground terminal Ground terminal Metal case shield Figure 12 The line impedance stabilization network LISN 6 1 04 Appendix Page A 15 Speed Measuring Device Performance Specifications Across the Road Radar Module Test Vehicle velocity v eng Bag EE DR RER ee Radar Antenna 7 ft fa eee 4 Lane D i 7 Design m Marker Angle Turntable Figure 13 The operational speed accuracy measurements setup shown for receding traffic Page A 16 Appendix 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module BIBLIOGRAPHY 1 NHTSA Technical Report DOT HS 808 069 Model Minimum Performance Specifications for Police Traffic Radar Devices 1994 January 2 Greene F M Technical Terms and Definitions Used With Law Enforcement Communications Equipment LESP RPT 0203 00 National Institute of Justice U S Department of Justice Washington DC 20531 1973 July 3 Jasik H R Antenna Engineering Handbook New York NY McGraw Hill 1961 4 SAE Recommended Practice J1113A Electromagnetic Susceptibility Procedures for Vehicle Components 1987 August 5 Ondrejka Arthur R and Johnk Robert T A Portable Calibrator for Across the Road Radar Systems NIST Tech Note 1398 1998 May 6 1 04 Bibliography
51. sessssssssssrrerren A 10 Figure 8 The antenna near field power density measurement setup A 11 Figure 9 The simulated vehicle alternator interference Measurement SetUP eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees A 12 Figure 10 The simulated vehicle ignition air conditioner heater and windshield wiper interference measurements Setup A 13 Figure 11 The simulated police FM transceiver and the citizens band AM transceiver interference measurements Setup A 14 Figure 12 The line interference stabilization network IN A 15 Figure 13 The operational speed accuracy measurements setup shown for receding rafe A 16 Bibliography 6 1 04 vii Speed Measuring Device Performance Specifications Across the Road Radar Module Section 1 General Information 1 1 Scope The scope of this document is limited to automated across the road radar systems used by law enforcement agencies for enforcing vehicle speed regulations 1 2 Purpose The purpose of this document is to specify minimum performance requirements and methods of test for the stationary automated across the road radar devices used by law enforcement agencies to measure display and record images of vehicles moving at excessive speeds along the nation s roads and highways 1 3 Applications This document applies to radar speed measuring devices that transmit an unmodulated continuous wave CW microwave beam across the roadway mo
52. st Conditions Page 3 1 Speed Measuring Device Performance Specifications Across the Road Radar Module Section 4 Test Equipment 4 1 Test Equipment The test equipment discussed in this section is limited to that equipment which is most critical in making the measurements discussed in this document All other test equipment shall be of laboratory instrumentation quality 4 2 Multifunction Synthesizer The audio frequency multifunction synthesizer shall be capable of providing a sine or square wave voltage of at least 10 V p p across a 50 Q load with an offset of 5 V dc over a frequency range of 200 Hz to 100 kHz It shall sweep upward or downward from the starting programmed frequency to the stopping programmed frequency at a sweep rate such that the sweep duration is adjustable from 0 1 s to 2 s The synthesizer shall be capable of a single sweep by manual control or external trigger and repetitive sweeps adjustable from 0 1 s to 5 s The audio output shall only be present during the frequency sweep The synthesizer should also be capable of producing a continuous single frequency sine or square wave The frequency output accuracy shall be derived from a time base of at least 50 parts per million or better accuracy 4 3 Microphone The microphone shall have a frequency range of 300 Hz to 10 kHz and shall be capable of coupling tuning fork tones into an amplifier or oscilloscope 4 4 Environmental Chamber The environmental cham
53. t in the horizontal plane It shall provide major scale divisions of at least 0 1 resolution and be small enough to fit into the ATR device vehicle for operational tests A vernier scale readout is permissible for resolutions greater than 0 1 4 21 Microwave Power Meter The microwave power meter shall be used as a signal receiver for the antenna beamwidth measurements It shall have power sensors capable of detecting microwave signals down to at least 30 dB and a dynamic range of at least 40 dB at microwave frequencies up to 36 000 MHz 4 22 Reference Speed Meter The reference speed meter possibly a fifth wheel or other precision mechanical electrical or optical soeed measuring device that is capable of measuring instantaneous vehicle speeds to an accuracy of at least 0 3 km h 0 2 mph Page 4 4 Test Equipment 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module Section 5 Test Procedures 5 1 Reserved 5 2 Reserved 5 3 Manufacturer Labeling 5 3 1 ATR Device Labeling The ATR device shall be examined to verify that the controls operate as explained in the user s manual and are consistent with their markings for this purpose The simulator or normal traffic may be used to input data It is permitted for controls to have secondary functions beyond those marked in these cases there is a particular obligation for the manual to be written in plain English and to describe the use of the controls
54. ure subtends an angle of roughly 1 0 with respect to the ATR antenna in the plane of rotation as shown in figure 7 For example a receiving antenna with a horizontal aperture dimension of 3 cm 1 2 in shall be located about 2 m 6 6 ft from the transmitter Turn on the power and allow the equipment to stabilize Rotate the ATR antenna so that the receiving antenna is close to the center of the transmitted radar beam and then measure the output from the receiver using the power meter Adjust the receiving antenna until the power meter can measure down over a 25 dB range If the signal is too small for the power meter replace it with a receiver or spectrum analyzer capable of detecting the signal Rotate the ATR antenna to maximize the coupling with the receiver antenna Determine that the received signal strength is within the measurement range of the measuring device below the maximum signal capability and at least 30 dB above the minimum capability Rotate the ATR antenna counterclockwise until a line from the ATR antenna to the receiver antenna is exactly parallel to the plane of the ATR antenna aperture This shall be defined to be the pattern angle of 0 Measure and record the received power Rotate the ATR antenna clockwise and repeat the measurement at angular increments of 1 Whenever the received power is larger than 20 dB of the maximum the rotation shall be reduced to 0 5 per step This shall continue through the main lobe of the ra
55. vate the ATR device Set the ATR controls for detection of vehicles of arbitrary speed length and direction With no other vehicle present activate the transceiver push to talk switch and use the slide whistle to transmit tones via the microphone Vary the tone of the slide whistle from 500 Hz to 3 000 Hz and back to 500 Hz while observing the ATR speed display for possible erroneous readings Page 5 8 Test Procedures 6 1 04 Speed Measuring Device Performance Specifications Across the Road Radar Module 5 16 2 Hand Held Transceiver Interference Test Turn off the FM transceiver and repeat the previous test procedure using a handheld FM transceiver having an integral antenna an output power of 2 W or more and positioned at the driver s location 5 16 3 Citizen s Band CB AM Transceiver Interference Test For this test a CB transceiver having at least 4 W output power shall be operated from a front seat location its antenna shall be mounted on the exterior of the vehicle as recommended by the radio manufacturer The CB transceiver shall draw its power from the vehicle battery Start the patrol vehicle engine and set it to a fast idle with the heater and air conditioner turned off Switch on the CB transceiver and tune it to channel 20 Follow the procedure used in the two previous interference tests Repeat the procedure for CB channel 1 and then for CB channel 40 5 16 4 Adjacent Vehicle Radio Frequency Interference Test This test ut
56. ver is lower and the pulse repetition rate to 200 pps with a pulse width of 10 us to 20 us Maintain the simulator speed at 104 km h 65 mph while slowly varying the generator frequency from 200 pps to 10 000 pps and back to 200 pps in convenient steps Verify that no erroneous speed readings appear at any time on the ATR device display 5 15 1 2 Amplitude Dependence Repeat this procedure but now fix the pulse repetition rate at 1 500 pps Slowly vary the pulse amplitude from O V to 1 V p p or 7 5 of the standard supply voltage whichever is lower and back to 0 V as monitored on the oscilloscope Repeat this procedure using a constant pulse repetition rate of 3 100 pps 5 15 2 Simulated Vehicle Ignition Air Conditioner Heater Motor and Windshield Wiper Motor Interference Test Disconnect the pulse generator from the isolation transformer and replace it with the sawtooth wave generator as shown in figure 10 Using the oscilloscope to monitor the waveform set the generator frequency to 200 Hz and the signal output to 1 V p p or 7 5 of the standard supply voltage whichever is lower Maintain the simulator speed at 104 km h 65 mph while slowly varying the sawtooth frequency from 200 Hz to 10 kHz and back to 200 Hz in convenient steps Verify that no erroneous readings appear at any time on the ATR display For Ka band ATR device repeat this procedure while slowly varying the sawtooth generator frequency from 15 000 Hz to 16 000 Hz and bac
57. with the flat side parallel to the direction of propagation The ATR device must display the speed corresponding to the tuning fork frequency corrected for cosine angle effect within the allowable tolerance 5 5 2 Electronic Tuning Fork For an ATR device responding to an electronic tuning fork follow the manufacturer s directions for checking the operation of the ATR device speed processing function The ATR device must display the speed specified by the manufacturer within the allowable tolerance 5 6 Microwave Transmission 5 6 1 Transmission Frequency and Frequency Stability Test Place the ATR device in the anechoic chamber if available and connect the test equipment as shown in figure 4 Position the pickup antenna in the radar beam a sufficient distance away from the ATR device to prevent overdriving the microwave frequency counter Adjust the supply voltage to its standard value allow it to stabilize for 2 min and then record the microwave frequency Reduce the supply voltage by 20 of its standard value or to the manufacturer s low voltage value whichever is lower and wait 2 min and record the microwave frequency Increase the supply voltage by 20 of its standard value or the manufacturer s high voltage value whichever is higher and wait 2 min and record the microwave frequency 5 6 2 Reserved 5 6 3 Radiated Output Power Stability Test Position the ATR device on a vertical test stand with the antenna pointed upward and c

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