lidar

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lidar
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  1. Setting Up Procedures - Silver Eagle Mobile Radar
    • Assembly
    • 1. Mount the antenna in accordance with the instructions for antenna placement and aim.
    • 2. With the power off, insert the multi pin (7) pin plug terminating the antenna cable into the corresponding receptacle on the rear panel of the counting unit.
    • 3. Connect counting unit to remote display with interface cable
    • 4. Insert the remote control phone jack into the remote control receptacle on the rear panel of the counting unit.
    • 5. Insert the power cable plug into the two-pin receptacle of the vehicle’s shielded power supply.
    • 6. Place the remote display for convenient viewing by the operator (remember the safety factor).
    • Testing Procedure
    • 1. Visually check correct antenna placement and alignment.
    • 2. Press power switch on. Check that the direction antenna - mode indicators are illuminated. The radar will process through a test to ensure all segments and indicators illuminate, an internal test (crystal check), and current audio and range settings are displayed sequentially.
    • 3. Press and hold the test switch. All indicators and segments will illuminate. Release the test switch and "PAS" will appear in patrol and target displays (whilst in moving mode). In stationary mode "PAS" appears only in the target display.
    • 4. Press the audio button and a number between zero and nine indicating the current audio level is shown in the patrol display. Pressing the range (up) or audio (down) adjusts volume.
    • 5. Press the range switch and a number between one and six indicating the present range setting is shown in the patrol display. Range is adjusted by pressing the range button (increase) or audio switch (decrease).
    • 6. Select stationary mode by pressing the mode switch and carry out tuning fork tests using both "45" and "80" km/h tuning forks.
    • 7. Select moving mode by pressing the mode switch carry out moving mode tuning fork test using both forks simultaneously. Observe "45" in patrol display and "35" in the target display.
    • 8. Commence patrol - correlate patrol speed with checked speedometer to ensure correct antenna alignment.
    • 9. Select hold and continue patrol.
    • 10. Perform internal calibration test (as described in point two above) at hourly intervals.
    • 11. At the completion of duty repeat steps 3 to 7.
  2. How often during a shift should the testing procedures be carried out?
    • 1. Before speed enforcement commencers.
    • 2. Once every hour durring speed enforement.
    • 3. At the completion of speed enforcement.
  3. List the test procedures to be carried out on an hourly basis?
    Momentarily depress the test switch. Holding the test switch depressed will light all displays. Upon releasing this switch, the Silver Eagle II will complete the internal test. If these tests pass, the target window will display "PAS" in the Target window. If the test switch is held depressed for greater than 10 seconds, the internal test will proceed as a default condition.
  4. List the effects you have observed whilst operating the radar. Include the circumstances and possible cause/s of the effect.
    • Natural Interference
    • Natural interference basically reflects and diffuses (scatters) the radar energy. Large trees, bushes and signs moved by the wind, heavy rain or snow, windblown dust, in fact any particulate matter in the air will tend to diffuse the radar・s energy or mask low-level signals, resulting in a decrease in effective range.
    • Heavy Rain
    • It has been found from wide experience that heavy, driven rain falling non-perpendicular to the roadway can add to or subtract from correct patrol speed depending upon the relative direction of the radar. This problem is avoided by adherence to the operational guidelines. Fog, light rain or drizzle will cause some reduction in effective range but will not affect accuracy.
    • Man‑Made Interference
    • Man-made interference is by far the most troublesome and constitutes the largest category. Large advertising signs if rotating or swinging may reflect the beam. Large broad-bladed fans may also reflect sufficient energy to cause a speed reading. Electronic emissions from fluorescent lights, power transformers, x-ray and medical diathermy machines, high voltage transmission lines with leaky insulators, radio transmitters, mobile phones, automobile inverters, etc., may, in some circumstances, cause a speed reading or a reduction in effective range.
    • Shielded Cable
    • Interference from a vehicle’s electrical system can enter the radar through the connecting cables. To overcome this, all Highway Patrol cars are fitted with shielded cable to ground any spurious emissions and thus negate the adverse effects of electrical interference. Other vehicles are not normally fitted with shielded cable therefore radar cannot be operated from those vehicles.
    • Radio Frequency Interference
    • Under normal operating conditions the presence of Radio Frequency Interference should not be a cause for concern by the operator. The Silver Eagle II radar has an RF detector which, when activated by excessive RFI, causes the displays to blank. This is an automatic feature of the system and is beyond the control of the operator. On the front panel, indication of RFI presence is given in the form of ‘rfi’ being displayed in the Target window of the Radar. There is no need for any action to be taken by the operator - the instrument will return to normal operation once it is no longer being interfered with.
    • Effect of Radar Detectors
    • After stopping a motorist with an early warning device (radar detector) fitted to their vehicle, operators may find that a speed reading appears in the absence of a target. For this to occur the detector must be within 3 metres of the antenna and directly facing it. Although it may be considered interference to radar operation, it is merely a display brought about by the modulation of the beam by the early warning device. The radar instrument cannot be affected by the detector during the speed check.
    • Multipath Interference
    • This phenomenon is likely to occur on long straight roads where Armco railing and similar barriers are used. As the name implies, it is the arrival of two energies at different time intervals at the receiver. Refer to figure 4.1. E2 arrives at the receiver earlier than E1 due to the shorter distance it needs to travel. On arrival at the receiver E1 and E2 oppose one another, often resulting in cancellation of both. This phenomenon causes short ‘blips’ in the audible tone and only occurs for very short periods (maximum duration about 1 second). Multipath does NOT affect the accuracy of any speed reading.
  5. What are the requirements for a valid speed check?
    • 1. Visual observation and estimation of the target’s speed.
    • 2. Observe the numerals in the patrol and target displays.
    • 3. Clear, constant (if appropriate) tone.
    • 4. Correlation between patrol speed and checked speedometer.
    • 5. Duration of the check (steps two, three and four) must not be less than three seconds.
    • 6. Minimum of 200 metres between targets of similar size.
  6. List the buttons found on the remote control handset and describe the function of each button.
    • (A) Lock/Release - performs identical functions as lock release on the remote display counting unit
    • (B) Front Hold - hold button for front antenna port.
    • (C) Fastest vehicle – (Disabled)
    • (D) Rear Hold - hold button for rear antenna port.
    • (E) Patrol Select - pressing the switch displays the current minimum patrol speed setting.
  7. What must be considered when selecting a stationary site?
    So that there will be no misunderstanding as to the responsibilities of police engaged in the operation of radar/lidar instruments, the following requirements concerning the location and operation of such units should be borne in mind. They are not to be used:

    • 1. Within 50 metres of a speed restriction or de-restriction sign creating a change to the speed zone being enforced unless;*
    • —— Speed is excessive (e.g. at least in excess of 20 km/h of the zoned speed limit);or
    • —— subject of complaint; or
    • —— where there is a high accident history;
    • * this does not apply to school zones.
    • 2. At any location or deploy a vehicle that would engender legitimate criticism or give rise to the complaint that they are a means of raising Government revenue.

    When operating speed measuring instruments police should be aware of Australian Design Rules pertaining to motor vehicle speedometers.
  8. Testing Procedures - Lidar

    The distance accuracy check is carried out over what distances?
    • 1. Check the range at the 25m mark and note the distance shown in the HUD.
    • 2. Check the range at the 50m mark and note the distance shown in the HUD.

    • (Measurement accuracy must be within ± 200mm or 0.2 metre), If the measurements are not within
    • the required accuracy specifications the Lidar should be returned to the Radar Engineering Unit
    • for service.
  9. Describe in your own words the HUD alignment check?
    • 1. Aim the ProLaser at a pole or small sign with a clear background.
    • 2. Verify the volume is audible.
    • 3. Slowly move the ProLaser from left to right and back. When the HUD reticle is off
    • the target, no tone should be heard and the range display should be blank.
    • 4. As the HUD reticle is slowly moved onto the target, a staccato (or chirp) aiming
    • tone should be heard until the aiming reticle is no longer on the target. The
    • ProLaser will also indicate the range or distance to the target. This indicates that
    • the ProLaser beam is focused at the same point as the aiming reticle.
    • 5. Place the ProLaser on its side (rotate 90 degrees) and retest. This will verify that the
    • beam is both vertically and horizontally aligned with the aiming reticle.
  10. When the lidar instrument is turned on what is displayed in the HUD and in the rear displays? What do the displays mean?
    • Power Up
    • Turn on the power supply switch and verify the LCD displays the self-test sequence.
    • Self Test Messages
    • Upon power up of the unit or a user-initiated self-test, the unit will run self-test. This test
    • consists of the following test messages in the rear display.
    • Internal/External Memory Tests
    • Performs a check of the contents of the memory chips in which the microprocessor
    • programs reside.
    • Programmable Options Test
    • Checks for corruption of the units configuration memory.
    • Accuracy Test
    • Performs a comparison between two independent timing circuits to verify that the range
    • and speed determination circuits are operating properly.
    • Program Memory Test
    • Checks the units programmable memory for validity.
    • Indicates unit self-test is complete.
  11. What must be considered when selecting a site for the operation of Lidar?
    • There are several factors to be taken into account when selecting a site for the ProLaser III such as:
    • 1. cosine angle;
    • The position of the ProLaser III in relation to the roadway (cosine angle effect) is identical
    • to radar. Remember, the cosine effect is a fact of physics and cannot be corrected by the
    • operator except by standing on the edge of the roadway.

    • If the operator is standing 6m from the centre of the roadway and the vehicle is 50m away,
    • the angle or cosine effect would be less than 2kph. Any cosine angle error will always be
    • in the driver’s favour.
    • 2. clear line of sight;
    • Having a clear line of sight to the target vehicle is mandatory. Items such as power pole
    • guy wires, radio antennas on passing vehicles, fences, tree branches and other objects will
    • interfere with the ProLaser III. Remember, the ProLaser III takes over 200 readings per
    • second and the best least squares fit requires the data fall into a normal return for the
    • speed of the vehicle. If there is an object between the ProLaser III and the targeted vehicle,
    • the large variation in distance returns will cause the computer to disregard, and all data
    • and no speed readings will be displayed.
    • 3. weather conditions; and
    • Weather conditions play a major role in the maximum target acquisition distance. Fog,
    • snow, rain and blowing dust can all interfere with the ability of the ProLaser III to obtain
    • a speed reading on a target vehicle. While no spurious or ghost speed readings will be
    • displayed during these conditions, the range to a target vehicle will be reduced.
    • 4. movement of the unit.
    • Of all the various external effects on the ProLaser III, operator motion or jitter while
    • targeting a vehicle will have the most effect. Because the least squares looks for a straight
    • line fit, any additional motion by the operator such as hand motion, motion caused by
    • wind or motion caused when the operator is attempting to track a target vehicle at a large
    • cosine angle, may cause the ProLaser III to fail to display any speed reading until the unit
    • is stabilised.
    • By holding the trigger depressed on the ProLaser III, the operator can continue to update
    • the displays four times per second as long as enough data is being received to satisfy the
    • least squares fit. If the ProLaser III is not receiving enough valid data, the existing HUD
    • and read panel displays will blink to tell the operator that no additional speed updates will
    • be made until the minimum data returns have been satisfied. The audio aiming tone will
    • change from the solid tone to the staccato tone to also alert the operator that they need to
    • remain, steady, or eliminate any interference.
  12. What information is visible in the HUD during a speed check of a target vehicle?
  13. Speed Range
  14. Outline the information that needs to be given to stop crews at distant stopping locations.
  15. When carrying out lidar operations using a distant stopping location, as the operator, what information do you need to record for future reference (court, complaints) and how is that information recorded?
  16. Identify the buttons on the back of the lidar instrument and outline the function of each button.
  17. In your own words explain how to change the lidar instrument from range mode to speed mode.

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