1
Q
- What does RADAR stand for?
A
Radio Detection and Ranging.
2
Q
- What type of energy is transmitted by the Silver Eagle III radar?*
A
It is a continuous wave of Electromagnetic Energy
3
Q
- What is the transmitted frequency of the Silver Eagle III radar?*
A
34.9 GHz (speed of light).
4
Q
- What is the size of the wave length transmitted from the Silver Eagle III radar?*
A
8.59 millimetres.
5
Q
- What is the spread/width of the Silver Eagle III radar?
A
The radar beam leaves the antenna and spreads out at an angle of 12 degrees (plus or minus 1 degree). For every 100 metres the spread of the beam is 21 metres.
6
Q
- What is the operating voltage of the Silver Eagle III radar?*
A
9.0 to 16.5 volts
7
Q
- What does ‘Lo’ mean when it appears on the radar instrument?
A
‘Lo’ will appear in the target speed display window when the power supply voltage drops below the minimum operating voltage.
8
Q
- What is the operating temperature of the Silver Eagle III radar?
A
-30 degrees Celsius to +60 degrees Celsius.
9
Q
- What is the target speed range of the Silver Eagle III radar? *
A
Generally, 16 Km/h to 330Km/h.
10
Q
- What is the patrol speed of the Silver Eagle III radar? *
A
Generally 16 Km/h to 160 Km/h.
Combined and Patrol speed will not exceed 330km/h.
11
Q
- Why is reflection important to the operation of the Silver Eagle III radar?
A
Because the Silver radar relies on energy being reflected from the target (echo) to operate.
12
Q
- What is Doppler Tone? *
A
Doppler Tone is the Doppler Shift Frequency (Fd) divided down by 6 (for Stationary) or 12 (for mobile) for listening comfort.
13
Q
- What is the importance of a clear tone during a valid speed check?
A
A clear tone indicates the radar is monitoring only one target and is not being subjected to any interference. Any change in pitch must be accompanied by evidence of altering speed.
14
Q
- What is Doppler Shift? *
A
It is the actual difference (change) between the transmitted and received frequencies.
Caused by relative velocity
15
Q
- What test does the operator perform to check for segment faults in the displays of the Silver Eagle III radar?
A
An Internal Calibration Test. Press and hold the test button to observe that all the LEDs and segments are illuminated.
16
Q
- How does interference commonly affect the Silver Eagle III radar?
A
It displays a speed in the absence of a target or it does not display a speed when a target is present.
17
Q
- What happens to the Silver Eagle III radar when subjected to radio frequency interference (RFI)?
A
Radio Frequency detector is activated and causes the displays to blank and ‘rFi’ will be displayed in the target window of the radar.
18
Q
- Explain inverse square law? *
A
The amount of energy returned to the radar from a target depends on:
1. The reflective area of the target (target size).
2. Distance between the radar antenna and the target.
19
Q
- Is the Silver Eagle III radar capable of registering the speed of a motor cycle when a truck is in sight? Explain.
A
It is possible to register a speed however the radar obeys inverse square law. Therefore, the truck having a larger reflective surface than a motor cycle, would reflect more energy at a greater distance. The motor cycle would have to be much closer than the truck for the radar to register the speed of the motor cycle.
20
Q
- Why is it important to correlate the patrol speed with the checked speedometer during speed checks? *
A
During Setup: To ensure correct antenna alignment.
During Speed Check: To ensure the radar is not subjected to any interference or effect.
21
Q
- Name 4 types of interference and explain how each affects the radar beam?
A
- Natural Interference – Causes a decrease in effective range of the radar.
- Heavy Rain – Heavy, driven rain falling as a significant angel to the roadway can add to or subtract from correct patrol speed and may cause some reduction in effective range.
- Man-Made Interference – Causes a speed reading or a reduction in effective range.
- Electrical Interference – Shielded cables are used to negate adverse effects of electrical interference.
22
Q
- Name examples of Natural Interference:
A
- Large trees
- Bushes
- Heavy rain
- Falling snow
- Windblown dust
23
Q
- Name examples of Man-Made Interference:
A
- Large advertising signs
- Bridges
- X-ray
- Radio transmitters
- Mobile phones
24
Q
- What is the length of the radar beam?
A
The length of the beam is infinite but the effective length is nominally 600 metres.
25
25. What is Multipath Interference? *
Multipath Interference is 2 energies arriving to the receiver at different time intervals. It causes short blips in the audible tone and only occurs for very short periods.
- It is likely to occur on long straight roads where there is Armco railings and/or similar barriers.
- Does not affect accuracy of speed readings.
- May cause the displays to blank.
26
26. In moving mode what 3 functions must the radar perform?
1. Determine and display patrol speed.
2. Determine combined speed of radar and target.
3. Determine and display target speed.
27
27. In moving mode what must the radar instrument obtain?
It must obtain 2 doppler shift frequencies. Patrol speed (low doppler) and combined speed (high doppler).
28
28. How is patrol speed obtained? *
From the energy reflected off the roadway or surrounding stationary objects. Ideally 7 metres to the front of the patrol vehicle
29
29. How is Gross Error defined?
An error greater than 3 Km/h.
30
30. When conducting a correlation check of the digital speedometer and the patrol speed of the radar what speed range must be verified?
It must be verified that the accuracy of the digital speedometer is within plus or minus 2 Km/h of the patrol speed displayed on the radar instrument.
31
31. What is harmonic detection and what causes this?
Harmonic detection occurs when reflections from a targets is the same as the patrol speed reflection (Both vehicle have the same speed of travel)
32
32. What 4 behaviours associated with radar energy may be experienced by Silver Eagle III operators?
1. Reflection: The radar relies on energy being reflected from the target to operate.
2. Refraction: When a ray of light meets the surface of separation between two transparent media, it is sharply bent or refracted when entering the denser medium.
3. Diffraction: When electromagnetic waves are restricted by an aperture or by the edge of an obstacle, some of the energy spreads into the region not directly in line with the source.
4. Absorption: Frequency will be absorbed by some compounds, most common of which is water.
33
33. What is the Radar tolerance- *
Stationery mode + or – 1km/h
Moving mode -2 + 1km/h
34
34. Why should a constant patrol speed be maintained? *
1. To allow easier and faster acquisition of the patrol speed.
2. Allows more time being devoted to calculating Closing Rate Speed.
35
35. Tuning fork test?
Big- 45km/h
Little-80 km/h
Difference 35kmh
36
Three main points for conducting tuning fork testing? *
1. To establish that the transmitter/ receiver is functioning.
2. To establish the accuracy of the logic control unit.
3. Tolerance is plus or minus 1km/h
37
37. What is the Silver Eagle III Testing Procedure?
1. Visually check correct antenna placement and alignment.
2. Press power switch on. Visually observe all segments illuminate followed by internal test. Certify days remaining.
3. Check and adjust audio settings by press the menu button on the display unit or on the remote
4. Check and adjust range. Then press ‘check’ button to exit display menu.
5. Carry out a tuning fork test using either the mechanical electronic turning forks
38
38. What are the requirements for a valid speed check? (Know verbatim)
V- 1. Visual observation and estimation of the target’s speed.
O- 2. Observe the numerals in the patrol and target displayed.
C- 3. Clear and continuous tone (however pitch may vary).
C- 4. Correlation between patrol speed and checked speedometer
D- 5. Duration of check (step two, three and four) must not be less than three seconds.
M- 6. Minimum of 200 meters between targets of similar size.
39
39. Name 5 Operational Guidelines of the Silver Eagle III radar?
1. Radar / Lidar is to be set up and tested as per instructions.
2. At all times the instrument is to be in ‘hold’ mode until a target is visually observed.
3. Whilst patrolling, police vehicles must maintain a reasonable, constant patrol speed.
4. The minimum detection time is 3 seconds for a valid radar speed check.
5. Ensure a clear audio tone is heard throughout the period of the check.
6. Radar / Lidar must not be used in inclement weather.
7. Avoid subjecting the radar display unit to direct sunlight for extended periods.
40
40. A Sections 137 certificate must be issued within what time period? *
12 months from the date of the offence.
41
41. During a check you find a seal broken or wiring harness damaged on the Radar/Lidar. What do you do? *
Remove the Radar/Lidar from service and send the instrument to the Radar Engineering Unit (REU) for repair with a report.
42
42. What are the 4 exemptions to having speed measuring evasion articles?
1. The person was going to surrender the article.
2. The person did not know, or could not have reasonably known the article was fitted or being carried.
3. The device was not built as an article.
4. The vehicle was subject to a notice, requiring removal of the article within a specified time, and the notice had not expired.
43
43. When must the radar be tested and by whom?
1. At the start of the shift (By the operator).
2. At hourly intervals (By the operator).
3. At the end of the shift (By the operator).
4. Every 12 months (By the REU).
44
44. What must a vehicle be equipped with for radar operation?
1. Checked speedometer.
2. Shielded cable.
45
45. In moving mode can the speed of a vehicle be checked when travelling in the same direction?
Yes, however the target vehicle would have to be traveling at twice that of the patrol vehicle plus the threshold. Even then the display would be the threshold speed. (This feature has been disabled in the Eagle 3 but is still in manual)
46
46. What is relative velocity?
The component of speed that travels directly towards the radar.
47
47. HOW TO SET UP THE ANTENA
1m-2m above ground level.
Face front and parallel with the roadway in moving mode.
Face front or rear and parallel with the roadway in stationary mode.
Protection cover must not be removed by operator.
Any repairs to the antenna are to be completed by Radar Engineering Unit.
Antenna must be not used in inclement weather.
48
48. Why should radar be used when traffic is light-
Easier target identification.
As to comply with the only one vehicle of a similar size within 200m.
49
49. Responsibilities of utilising the radar? *
1- Within 50 metres of a speed change (60km/h zone becoming a 50km/h zone) unless;
A. Speed is excessive (20 km/h of the speed limit).
B. Subject of complaint.
C. Where there is a high accident history.
* this does not apply to school zones.
2. At any location bring legitimate criticism or give rise to the complaint that they are a means of raising Government revenue.
3. When operating speed measuring instruments police should be aware of Australian Design Rules pertaining to motor vehicle speedometers.
50
50. How to overcome interference
Change locations
51
51. What is Interference
Any external event which adversely influences the normal operation of the radar.
52
52. Combined Speed (Closing rate speed)-
Combined patrol and target speed.
53
53. Target Speed
Obtained by subtracting patrol speed from closing rate speed.
54
What are the 5 main effects which a radar operator could encounter?
1. Cosine Effect. *
2. Split Speed. *
3. Differential Effect. *
4. Double Bounce. *
5. Add – On Speed. *
55
What is Cosine Effect?
Cosine Effect is the angle between the direction in which the beam is transmitted and the direction of travel of the target. Ideally the target should travel directly towards the radar in the centre of the effective beam, However, this would create a dangerous situation. To overcome the danger, the radar is operated offset to the target creating an angle.
56
To avoid errors due to Cosine Effect what should the operator do?
Apply the 7:1 ratio. The 7:1 ratio determines the range at which any speed check must cease or commence.
Correlate patrol speed with the checked speedometer.
57
What causes a Split Speed to occur?
Usually occurs when the patrol vehicle is travelling more than 120 Km/h. The radar is unable to obtain patrol speed from the roadway in front of the vehicle and obtains its speed from some other angle to the side. Due to cosine angle, the displayed patrol speed is slower than true ground speed. Radar obtains true ground speed but already has patrol speed so it treats it as closing rate speed.
The difference between the displayed patrol speed and closing rate speed is displayed as target speed.
58
What is Differential Effect?
Differential Effect occurs when operating the radar in moving mode behind a large moving
vehicle/object.
The vehicle in front is treated as a stationary object.
A stronger reflection is obtained from the vehicle in front.
The difference in speed of the 2 vehicles (patrol vehicle and the vehicle in front) will be displayed as the
patrol speed.
Radar obtains closing rate speed of patrol vehicle and target vehicle.
It calculates the target speed by closing rate speed minus displayed patrol speed and displays the target
speed in the target window.
Displayed target speed is in error by the difference of the 2 patrol speeds.
59
What is an example of Differential Effect? And avoid errors due to Differential Effect what should the operator do?
A police vehicle travels behind a truck and as it approaches the truck the radar treats the truck as if it was stationary and the radar will display an incorrect patrol speed due to a stronger reflection being received from the truck. --
Do not check the speed of a target whilst the police vehicle is close to the rear of a large moving object.
Verify the displayed patrol speed by correlation with the checked speedometer.
60
What is Double Bounce?
Energy reflected from a stationary object ie; bridge or large billboard sign, back towards the patrol vehicle which is reflected by the patrol vehicle back towards the stationary object which is reflected back again.
Police vehicle becomes host vehicle and target vehicle.
Target speed will be the same as true patrol speed plus or minus 1km/h.
Keep radar in hold until a legitimate target is visually observed.
61
What is an example of Double Bounce?
A police vehicle releases the beam of the radar in the absence of a legitimate target and is reflected by a billboard back towards the police vehicle which is reflected back towards the billboard which is reflected back again. This allows the police vehicle to become the target vehicle as well as the host vehicle.
62
What causes Add – On Speed to occur?
Occurs when the patrol vehicle is travelling below the patrol speed threshold.
Occurs when establishing patrol speed, any oncoming vehicle within 50 metres is treated as a stationary object.
Closing rate speed is displayed as patrol speed.
PHASE 5
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