I refer to the recent correspondence on the installed speed cameras.
Dr Ian Micallef tries to impress the readers that “the choice of the particular make of the speed cameras was reached after long deliberation” and “the system uses a tracking radar which measures the speed of vehicles up to 21 times per second”. He continues to point out that the radar “automatically checks that the radar is correctly calibrated every so many minutes”.
Without going into detail on the operation of radar and furthermore the concept of Doppler Effect, the self-check of any system will only check that the system is functioning properly.
In simple terms, if I switch on a heater it is actually heating; if I switch on a light there is actually light; if I start a washing machine, water is actually flowing into the system. It does not and it cannot know whether its timing circuit is actually running at its pre-designed frequency. Should this timing vary, the measurements will be way out of reality. There is no way that the same apparatus can verify that this oscillator (or timer) is actually calibrated.
Let me clarify: any measuring instrument has to be calibrated. This is no easy task. Any test equipment used in the calibration of secondary equipment (in this case the police radar / camera) has to be certified itself. The calibration certificate will indicate what test equipment has been used, the date and validity of its own calibration, the conditions when these tests were carried out, and other details. Even if a “calibrating oscillator” is incorporated into the system, this itself has to be calibrated and certified!
What happens if this is “out of calibration”? Back to my examples above, if I switch on a light and the batteries (or mains) are low the light will still come on, but dimmer than it should be; if I switch on a heater and it has a defect, it might still heat but the set temperature will take longer time to rise than that specified; if the water flow to the washing machine is reduced, the machine will still function but it will take ages to actually start washing. The same happens to the speed cameras. Should the “master timer” be out of calibration, the measurements taken will be false. It stands to reason, then, that if there is no calibration certificate approved by a recognised body these measurements cannot be accepted.
As confirmation of the above I quote an excerpt from website www.answers.com/topic/road-rule-enforcement-camera:
“Verification and system testing”
“In the UK, every speed camera must be calibrated and certified before the images from it are acceptable to the court, including the cameras used in police vehicles. Several speeding prosecutions have failed in the UK due to out of date calibration certificates.
“The pictures taken by road-rule enforcement cameras must usually be viewed by a person before any infringement notice or ticket is issued to the driver, and judged to be satisfactory or not. This step is known as verification, and is a standard legal requirement in nearly all jurisdictions. Verifiers typically must check some or all of the following:
• “That there is no sign of interference with the vehicle detector by objects other than the alleged speeding vehicle,
• “that the licence plate is unambiguously readable according to a legal standard,
• “that the make and model of vehicle matches that recorded by the licensing authority for the number plate.”
Furthermore to the radar being calibrated, there are other shortcomings in the use of radar as a speed measurement system. Radar cannot determine which target reflected off the waves. If there are two cars both travelling in close proximity, no one can tell who is responsible for the radar reading if such is obtained.
Apart from the above facts related to the equipment’s accuracy, let us remember that our roads are far from even and level. The primary principle of Doppler Effect is on horizontal movement. Doppler measurement has no effect on vertical movement. In other words vertical movement cannot be measured using the Doppler radar. Our roads, viewed from any fixed point, are very rarely level; probably better described as sinusoidal. Hence, notwithstanding if the units are calibrated at the factory, on installation at any point they have to be verified for correct reporting of the vehicle’s speed in either way of traffic and on the length of the “measuring path”.
Whether the units comply with regulations is a different matter. This will usually take into consideration that the operation of the units is “safe”. Whether they read-out correctly or not is irrelevant. A unit can be installed incorrectly and yet be still compliant.
Speaking of “safe” operations, let us not forget how many warnings we have read about mobile phones and that prolonged usage should be avoided as much as possible. How many times have we heard and learnt about microwave radiation, as in microwave cookers? The same applies to these radars. While the emissions from a mobile phone are usually measured in microwatts, no mention of the output power of these radars has been publicised. Let us take, for example, the camera fitted on Xemxija hill. Pedestrians walk in very close proximity to the camera. Its height level is not much more than that of a normal person. Having to be pointed downwards to be aimed at traffic, it releases considerable microwaves on pedestrians who happen to be passing by. It is usually required that a “keep away” area is marked close to the transmitting device, although it is not practical to keep pedestrians away from a narrow pavement. Whatever the local authorities say about the radiation level being “safe”, why should we believe them unless this is certified by independent bodies?
The authorities are striving hard to regulate the common people on the use of motor vehicles, namely with the introduction of the VRT and now by the “practice” of other drivers to report exhaust emissions by SMS. It is therefore expected that the authorities regularise themselves, primarily where safety is a main concern. It is also expected that proper road signs be put up on all roads, that they are not obstructed by trees and are visible from a good distance while driving. While the newly built roads are a definite step towards better driving, they are just a fraction of all the roads that need proper surfacing. Let’s not forget the excessive taxes we have to fork out.
A. Grima
BIRGUMA