3. Optimising the radar mount angle
Levelling and optimising the radar position
The ClearWay Radar has a spread vertical beam, however maximum power is within a 2 degree main lobe. For optimum detection performance it is important that each sensor is level in relation to the area that it surveys. Level may not mean absolutely horizontal. For example, if the site has a slope it is necessary to incline the sensor in line with the slope to obtain optimum performance.
The exaggerated examples below show how a sensor with an incorrect incline could miss targets which are lower down the slope:
On this page:
The recommended procedure to optimise the radar is to use two radar targets on tripods either side of the radar.
Use the RadarView Lite utility to view the resulting radar images and adjust the tilt of the mounting plate until the signals from each target are equal. Please see Using SPx RadarView Lite for details about setting up and using RadarView Lite.
To level and optimise the radar
In line with the limitations of the site and taking all appropriate safety precautions, position the two targets equal distances (at least 150 metres, if possible) either side of the radar along the carriageway. The targets must be at the same height (1.5 metres is suggested), while the area behind each target should be clear for 10 to 15 metres. The aim is to maximise the signal level on both the targets.
Use the RadarVIew Lite utility to view the resulting data and use the A-scan function to view the signal level of the target.
Using a digital inclinometer, ensure that the radar is level across the carriageway. Then adjust the tilt of the radar (on the threaded studs of the mounting plate), to maximise the signal level on the 2 targets, using the gradient of the road around the radar as a starting point.
If this method cannot be used (for example live carriageway), then as a minimum the road gradient should be measured using a digital inclinometer in several locations to gain an average, and the radar matched to this. However, if possible and especially if the road is obviously not flat, use RadarView Lite to view the radar data and adjust the tilt to have an equal amount of data either side of the radar.
The sample screenshots from RadarView Lite shown here show (first) an uneven amount of data and (second) a more even distribution of data either side of the radar.
An uneven amount of data from the two targets...
...a more even distribution of data either side of the radar
Next: 4. Using the Vertex interface