SmarTek Systems SVS-1 User Guide-Part B - Manual (Page 44)

SVS-1 – Setting Detection Zone Sensitivity Parameters (continued)
Circle Zone Radius– Specifies the size of the Circle Detection Zone. The circle zone is located at the up road end of
the corresponding Line Detection Zone and is used as part of the directional detection criterion. The Circle Zone
size is dependent on the specific image of the intersection stop line area. The Circle Zone radius should be chosen
so that it’s diameter is approximately 1/5 the width of the lane it resides in. The default value is 12.
Circle Zone Quantization Threshold – Specifies the pixel value quantization threshold to be used to determine
which pixels contained in the circle zone are used for processing to obtain the Circle Zone detection
measurement. The default value is 15.
Circle Zone Detection Threshold – Specifies Circle Zone detection sensitivity and may be adjusted by changing the
Circle Zone Threshold value . Increasing the Circle Zone Threshold will decrease sensitivity. Circle Zone Detection
Threshold default value is 12%.
Measurement Alpha – Specifies the smoothing factor to apply to all detection measurements (Circle Zone and Line
Zone measurements). The default value for the Measurement Alpha is 0.200.
After setting the parameters for a specific Line Zone (and corresponding Circle Zone), the
parameters for all other zones may be set to the same values using the Set Parameters for
All Zones button. This does not change positions of the zones, just the sensitivity
parameters.