everytime i go through an i pass i get a false laser alert from my v1
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everytime i go through an i pass i get a false laser alert from my v1
This is common in certain Ipass/EZpass booths. In some states they use lidar-based sensors for vehicle size or something (I'm not sure 100%). The EZPass booths in NH set off all my detectors, not just the V1.
I have heard that they use an IR laser to count axles. I, too, have gotten a laser false just as I pass beneath the FasTrak gantry on the toll road. It doesn't happen every time, though - no doubt the laser is aimed down at the wheels so there is no direct LOS, but every once i a while the V1 picks up a bit of scatter.
In the NH EZPass booths, it's something on the roof (ceiling) of the booth with a beam pointed downward. I know this because if I go through the booth with my sunroof open, both the front and rear V1 arrows light, but with the sunroof closed, only the front arrow lights. This is with the V1 on the visor.
North Texas Toll Authority uses this type of laser scanning as well. As noted before, its used to map the shape of the vehicle passing thru the sensor curtain - helps classify trucks, trucks with trailers and passenger cars.
On several highways, the laser scans the vehicle and a camera takes a high-resolution photos of the license plate (no RFID sensor required).
OCR software reads the plate and bills the vehicle owner the appropriate toll amount.
I wouldn't call this a "false". The V1 (including mine - every time on Hwy 121 in Lewisville, TX) alerts briefly when passing thru.
The laser is of the proper wavelength and the V1 alerts as designed.
No cop (hopefully :)) but not a false either.
LabRat
This is a valid form of LIDAR and the V1 is doing its job by alerting to it.