measure distance to side of passing automobile at 100km/h

[MikeFrank_imported]

Problem:

Measurement of the distance to the side of an automobile,
(perpendicular to the direction of travel)
as it passes at 100km/h.

min. sample rate: 100 Hz
range: 1 to 10 meters
resolution: +/- 3 cm or better
output:analog 4-20mA


I have found the following:

1) ultrasonic sensors won't allow a high enough sample rate (due to speed of sound)

2) lasers will be affected by sunlight (test track has a north south orientation, laser will be pointing towards the sun part of the day)

3) microwave sensors may have too large a beam to accomplish the sample rate


Any ideas?

I still believe microwave is my best bet.

Mike Frank
frankm@mcmaster.ca

 

[IRstuff]

Please do not cross post.

Answered thread247-131744

TTFN