> Thanks for those ideas Mike. That NVE website looks pretty interesting too.The
> app will be - **if** it goes ahead? - to photograph cars on a country road.
> It's a big station abutting a nat park and they want to monitor who uses roads
> at back of their property by photographing vehicle rego plates. It's semi arid
> Outback country so I think dust will be the killer - how do you photo thru a
> dust cloud thrown up as the vehicle moves away? If go for a forward shot, you'd
> have probs with the vehicle's headlights at night. Plus flash/illumination
> probs. Still thinkin' about that.

Do your local license plates have raised letters, or are they painted?
Oblique lighting could do a good job of exposing the plate numbers,
and from an angle, you may be able to avoid the headlight glare.

> Don't want to use inductive loops or anything that needs cables spread out - it
> needs to be smallish & easy to deploy so solid state sensors look attractive.
> The range of the sensor would be an issue - it needs to detect a vehicle from
> the side of the road. That's not far as we're talking dirt tracks & large 4x4
> vehicles mostly. don't need auto rego-number reading. Hmmm ... a laser bounced
> off a corner reflector is a possibility, maybe. Would you say solid state MR
> sensors could detect a vehicle in a situation like that?
> Debbie

Yes.  Those solid state GMR sensors would be able to detect them from a
reasonable distance- probably several meters.  I think I recall seeing
an appnote
about it on the NVE website.

Mike H.

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