Imagine I had a laser pointing straight down from a car, and a detector to see when the beam was reflected back up. Now suppose the detector samples at something like 1 MHz. If I were driving down the highway at speed, and I put a small mirror on the road surface under the path of my car and laser, I would have many 'True' readings as I pass over the mirror.
What would be the simplest approach to having something similar using RF of some type? Instead of an optical mirror, I would use a thin strip of metal as a reflector. It would be just 1 cm wide in the direction of car travel (but could be a meter in length perpendicular to said direction). It could be on the surface of the pavement, or ideally even 1 or 2 cm beneath.
If this works the way I would like, if one knew the speed of the car, one could measure the width of the metallic strip by looking at the time stamps from when the RF signal was reflected and when it wasn't. The overall distance between the bottom of my sensor and the reflective surface would something like 0.5m - 1m.
• I could imagine using some kind of mask to block the RF except for that in the shape of narrow beam
• Microwaves of mm waves might be better than longer waves?
• SnR consideration: I am just attempting to detect the presence of a reflector, and not trying to pass data
• The beam needs to be narrow in the direction of travel, but it could be wide in the perpendicular direction
Any ideas for how feasible this would be to make or what kind of technologies would be applicable?
Thanks!
What would be the simplest approach to having something similar using RF of some type? Instead of an optical mirror, I would use a thin strip of metal as a reflector. It would be just 1 cm wide in the direction of car travel (but could be a meter in length perpendicular to said direction). It could be on the surface of the pavement, or ideally even 1 or 2 cm beneath.
If this works the way I would like, if one knew the speed of the car, one could measure the width of the metallic strip by looking at the time stamps from when the RF signal was reflected and when it wasn't. The overall distance between the bottom of my sensor and the reflective surface would something like 0.5m - 1m.
• I could imagine using some kind of mask to block the RF except for that in the shape of narrow beam
• Microwaves of mm waves might be better than longer waves?
• SnR consideration: I am just attempting to detect the presence of a reflector, and not trying to pass data
• The beam needs to be narrow in the direction of travel, but it could be wide in the perpendicular direction
Any ideas for how feasible this would be to make or what kind of technologies would be applicable?
Thanks!