what is this thing?

[griz]

I pass this on the way to work.  Because of its location I am assuming it is some kind of security device but have never seen anything like it.  Anybody know?

[Tallpine]

Alien spacecraft that just landed...?

[AJ Dual]

Looks like the LIDAR/Laser speed detectors some of the more well-heeled PD departments have on top of their squad car's light bar. Except here it's on a stand and a battery pack or something.

Either that, or an automatic license plate recognition system. Looks for suspended plates, plates tied to warrants etc.

[vaskidmark]

There's what appears to be a sign underneath it.  Lift it up and see if it tells you what the thing is?  If that proves unhelpful you might, while standing there, look to see if it has any nomenclature or warning stuff on the case.  Just trying to be helpfull, Boss.

My guess would be some sort of surveying instrument, unless the lens(es) are pointed at either the road or some obvious target.  If that is the case I amend my guess to some sort of survelience device.

Most curiously there does not appear to be anything securing it in position other than nominal Earf gravitational forces.  If closer examination proves that to be the case then perhaps you and some associates could remove it to a more convenient location for perusal overnight and then return it in the morning festooned appropriately?  (Srsly, don't do that.  It's agin the law and you might strain yourself lifting it onto a pickup truck bed.)

stay safe.

[GigaBuist]

I bet if you put some duct tape over the lens you'll find out what it is... when a cop shows up at your door. :)

[HankB]

. . .  Because of its location . . .

And the location is . . . ?

Anyway, that thing on top sort of looks like a target for a paintball gun . . . 

[griz]

It's in the median after the entrance gate to a military base, so it "looks" directly down the road.  Maybe it is a speed thing since the posted speed is 25 and people tend to stretch that.

[brimic]

Maybe it is a speed thing since the posted speed is 25 and people tend to stretch that.

I love those radar guns on trailers that SHeriff's department place on streets to get people to slow down. Their biggest unintended consequence is encouraging kids to play in the street- either trying determine how fast they can get on their bike or determining the speed of their fast ball. We had one in front of our house for about a month- until the 12 year old kid next door  broke it with a slapshot.

[230RN]

That doesn't look radarey.  Looks camera-ey.  May have a laser to sense distance for triggering.

Tell you the truth, I'm getting a little paranoid/wary about being bombarded everywhere from radar.  I started to get picked up by one of those roadside radar displays from about 1/4 mile away and had to wonder about that.

Then there's those microwave door openers in stores and stuff. 

"They" say it's "safe," but what's the upper limit for "safe?"  I know that microwaves will cause polymerization of things like egg whites and the vitreous humor of the eyeball, and any polymerization thereof is irreversible and cumulative.

And what's the lower limit for a frequncy being "safe?" Is there a sharp cutoff point for "safe" versus "unsafe?"

And did I read about birds flying through high-powered radar beams getting zapped?

Poo-poo my concerns if you will.

 

Terry, 230RN

[brimic]

"They" say it's "safe," but what's the upper limit for "safe?"  I know that microwaves will cause polymerization of things like egg whites and the vitreoua humor of the eyeball, and any polymerization thereof is irreversible and cumulative.

I don't know the exact science of all of it offhand, but the energy of the radar waves is going to decrease dramatically through distance.
Not sure if microwave ovens use a different frequency than radar, but I know that Microwave ovens are specially tuned to cause vibration in water molecules, which is probably a different wavelength than normally used in radar.

[Tallpine]

Poo-poo my concerns if you will.

These are not the paranoids you're looking for.

[GigaBuist]

Not sure if microwave ovens use a different frequency than radar, but I know that Microwave ovens are specially tuned to cause vibration in water molecules, which is probably a different wavelength than normally used in radar.

Microwave ovens operate right around 2.45Ghz.  RADAR is all over the map.  There's a table here:  http://en.wikipedia.org/wiki/Radar#Frequency_bands

From that chart I gather speed RADAR guns used by police are running 18-24Ghz.

[birdman]

Looks like the LIDAR/Laser speed detectors some of the more well-heeled PD departments have on top of their squad car's light bar. Except here it's on a stand and a battery pack or something.

Either that, or an automatic license plate recognition system. Looks for suspended plates, plates tied to warrants etc.

Pretty sure it's the latter.  While the algorithms to extract plate info from video are available, the rapid aim/slew for Ladar (and I don't see a microwave emitter) to autonomously do a speed check aren't available (as far as I know) in that type of device.  When mounted on a police cruiser, those little turrets are just for the plate scanners, the radar emitters are usually elsewhere.   So I'm going with plate scanner.  If it was for speed checking/ticketing, it would be a photo-radar install (which looks totally different).  I'm guessing they use it to monitor security (correlate with approved vehicle/visitor lists).

[seeker_two]

Looks like a public pillowcase holder to me..... 

[birdman]

Microwave ovens operate right around 2.45Ghz.  RADAR is all over the map.  There's a table here:  http://en.wikipedia.org/wiki/Radar#Frequency_bands

From that chart I gather speed RADAR guns used by police are running 18-24Ghz.

Depends on the gun, police use X, K, and Ka band radars (and I think they may have also used Ku as well.

[RoadKingLarry]

I don't know the exact science of all of it offhand, but the energy of the radar waves is going to decrease dramatically through distance.
Not sure if microwave ovens use a different frequency than radar, but I know that Microwave ovens are specially tuned to cause vibration in water molecules, which is probably a different wavelength than normally used in radar.

Inverse square of the distance sort of thing.

What kind of power hits someone has a lot to do with the transmitted power. Not much to worry about from speed control RADAR at the distances we are going to be at and the metal of the car is an effective shield to the RF anyway as is the glass to a lesser amount.

[Gowen]

Could it be a surveying device?

[Boomhauer]

anyway as is the glass to a lesser amount

I believe the passivated glass used in modern cars is going to provide a bit more protection from RF than normal glass.

Which is one of the reasons glass mount antennas tend not to work so hot these days...

[230RN]

I believe the passivated glass used in modern cars is going to provide a bit more protection from RF than normal glass.

Which is one of the reasons glass mount antennas tend not to work so hot these days...

^ Good info. But bicyclists, pedestrians?

And the inverse square law only holds in its "standard" sense for uniformly divergent radiation.  As the divergence of a beam narrows, however, the reduction in energy per unit distance is less and less until the beam does not diverge at all --as in a tightly-focused laser beam.  The only attenuation is from other stuff like dust in the air.

Sure, take a naked light bulb and its illumination varies with the square of the distance nicely.  But put a focusing reflector (or lens) on it and the illuminated area is no longer spherical, but in a narrow beam.  The inverse square law still holds, but the distances are greater.  Taking it to the extreme, a perfectly parallel beam will have the same illumination however far away it is measured, except for absorption by and reflection off of "stuff" between the bulb and the point of measurement.

[birdman]

^ Good info. But bicyclists, pedestrians?

And the inverse square law only holds in its "standard" sense for uniformly divergent radiation.  As the divergence of a beam narrows, however, the reduction in energy per unit distance is less and less until the beam does not diverge at all --as in a tightly-focused laser beam.  The only attenuation is from other stuff like dust in the air.

Sure, take a naked light bulb and its illumination varies with the square of the distance nicely.  But put a focusing reflector (or lens) on it and the illuminated area is no longer spherical, but in a narrow beam.  The inverse square law still holds, but the distances are greater.  Taking it to the extreme, a perfectly parallel beam will have the same illumination however far away it is measured, except for absorption by and reflection off of "stuff" between the bulb and the point of measurement.

No such thing as perfectly parallel, thanks to that bastard Huygens.  The inverse square law (flux is inversely proportional to distance squared) holds for ALL EM, when in free space propagation, past the Gaussian beam waist (or focus if it's a non parallel wavefront at first).  The best you can do for divergence is lambda/D (for the 1/e point of a perfect Gaussian beam)-- meaning, for X-band radar, (3cm lambda) and a 6cm emitter, the beam is almost 30deg wide!  And if you measure the intensity, it follows an inverse square law.  Now take a huge x-band radar...(AN/TPY-2, SBX). Narrower beam, but still follows inverse square. 

[charby]

Could it be a surveying device?

That is what I thought also, or a laser vehicle counter.

[Chuck Dye]

For the paranoid, that gadget is clearly a long range rifle target, nu?

Or, for the truly paranoid and well equipped, ground zero! 

[Jamisjockey]

Could be any number of things. Google searches for all the ideas posted here didn't turn up anything looking exactly like that. 

One thing that does come up and looks similar, though, is a flir unit.

For a private boat:



Here's a military one:

[230RN]

No such thing as perfectly parallel, thanks to that bastard Huygens.

I know.  My "perfectly parallel beam" was for illustrative purposes, which is why I used the phrase "Taking it to the extreme..."  And for ordinary distances and ordinary focusing techniques the dot from my <5 mW laser pointer can be seen for hundreds of yards on a dark night.

Parallel enough, wot?  Even though it gets to be more of a "patch" out there than a dot.

If it were not focused, its illumination "out there" would be virtually nil.

-------
Caveat.  If anyone's going to play around with the laser sights on their guns in this matter, please make sure the damned thing is empty.

[birdman]

I know.  My "perfectly parallel beam" was for illustrative purposes, which is why I used the phrase "Taking it to the extreme..."  And for ordinary distances and ordinary focusing techniques the dot from my <5 mW laser pointer can be seen for hundreds of yards on a dark night.

Parallel enough, wot?  Even though it gets to be more of a "patch" out there than a dot.

If it were not focused, its illumination "out there" would be virtually nil.

-------
Caveat.  If anyone's going to play around with the laser sights on their guns in this matter, please make sure the damned thing is empty.

A laser pointer is actually collimated (focus at infinity), with the beam waist at the output aperture, if it were focused, it would spread more than a collimated beam.

Anyway, it's splitting hairs