Do radar guns work at night?
93467
Yes, DEFINATELY! Watch out and Be Careful!
331821
no\nthey are worse at night because you can't see them coming
1150394
No but they do have landing lights.... radar and advanced avionics pretty much take care of everything else.
404591
I only have a toupee radar.  I can always spot a toupee on a man.
561483
Probably Radar - measuring the doppler shift (difference between transmitted frequency and reflexted frequency).\n\nDepending where you are, many police forces use laser systems these days. They are more precise and faster, but require someone to aim it at the target - not really suitable for a tennis ball!
238433
a 12 bore shot gun and a night light
51986
Are you referring to millimeter wave radar? I'm not familiar with any system that includes lasers.\n\nMillimeter wave radar is just radar of a particular band (somewhere between 30 GHz and 300 GHz). Some applications include cloud radar to detect the tops and bottoms of clouds; using doppler techniques to detect vertical movement within a cloud; and adaptive cruise control in cars to maintain a pre-set distance.
982460
Sure...you can always ask. many times, the police will just show you. They did the last time I was caught. The radar guns are calibrated regularly and are accurate within 5 km/h
486100
Missiles use passive IR/UV sensors. The missiles look for the infrared light (heat) produced by the target airplane's engines and track the airplane by following that light. The missiles also identify the UV "shadow" of the target and use that identification to distinguish the target from other heat-producing objects.\n\nIf you have read about motion detectors, you know that motion-sensing lights use passive infrared sensors. The sensors in a motion-sensing light are tuned to the temperature of a human being. They look out at the world, and when they see a sudden change in the amount of infrared light they are sensing, they assume it's because a person walked into the area, and they turn on the light.\n\nA motion-sensing light needs only one sensor. A Stinger missile needs a whole array of them, because its job is to track the target while it is flying. The nose of a Stinger missile has, essentially, an infrared digital camera in it. This camera might have an array of anything from 2x2 (in older designs) to 128x128 (in the newest Sidewinder design) infrared sensors that receive an infrared image of the scene. When the soldier gets ready to launch the missile, the missile must have the target visible in roughly the center of this sensor.\n\nWhile the missile is flying, the image of the airplane that it is trying to hit may become off-center on the image sensor. When it does, that tells the missile that it is off-course, and the guidance system in the missile has to decide how to get back on course. This is where proportional navigation comes in. The missile looks at the angle of off-centeredness and changes its angle of flight proportionally. In other words, it uses a multiplier. If the multiplier is 2, then if the guidance system thinks it is 10 degrees off course, it will change its flight direction by 20 degrees. Then, a tenth of a second later it will look at the angle again, and change again. By over-correcting this way, it lets the missile anticipate the path of the moving plane in the same way that you anticipate the path of a moving object. If you are a quarterback trying to throw a ball to a receiver running across the field, you would not throw the ball toward where the receiver is -- you would throw it toward where he will be when the ball arrives.\n\nObviously, the guidance system is more involved than this. The image sensor is riding on a rotating, gyrating missile at Mach 2, and it is trying to hit a small target that may be flying at Mach 1. It is not a simple problem. But this is the general idea.
900191
Try working a job at night.
482962
Radar works because radio waves are reflected off of many objects. Stealth fighters are designed to hide from radar by minimizing the amount of radio waves reflected. I am sure a technologically advanced civilization could hide from our radar, however that would also imply that they want to. If they were trying to make contact, I am sure they could make sure we see them on radar.
122602
The first poster is correct.  The link in "sources" gives a chart showing the RF spectrum allocation for the U.S.  Police Radar is at 9.5-10 GHz.  Satellite TV is at 12 GHz.\n\nThe second link provides information on the politics and economics of frequency allocation.
291902
With "Google Earth" you can see a radar image, but it will be fuzzy.  Try it, though.  It is fun for a few minutes, but you have to download it.
640044
Sometimes by radar, sometimes by infared (heat)...at least these are the two most common.\n\nThe missle usually locks on to the greatest contact signature, heat or radar, but can be overridden by the pilot or the weapons officer in a multi-contact situation.
1024100
No, he does not have to show you. If you decide to plead not guilty, the officer can be questioned, in court, about the radar gun he used, it's operation and maintenance.
1161304
Partially yes.\nIf it is within the heat seeking range and the radius of target is big enough to make the missile follow its route, it can happen. The missile however can not make a sudden and sharp U-turn on very short & split second notices.\nThat is where the reflexes, the professional skill and sharpness of the pilot counts.
1005598
I believe it's a.\n\nHere is what i found:  \nDoppler radar uses the Doppler effect to measure the relative velocity information from a radar system. The Doppler effect shifts the frequency of the radar reflection based on the relative velocity (speed) of the "target", allowing for the direct and highly accurate measurement of speed.