2007-03-27 21:09:56 · 6 answers · asked by jean 1 in Cars & Transportation ➔ Aircraft
Magic and GPS have nothing to do with radar. Radar systems use certain bands of frequencies that are sent from the radar unit toward the target area, regardless if it is a police type radar or an air traffic/sweeping radar. When the frequencies are emitted, they are sent in calibrated pulses and upon contacting an object/target, those frequencies bounce back to the radar unit. The radar calcluates how quickly those signals are sent and received to determine distance and while the unit is pulsing, it determines speed by calculating the distance as it constantly changes. What this means is if an officer has a radar on you and you are approaching, the signals will return to the radar as it calculates your distance over a specified time. Internally, it calculates your speed based off of distance gain proportionate to time elapsed.
2007-03-27 21:57:10 · answer #1 · answered by Steve D 2 · 0⤊ 0⤋
Would you be referring to the police hand held speed guns or surveillence radars?
In most cases, the speed is measured using the Doppler shift arising due to the relative motion between the radar and the target (Continuous Wave systems). Another method is indirect calculation based on the difference in return times of successive echoes of Pulsed radar systems.
Can elaborate if you narrow down the scope of the question.
2007-03-28 04:25:17 · answer #2 · answered by ? 6 · 0⤊ 0⤋
A Radar Gun is used to send out radio waves of specific frequencies in a chosen direction. The traveling waves then bounce off objects, including vehicles, and return to the radar gun 's receiving station. When the waves reflect off a moving vehicle, a measurable frequency shift, called Doppler Shift, occurs. The radar gun computer then uses the frequency shift to calculate the speed of the moving vehicle.
2007-03-28 04:21:38 · answer #3 · answered by mitsugirl 4 · 3⤊ 0⤋
If you are refering to speed of the aircraft then it's not the radar which tells the speed of the aircraft, it's PITOT Tube. During cruise the air rushing into it deflects a bourden tube which moves the speed needle. Generally the pitot tube is kept at a at high temperature (calibrated) so that there in no ice formation on the tip when the aircraft flies at high altitudes where the temperature falls down to - 40~ - 45 deg. C.
2007-03-28 05:16:39 · answer #4 · answered by Ask Dr. Dingo 3 · 0⤊ 1⤋
By capturing two spots, GPS positions and then get time of distance covered.
2007-03-28 04:15:54 · answer #5 · answered by Talha 4 · 0⤊ 2⤋
magic
2007-03-28 04:12:34 · answer #6 · answered by cowboyup 2 · 0⤊ 2⤋