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The difference in range by frequency of a radar, is minimal.
Radar range is more limited by the curvature of the earth. Different frequencies are of more use in discrimination of the returned signal.
3cm wavelength is popular on ships, as a good all round use. It can get blinded by rain and limited by fog. 10cm is also used and can see through heavy rain, the discrimination is poor however and objects close together can merge into one.
What else can I help you with?
How does radar calculate speed of an auto?
Radar calculates the speed of an object by measuring the Doppler shift in the frequency of the transmitted and received radar signals. As the radar waves bounce off the moving object, the frequency of the returning signal is different from the transmitted frequency. By analyzing this frequency shift, the radar system can determine the speed of the object.
Why is reflection of signal useful?
Reflection of a transmitted signal is the basic premise of radar and sonar.
How does the frequency of a car's returning radar signal chang if the car moves away from the you radar source?
If a car moves away from a radar source, the frequency of the returning radar signal decreases. This is due to the Doppler effect, where as the car moves away, the wavelength of the signal is stretched out, causing a decrease in frequency.
What are the parts of a Doppler Radar?
Same as the "regular" radar, except that the receiver is a bit different. In regular radar, the receiver looks for the returning signal on the frequency the transmitted pulse was sent out. Yes, it sees" Doppler shifted signals, but with decreasing sensitivity. And it does little with them but combine them with the signal on the frequency of the transmitted pulse. With Doppler radar, the receiver looks for a "band" or group of frequencies around the frequency at which the transmitted pulse was sent out. These "nearby" frequencies represent returns from materials or substances that are moving relative to the transmitter (toward or away from it). And the receiver works with a microprocessor based "analyzer" to paint a picture based on those returning signals that are near the frequency of the transmitted signal and not right on it. Basically, radar has a transmitter, the waveguide to the antenna, the antenna itself, and the receiver. The receiver is plumbed into the same waveguide the transmitter is connected to, but there is a junction (like a "T") where the transmitter and receiver are connected that is capable of directing the transmitted signal out along the waveguide and keeping it from going into the receiver, and then allowing the returned signal to get to the receiver without being "lost" by going back into the transmitter. There is a control system and a display system associated with the equipment as well. Just as one might expect.
What is the nature of a radar signal?
A radar signal is an electromagnetic wave that is emitted by a radar transmitter. It travels through the atmosphere, reflects off objects in its path, and is then detected by a radar receiver. The signal's properties, such as frequency and wavelength, determine its range and resolution capabilities.
What type of radar is able to take advantage of vary small changes in the frequency of the returned signal to give a more detailed radar image?
Doppler radar is sensitive to the changes in frequency of the returned signal caused by the movement of the "target" off which that signal is being reflected. Storm cells are moving concentrations of extremely humid air, and they reflect radar signals fairly well. By using a computer to analyze the small changes in the frequency of the returned signal (compared to the frequency of the transmitted signal - which we know), we can, by looking at this Doppler shift, paint a picture of the storm cell activity. A link is provided to the Wikipedia article on Doppler radar. You can get more detailed information there. The above is correct but is worth noting the following too: Doppler RADAR will be able to detect Doppler shift, but the fidelity to which they detectable or are know to is a function of the Pulse Repetition Ration (PRF) and the number of sample collected. So it depend what frequency you are looking and the fidelity you are looking for. Also note that Doppler is a function of the Carrier Frequency not the pulse modulation, and it should be noted that that some carrier frequencies are more susceptible to water and air molecule resonate then others. Finally the choice of wavelength and polarisation are fundamental to match what your are looking to see.
A police radar detects a vehicle's average speed by recording how far a vehicle travels during a short period time Explain this in further detail?
The question is defective. The description given is not at all the method by which a police traffic radar measures the speed of a target vehicle. The radar unit measures the instantaneous speed of the target by measuring the difference between the frequency of the transmitted signal and the frequency of the echo-return from the target. The frequency of the return signal is Doppler-shifted in proportion to the radial component of the target's speed with respect to the radar unit. The period of time required for the measurement is essentially zero.
What does the Doppler radar measure?
A narrow microwave signal is directed at the moving vehicle at a known frequency, due to its motion the reflected signal will arrive back at the radar at a different frequency, an algorithm in the radar processor converts this difference to give the vehicles speed. Presumably the angle between the cop and the speeder will have to be taken into account as well.
What does radar measures?
It measures the time it takes for a radio signal of a particular frequency to travel to a target and back. It also measures the strength of the signal when it returns. Based on the travel time of the signal, the radar can measure the distance of the target. Once the radar receives the 2nd signal, it can calculate the velocity of the target. The strength of the signal can be used to determine the size of the target.
How is frequency difference and time difference measured in FMCW radar?
Frequency modulated continuous-wave (FM-CW) radar is usually used with a couple of different antennas. One is for the transmitted signal, and another one (or more) is (are) used for the reception of any returns. We usually think of radar as a pulse of electromagnetic energy that is transmitted out, and then a receiver looks for any returning (reflected) signal. In FM-CW radar, the transmitter is "always on" and a continuous signal is being sent. Additionally, the frequency of the transmitted signal is varied (or "swept") above and below a center frequency which the local oscillator runs on and maintains. The new units are largely microprocessor controlled pieces of equipment. They take the now-FM-modulated signal and broadcast it continuously (per the name - CW, which is continuous wave), and the returns are picked up by a receiver. The frequency of the return signal is compared to the instantaneous frequency of the transmitter, and the frequency difference can be looked at by a processor which can derive a time difference between the two signals (based on the differential frequency). This derived time difference will be proportional to the distance to the target that returned the signal. Another bit of processing on the signal returned from that target will produce a rate of change of distance, which can be converted to speed. As the power of the processors that we task with these objectives in mind has increased so dramatically, the processor can plot a course and speed with all appropriate vectors we wish to visualize when it puts up its findings on some kind of display - and in color! Particulars become technical very quickly, but the overview is accurate. A link to the Wikipedia article on FMCW is supplied, but at this writing, the article is still a stub that will supply little more than is here already.
How does police radar have to do with wavelength?
Police radar systems use microwave radar technology, which operates within a specific range of wavelengths in the electromagnetic spectrum. The radar gun emits a microwave signal towards a moving vehicle, and measures the frequency shift in the reflected signal to determine the vehicle's speed. By analyzing the Doppler effect of the reflected microwave signal, the radar system can calculate the speed of the vehicle based on the wavelength of the emitted signal.
How does a Doppler radar differentiates a stationary target from a moving target using Doppler effect?
A Doppler radar differentiates a stationary target from a moving target by measuring the change in frequency of the reflected signal. For a stationary target, there is no change in frequency, while for a moving target, there is a shift in frequency due to the Doppler effect. By analyzing this frequency shift, the radar can determine whether the target is moving or stationary.
