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Why FMCW radar has better range resolution than CW radar?
Sibasankar367
FM CW radar sweeps the Radio Frequency over time. Time in Radar equates to range and results in a high spectral density at every range. CW radar has a much lower spectral density and does not code range with frequency in the same way.
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∙ 14y ago
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Is fmcw radar a doppler radar?
An FMCW radar may make use of Doppler, but it doesn't necessarily.
What is fmcw radar?
frequency modulated continues radar for detecting the target it generates the signals by continuously.
What is a commonly known radar?
The area of RADAR and it's applications is very diverse and so are there capabilities and weaknesses, but if someone said to me a common radar I would think of small yacht radar using a Magnetron, Mechanical Scanned printed Antenna FET Receiver and non coherent Pulsed Radar Signal Processing. However it others it might be a FMCW speed control radar used by the police, or a Air Traffic Control radar. What is for sure is it would not be a military radar which are much more advanced and specialised with greater capacities then these RADARs, and therefore cannot be described as common. Perhaps I might add that it might be my view that a common radar has at least two degrees of freedom Azimuth and Range and may not have elevation or Doppler measurements.
Why is Doppler radar important?
Ship use radar for navigation and collision avoidance. The radar set on most board are equip with what is called the ARPA set which are a set of navigation aid that allow ranges baring and content baring to be examined. (when a constant bearing exist am risk of collision exists. Marine radar also allows the establishment of radar tracks to track boat, buoy and land masses. Some radar systems as also equipped transponder modes that work be transmitting on one frequency and listening on another, system such as this are used for Raycon Boys and search and rescue beacons. Marine radar fall into three classes S band 3GHz long range and low weather susceptible, X Band 9.375GHz closer range and can also see rain squalls etc and FMCW wideband radar witch is used for close range low power and port and marine navigation.
What is difference between pulse radar and CW radar?
CW or continuous-wave radar cannot determine range due to the lack of a listening period where the radar signal is silent. Pulse radar has a silent listening period (hence the name pulse radar). Therefore it can determine the range of the object causing the return by counting the elapsed time between transmission and receipt of the echo. The above is not quite correct, Continuous Wave Radar and Pulsed Radar differ by there relationship between the Pulse Width (tau) and the scene size (Swath). CW Radar's determine range by Frequency Modulation (FM) ranging this means that they ramp the RF frequency within the pulse during the transmission and are known as FMCW Radar. Pulsed Radar on the other hand use the pulse timing but can also use the FM Ranging trick to enhanced there signal to noise and reduce there probability of interference or detection/interception. CW radar can deduce range by delaying the transmit signal and mixing it with the receive such that it becomes a homodyne receiver and in such cases it is usual to ramp the RF and perhaps use two aerials rather then just one with a duplexer switch like in a Pulse radar system. Edit- hmm i feel the above answer is bit too complex... i don't think typical person would go as far as concerning FM or Pulse Delay Ranging here's my Answer DIFFERENCES BETWEEN PULSE AND CW RADAR Basis -Transmission Pulse RADAR puts delay between transmitting and receiving periods so the time between transmitted pulse and received pulse is different While CW RADAR, Transmit continuously -Antennas Pulse RADAR may use same antenna for Receiving and Transmitting , when transmitting the receiver is "blanked" and while Receiving the receiver is Activated and transmitter is blanked .. this is done by a device called "Duplexer" CW RADAR typically used 2 Antennas, one for transmit another one to Receive since there are no delay to receive as what usually seen in pulse RADAR -Ranging technique Pulse RADAR may use "Pulse Delay Ranging" to provide Range measurements , Frequency Modulation Ranging may also possible , especially for pulse RADAR that transmit many pulses and have very shot time to "listen" example is FMICW (Frequency Modulated Interrupted Continuous Wave RADAR) While CW RADAR provides Range by means of Doppler based Ranging (FM Ranging)
What are differences between CW radar and pulse radar?
CW Radar or Continues Wave Radar uses a constant transmission and is usually used for angle only tracking and can be combined with a second emission that is pulses or swept to deuce range using and separate antenna (or on a time schedule in some cases). The CW part of a CW Radar reference to the transition duty Ratio and because Dead and Listen time are over lapped they normally have two antennas. FM CW Radar or Frequency Modulated Continues Wave Radar, is similar to the CW set up but the Carrier Radio Frequency is swept, when processed this data can produce range data. Again the Dead and Listen time our overlapped and it is normal for separated antenna to be used. The Frequency sweep is repeated in successive management ion different angles Pulsed Radar Transmits a short pulse rather then continuously like the FMCW Radar or CW Radar and has a short Dead time and long listen time During the dead time when the transmission pulse is emitted the receiver is blanked to protect it, After the pulse has completed transmission the receiver is opened to receive the returns. This means that the receiver and transmission times are mutually exclusive and therefore the same antenna can used for both jobs. As the pulse is short the transmission peak power maybe higher then the CW Power but is present for less time. A Hybrid Radar is ICW or Interrupted Continues Wave (some times called Interrupted Carrier Wave) which is really a pulse radar with a high duty cycle.
Defferential cw radar and pulsed radar?
CW Radar or Continues Wave Radar uses a constant transmission and is usually used for angle only tracking and can be combined with a second emission that is pulses or swept to deuce range using and separate antenna (or on a time schedule in some cases). The CW part of a CW Radar reference to the transition duty Ratio and because Dead and Listen time are over lapped they normally have two antennas. FM CW Radar or Frequency Modulated Continues Wave Radar, is similar to the CW set up but the Carrier Radio Frequency is swept, when processed this data can produce range data. Again the Dead and Listen time our overlapped and it is normal for separated antenna to be used. The Frequency sweep is repeated in successive management ion different angles Pulsed Radar Transmits a short pulse rather then continuously like the FMCW Radar or CW Radar and has a short Dead time and long listen time During the dead time when the transmission pulse is emitted the receiver is blanked to protect it, After the pulse has completed transmission the receiver is opened to receive the returns. This means that the receiver and transmission times are mutually exclusive and therefore the same antenna can used for both jobs. As the pulse is short the transmission peak power maybe higher then the CW Power but is present for less time. A Hybrid Radar is ICW or Interrupted Continues Wave (some times called Interrupted Carrier Wave) which is really a pulse radar with a high duty cycle.
What are the differences between cw radar and fmcw radar?
CW Radar or Continues Wave Radar uses a constant transmission and is usually used for angle only tracking and can be combined with a second emission that is pulses or swept to deuce range using and separate antenna (or on a time schedule in some cases). The CW part of a CW Radar reference to the transition duty Ratio and because Dead and Listen time are over lapped they normally have two antennas. FM CW Radar or Frequency Modulated Continues Wave Radar, is similar to the CW set up but the Carrier Radio Frequency is swept, when processed this data can produce range data. Again the Dead and Listen time our overlapped and it is normal for separated antenna to be used. The Frequency sweep is repeated in successive management ion different angles Pulsed Radar Transmits a short pulse rather then continuously like the FMCW Radar or CW Radar and has a short Dead time and long listen time During the dead time when the transmission pulse is emitted the receiver is blanked to protect it, After the pulse has completed transmission the receiver is opened to receive the returns. This means that the receiver and transmission times are mutually exclusive and therefore the same antenna can used for both jobs. As the pulse is short the transmission peak power maybe higher then the CW Power but is present for less time. I Hybrid Radar is ICW or Interrupted Continues Wave (some times called Interrupted Carrier Wave) which is really a pulse radar with a high duty cycle.
Do cops have radar?
Traffic "Cops" use FMCW radar, as they can be very low power and work off batteries. LADAR is also used and this makes the beam much narrower as the wavelength is higher, it should be more accurate but is more likely to suffer from atmospherics. Yes, for speed metering. Radar can be detected by consume hardware, which is illegal in many states. Most police forces have moved to laser because it is more accurate, is difficult for a speeder to contest in court, and is almost impossible to detect until it's too late.
Is the Doppler radar the only satellite radar in the world?
Actually the Doppler Radar aka nexrad Next generation radar is not a satellite it is a radar. Satellites are floating around the world in space and Doppler radars are here on earth to monitor weather. As far as I know the Doppler radar is the only weather radar in the world. It is basically the only thing used for monitoring weather. I the above is not quite correct. Weather radars come in two basic types coherent and non-coherent. The Coherent radar come in Doppler Radar which can be FMCW or Active Pulse Doppler. The non coherent Pulse Radar merely aim high energy pulses at the clouds and display the returned power in a colour display. The coherent version integrates many pulses together to gain a Higher signal to Noise and to detect water drops moving in clouds. That aside, to answer the question which has nothing to do with weather radar, Doppler radar is frequency used in space verticals because its coherent processing gains in achieves help to offset the ranges it operates over, but it is not the only radar technique to be used on satellites and it depends on what the radar is trying achieve. Note that Doppler radar is non a synonymous exclusively of "nexrad Next generation radar".
Advantages of FMCW altimeter over pulse based altimeter and compare both?
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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.
