How multiple frequency CW radar can be used to measure the range of a moving target?

CW radar can measure the instantaneous rate-of-change in the target’s range. This is accomplished by a direct measurement of the Doppler shift of the returned signal. The Doppler shift is a change in the frequency of the electromagnetic wave caused by motion of the transmitter, target or both.

What is the difference between Fmcw and pulse radar?

With FMCW technology, the transmitter emits a continous signal and determines the distance to the target by measuring the frequency difference between the emitted and the reflected signals. With pulse radar, the transmitter sends a pulse and then stops and waits for a reflection.

Is its ability to distinguish between targets that are very close together in either range or bearing?

Range resolution
Range resolution is the ability of a radar system to distinguish between two or more targets on the same bearing but at different ranges.

How does a pulse radar work?

A pulse-Doppler radar is a radar system that determines the range to a target using pulse-timing techniques, and uses the Doppler effect of the returned signal to determine the target object’s velocity. This gives pulse-Doppler radars “look-down/shoot-down” capability.

Is FM CW radar is best for the range and Doppler measurement?

The CW radar can measure the Doppler frequency of the target, but it cannot measure the target range. The frequency-modulated CW radar (FM–CW) can measure both the range and Doppler frequency of the target.

How the inability of simple CW radar to measure range can be overcome?

One of the greatest shortcomings of the simple CW radar is its inability to obtain a measurement of range. This limitation can be overcome by modulating the CW carrier, as in the frequency-modulated radar.

How does MTI radar differ from pulse Doppler radar?

The MTI radar has a pulse repetition frequency low enough to not have any range ambiguities. It does however have many ambiguities in the Doppler domain. The pulse Doppler radar, on the other hand, is just the opposite. It has a prf large enough to avoid Doppler ambiguities, but it can have numerous range ambiguities.

How will you determine if the radar is accurate?

The performance of a radar system can be judged by the following: (1) the maximum range at which it can see a target of a specified size, (2) the accuracy of its measurement of target location in range and angle, (3) its ability to distinguish one target from another, (4) its ability to detect the desired target echo …

What kind of radar pulse would give more accurate range and bearing of the target?

short radar pulses
However, short radar pulses generally allow more easy and accurate determination of the range of a target, and also permit two targets closely spaced in range and at the same bearing to be displayed as separate targets. This is known as range discrimination, see Figure 2.3.

What is multi mode radar?

A radar designed to operate in more than one mode with quick switching between these modes (e.g., air-to-air, air-to-ground, air-to-sea, terrain-following, or mapping mode).

How do you determine the range of a bistatic radar?

As with monostatic radars, the target range can be deduced from the time delay incurred between the transmission and reception of the radar pulse. For the bistatic radar illustrated in Figure 1.9, the transmitter and receiver are the foci of an ellipse and the equal time-delay contours form ellipses with the same foci.

What is a monostatic pulse radar?

A monostatic pulse radar, in addition to the compact design has the advantage that the important for pulse radars timing devices can be concentrated in a central synchronization block . Internal runtimes of the radar triggers can thus be kept low. An elaborate radar antenna can be used by means of a multiplexer for both transmitting and receiving.

What are the characteristics of radar pulse modulation?

This method is characterized by radar pulse modulation with very short transmission pulses (typically transmit pulse durations of τ ≈ 0.1 … 1 µs ). Between the transmit pulses are very large pulse pauses Τ >> τ , which are referred to as the receiving time (typically Τ ≈ 1 ms) as shown in Figure 2.

What is the difference between a continuous wave and a pulse radar?

Pulse radar emits short and powerful pulses and in the silent period receives the echo signals. In contrast to the continuous wave radar , the transmitter is turned off before the measurement is finished.