What is the purpose of quartz delay line in MTI radar?

Early MTI systems generally used an acoustic delay line to store a single pulse of the received signal for exactly the time between broadcasts (the pulse repetition frequency). This stored pulse will be sent to the display along with the next received pulse.

Why is MTI delay line canceller called a time domain filter?

The delay-line canceller acts as a filter which rejects the d-c component of clutter. Because of its periodic nature, the filter also rejects energy in the vicinity of the pulse repetition frequency and its harmonics. It is assumed that the gain through the delay-line canceller is unity.

What is delay line canceller?

Delay line canceller is a filter, which eliminates the DC components of echo signals received from stationary targets. This means, it allows the AC components of echo signals received from non-stationary targets, i.e., moving targets.

What is coho in MTI radar?

COHO, short for Coherent Oscillator, is a technique used with radar systems based on the cavity magnetron to allow them to implement a moving target indicator display. Because the signals are only coherent when received, not transmitted, the concept is also sometimes known as coherent on receive.

What is blind speed in MTI radar?

The blind speed is a radial speed of the airplane at which the phase shifting of the echo-signal has the value ±n · 360° between two pulse periods. With blind speeds moving targets are suppressed by a MTI system like ground clutters.

What is the difference between detectors for coherent and non coherent MTI radar?

In this radar, required variations are obtained by comparing required echoes from stationary and radially moving targets. In non-coherent MTI radar, change in amplitude is considered. As shown, modulated output from magnetron is transmitted. The received echo signal and local oscillator difference is fed to the mixer.

At which frequency the coho in MTI operates?

It does this by tapping off a small amount of the output using a directional coupler, and then feeding that into the first stages of the receiver. This produces an IF signal that contains the precise phase of the broadcast, typically with outputs in the range of 1 to 60 MHz, suitable for storage in a delay line.