MTI (Moving Target Indicator) works by differentiating between stationary and moving objects in the radar’s field of view. It does this by comparing the radar signals returned on successive pulses. Stationary objects produce consistent signals over time, while moving objects cause changes in the phase or frequency of the signals returned due to their movement.
By analyzing these changes, the MTI system can detect and highlight moving targets in a background of stationary objects.
The principle of MTI is based on the Doppler effect, which is the change in frequency or phase of a wave relative to an observer moving relative to the source of the wave. In MTI, radar pulses are transmitted and echoes from stationary objects have a constant frequency. However, echoes from moving objects experience a frequency shift proportional to their speed relative to the radar.
By detecting this frequency shift, MTI systems can distinguish moving targets from stationary items.
An MTI filter works by processing radar returns to improve detection of moving targets while removing signals from stationary objects. This is usually done using a cancellation technique, where the received signal from one pulse is subtracted from the received signal from a subsequent pulse. If the target is stationary, the signals will cancel each other out.
If the target moves, the signals will not completely cancel out due to Doppler shift, allowing the moving target to be detected.
The difference between Doppler radar and MTI lies in their primary functions and methods of operation. Doppler radar measures the speed of a target by detecting the frequency shift caused by the movement of the target relative to the radar. It provides accurate information about the speed and direction of moving objects. MTI, on the other hand, focuses on detecting and highlighting moving targets in a context of stationary objects.
Although both use the Doppler effect, MTI is specifically designed to filter out stationary clutter and focus on moving targets, while Doppler radar provides detailed velocity information of targets