Radar used to eliminate clutter in navigational application is:

MTI (Moving Target Indication) radar is specifically designed to filter out stationary clutter (buildings, terrain, rain) and detect only moving targets by exploiting the Doppler shift. It uses phase memory from successive pulses to cancel stationary returns. Pulse radar is generic and doesn't address clutter; tracking radar follows known targets; mono pulse radar improves angular accuracy but doesn't eliminate clutter.

Step-by-step Derivation:
Clutter elimination in radar requires discrimination between moving and stationary reflections. MTI radar achieves this by: (1) transmitting pulses at known intervals, (2) storing phase information from each pulse return, (3) subtracting consecutive returns—stationary echoes (zero Doppler shift) cancel out while moving targets produce phase differences that survive the subtraction. This is the standard technique used in navigational and weather radar systems to improve target visibility.