Question

What is Radar Interferometry and how does it work?

Answer 1

RAdio Detection And Ranging (Radar) is a system which uses microwave signals to detect the presence of an object and its properties. Pulses of radio waves are sent from the radar antenna towards the objects. The objects scatter back a part of this energy falling on them, which are collected at the same radar platform. Energy reflected from the terrain to the radar antenna is called radar return.

When an object scatters the radar signal, the scattered signals differ from the original in amplitude, polarization and phase. Thus, the radar information consist complex information in terms of both amplitude and phase of the signals. The difference between the pulses sent and received indicates the properties of the object and the distance of the object.
Principles of radar interferometry are used in the radar remote sensing to generate high resolution DEMs with near global coverage.