Subject: What is the difference between SAR, RADAR Interferometry, and InSAR

I have heard the terms Synthetic Aperture RADAR (SAR), RADAR Interferometry, 
and Interferometric Synthetic Aperture RADAR (InSAR).  I understand the basics 
of RADAR, RADIO waves broadcasted by an antenna are reflected off objects and 
picked up by a reciever, allowing distance, direction, and velocity (in the 
case of doppler) to be picked up.  I also know inteferometry and SAR have one 
thing in common, they both use computers to create a "virtual" antenna larger 
than the real antenna or antennas.  I also know SAR only requires one antenna 
(that must move) while interferometry and InSAR both require at least two 
antennas.  But I am not sure how they differ in the processing involved, the 
results that they give, and the uses of the 3 systems.

Re: What is the difference between SAR, RADAR Interferometry, and InSAR