TOPSAR Intro

RADAR IMAGES OF HAWAII

Radar Topographic Mapping with TOPSAR

TOPSAR is an interferometric radar system that is flown on the NASA DC-8 aircraft. In one flight of the plane, TOPSAR can produce a digital topographic map because the radar has two separate antennas. These antennas allow the phase difference between the radar returns to be measured across a known baseline.

We have prepared a number of maps of Oahu and the Big Island using TOPSAR data. These maps are called "shaded relief maps", because they have been prepared using a computer that simulates a Sun illumination direction and azimuth over the landscape. This technique is particularly helpful for studying subtle relief features, as well as viewing the landscape with illumination directions that we can never get in real life -- such as the Sun shining from the north or south!

Click here for TOPSAR images of SE Oahu

Click here for TOPSAR images of the Big Island