The Space Place :: Topo Maps from Space

What Do Topo Maps Have to Do with Space?

We can use a technology called imaging radar to help create a picture of the terrain on Earth--or any other planet. Imaging radar instruments are either flown over the land (or water) in an airplane, flown in space on the Space Shuttle, or put on a spacecraft and launched into orbit around the planet.

SRTM image of islands off Newfoundland

This image was made from Shuttle Radar Topography Mission data. It shows two islands, St. Pierre and Miquelon, near Newfoundland, Canada. Miquelon is in two parts, separated by a narrow strip of beach. Notice that the SRTM data shows the heights of the islands.

The Shuttle Radar Topography Mission (SRTM)

SRTM flying aboard Endeavour was flown aboard the Space Shuttle Endeavour in February 2000. It passed over almost every point on Earth. It made radar images that scientists will use to make the best topo map ever made of Earth. It will take scientists a long time to study all the image data and up to two years to make the map.

SRTM mapping Earth SRTM is actually two radars. They are on opposite ends of a long mast that unfolded from its container in the cargo bay of the Shuttle Endeavour. This structure is the largest ever to fly in space.
Why does SRTM have two radars?
How does imaging radar work?