[X] My Assistant

[Schillrich]

Hello,

I am from Germany, my name is Daniel and I am new to unmannedspaceflight.com. I have not found a thread about the German TerrarSAR-X (and soon TanDEM-X) mission. So started this thread and plan to give some report about that mission from time to time.

TerraSAR-X was launched in 2007 and circles the earth on a dusk-dawn-orbit at about 514 km altitude. It maps Earth's surface with a phased array X-band SAR-antenna. Soon its twin TanDAM-X will be launched into to almost the same orbit. In their dual mission the 2 satellites will fly as close as 200m for a long duration to produce stereoscopic radar images of the surface.

Here is one recent picture of Earth: Mexico City mapped with 4 months in between:

(DLR): large version


Interesting details are the red marked areas. These areas were lowered by 10cm in 4 months (I think that makes about 4 inch ). The reason behind this is the high water consumption from local wells. The areas without any color overlay could not return useful radar data for this oberservation due to high vegetation density, which changes in itself rapidly.



PS: If I have missed an existing thread ... feel free to relocate this first posting.

[Schillrich]

Hi,

good idea, but unlikely. I doubt that the radar beams of TSX penetrate below the water surface. Otherwise we should see more details of subsurface structures on the pictures. There are other pictures of TSX where water surfaces always appear smooth and dark, explained by uniform radar echoes from the surface itself.
But the idea of an xyz-slide could be the explanation, still. Some strong local displacement, not of the ground as a whole but of surface material, could well account for the "red dots" scattered across the map.