I've heard rumors that these radar images penetrate water. And that's their primary usefullness. Shows submarines in the water (ever wonder why we decommissioned SOSUS?). Shows wrecks on the bottom (ever wonder how its been so easy for some people to find specific wrecks lost for decades in the open ocean - hint - sonar hasn't improved that much).
Sure would like to see the original image.
I don't know much about the SRTM, but since the water looks very flat, they may not have done anything with radar returns over water and simply analyzed the land data. (The Canadian RADARSAT gets the best radar data over the ocean for waves and ice.)
The data is collected by scanning the earth's surface to produce a "grid" of values that are then converted to the image you see by combining information (e.g. slope, aspect, elevation) to produce an idealized view of the surface.
Because the large water bodies have "zero" elevation and are essentially "flat" they are assigned a consistent color. Thus they appear unrealistic because there is no natural variation in shade. Because I have some experience in this, it is obvious that the whole thing is "unrealistic", but it is a beautiful image nonetheless.
The global digital elevation dataset that came from this program is a gold mine for those in geospatial data analysis fields.
The description (especially the last paragraph) is quite accurate.
Russ
LIDAR systems (that use active laser ranging) get about 3-meters of penetration in non-turbid water and has proved useful for characterizing the underwater surfaces nearshore.
Russ