NASA, Japan Make ASTER Earth Data Available at No Cost

> Despite the nominal 1" resolution, the true resolution is lower than 3" (downsampled from 1") SRTM data, and there are very many pits, bumps and mole runs. So far the tallest spike that I have found is 3,844 metres, at N 60�43' E 22�02', in south west Finland, and the deepest pit is about 3,000 metres, in tile N27E088, containing cells below 5,300m close to where Kangchenjunga's main summit ridge should rise to 8586m. Generally, artifacts are visible in almost all areas of low relief. Coastlines are not at all accurate; lakes have not been flattened and are particularly badly affected by artifacts. Major errors can be found in most areas of very high relief, But in between, some areas of medium to high relief have been well done and are almost artifact free. My early impression is that, for areas where topographic coverage is poor, these data could be separated out for use to improve DEM data, including both mountain and desert voidfill data, on this and other sites. At one time I thought it may also be possible to flatten the low relief artifacts to provide data that will improve coverage of the plains of North Eurasia, but after further consideration I doubt that this will be possible.