Re: Fw: [GRASSLIST:8574] [tom.farr JPL.NASA.GOV: SRTM V2 released]

On Tuesday 11 October 2005 21:45, Curtis L. Olson wrote:
> Hamish attached:
> > NASA has released version 2 of the Shuttle Radar Topography Mission
> > digital topographic data (also known as the "finished" version).
> > Version 2 is the result of a substantial editing effort by the
> > National Geospatial Intelligence Agency and exhibits well-defined
> > water bodies and coastlines and the absence of spikes and wells
> > (single pixel errors), although some areas of missing data ('voids')
> > are still present. The Version 2 directory also contains the vector
> > coastline mask derived by NGA during the editing, called the SRTM
> > Water Body Data (SWBD), in ESRI Shapefile format.
> >
> > The data may be obtained by anonymous ftp to:  e0srp01u.ecs.nasa.gov
> > and moving to the directory srtm where both version 1 and version 2
> > directories may be found. Please read the appropriate documentation,
> > also found in the directories.
>
> Thanks, I am starting to fetch the data now ... but it will probably
> take a few days to get it all down here.
>
> The water body data looks interesting.  Is there any word/comments on
> how well this handles lake and river data?  Has anyone commented on how
> the SWBD data might compare to VMAP0?  Having good water body, river,
> and stream data that is calibrated to the underlying terrain data set
> would be a huge gift to the world.  But if this is all generated from
> 30/90 meter elevation posts, I suspect that vmap0 might have finer
> grained resolution?

FWIW - I'm using some of this data in another simulator product and it's still 
far from perfect.
I still see huge amounts of null data in mountainous regions so I use CGIAR's 
SRTM 3 data to fill in the voids in the "finished" SRTM 3 data.

However there is a small but noticeable improvement in in the flattening of 
inland water bodies. Water doesn't tend to ride up on the terrain as much as 
before. It's still far from perfect but every little bit helps.

Regards
Paul

_______________________________________________
Terragear-devel mailing list
[email protected]
http://mail.flightgear.org/mailman/listinfo/terragear-devel
2f585eeea02e2c79d7b1d8c4963bae2d