[GRASS-user] howto make my srtm-dem jump the GIS gap

[Rudolf Maurer]

Hi there!

I tried Williams
r.out.gdal in=dem out=dem.tif cre="COMPRESS=PACKBITS" type=Int16
which looks OK:
GRASS 6.0.1 (baydem):~ > r.out.gdal in=clean_alle out=clean_test.tif
cre="COMPRESS=PACKBITS" type=Int16
Writing format: GTiff
Writing type:   Int16
Input file size is 2400, 2400
0.Warning 1: Unable to export color table to GeoTIFF file.  Color tables
can only be written to 1 band Byte or UInt16 GeoTIFF files.
..10...20...30...40...50...60...70...80...90...100 - done.

Even though I used d.what.rast to check on the data-format, and I got
floating point numbers (I guess due to interpolation):
10:48:07.5E 47:01:22.5N
clean_alle in maurerr, quant   (2686)
clean_alle in maurerr, actual  (2685.749512)
What's the difference between those two values? What would be the
common way to get this information?

TIF is 12MB. My QGIS 0.7.4 "Seamus" does have problems opening it...
Tomorrow I can check what E$SRI says.

> That is a good point. The 2 Gb limit is still a problem for file-based data in ArcGIS. Rudolf, is your file around 2 Gb?

Definitely not: ARC-Grids have under 30MB. I use 4 tiles of SRTM-Data,
2400 by 2400 cells in 9 arc seconds.

Now Arc-Grid:
I did
GRASS 6.0.1 (baydem):~ > r.out.gdal in=clean_alle out=clean_test_arc
type=Byte format=AAIGrid
Writing format: AAIGrid
Writing type:   Byte
Input file size is 2400, 2400
0...10...20...30...40...50...60...70...80...90...100 - done.

File is 26 MB.
Is type=Byte OK? I would not need big numbers though.

I will report back to you.

Many thanks,
Rudy