User:Ikonor/DE:CGIAR-CSI SRTM 1/2 Pixel Versatz

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Fragen/Unklarheiten

  • Pixel-Darstellung bei PixelIsPoint? (halbes Pixel verschoben, so dass Rastergitter/Punktkoordinaten in Pixel-Mitte?)
  • ArcASCII corner/center = GeoTIFF PointIsPixel/PointIsArea?
    • CGIAR ArcASCII x/yllcorner vs. GeoTIFF AREA_OR_POINT=Area
  • cgiar.org GeoTIFF 6001 Pixel, in readme.txt aber "All GeoTiffs with 6000 x 6000 pixels"


CGIAR-CSI SRTM 90m v4.1 Downloads

http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp

readme.txt Auszug (in alle Downloads gleich):

Version 4.1 has the following enhancements over V4.0:
- All GeoTiffs with 6000 x 6000 pixels.

ArcASCII

ftp://srtm.csi.cgiar.org/SRTM_v41/SRTM_Data_ArcASCII/srtm_37_05.zip

srtm_37_05.asc Header:

ncols         6001
nrows         6001
xllcorner     -0.00041661826815287
yllcorner     34.999583454375
cellsize      0.00083333333333333
NODATA_value  -9999

"gdalinfo srtm_37_05.asc" Auszug:

Size is 6001, 6001
Origin = (-0.000416618268153,40.000416787708311)

GeoTiff

CGIAR-CSI (USA)

ftp://srtm.csi.cgiar.org/SRTM_V41/SRTM_Data_GeoTiff/srtm_37_05.zip

"gdalinfo srtm_37_05.tif" Auszug:

Size is 6001, 6001
Origin = (-0.000416618268153,40.000416787708332)
Metadata:
  AREA_OR_POINT=Area

JRC (IT)

ftp://xftp.jrc.it/pub/srtmV4/tiff/srtm_37_05.zip

"gdalinfo srtm_37_05.tif" Auszug:

Size is 6000, 6000
Origin = (0.000000000000000,40.000000000000000)
Metadata:
  AREA_OR_POINT=Area

SRTM

USGS GeoTiff

http://earthexplorer.usgs.gov/ "SRTM Void Filled" (90m v2)

"gdalinfo n39_e003_3arc_v2.tif" Auszug:

Size is 1201, 1201
Origin = (2.999583333333333,40.000416666666666)
Metadata:
  AREA_OR_POINT=Point
  DTED_OriginLatitude=0390000N
  DTED_OriginLongitude=0030000E
  DTED_...


PixelIsArea vs. PixelIsPoint

Andere sind auch verwirrt


Sampling vs. Averaging

Versionen und Quellen: