Global datasets

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Revision as of 07:27, 20 October 2008 by ⚠️HamishBowman (talk | contribs) (→‎LANDSAT: yay free data)
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Blue Marble imagery

NASA's Blue Marble is a 500m-8 degree per-cell world wide visual image of the Earth from space, with the clouds removed.

ETOPO

The ETOPO datasets provide global topography and bathymetry at 1', 2', and 5' per-cell resolutions.

ETOPO1

The cell registered version can be loaded directly into a lat/lon region. GRASS raster data is cell registered (see the GRASS raster semantics page)


The grid registered version must be loaded into a simple XY location using the parameters found in the .hdr file, and needs to have the 90deg N,S rows cropped away:

# create a new simple XY location and mapset

# Import grid registered binary float
r.in.bin -f in=etopo1_bed_g.flt out=etopo1_bed_g \
   n=90.008333333335 s=-90.008333333335 e=180.00833333334 \
   w=-180.00833333334 rows=10801 cols=21601 anull=-9999
r.colors out=etopo1_bed_g color=etopo2

# reduce region by 1 cell
g.region rast=etopo1_bed_g
eval `g.region -g`
g.region n=n-$nsres s=s+$nsres e=e-$ewres -p

# save smaller raster and remove original
r.mapcalc "etopo1_bed_g.crop = etopo1_bed_g"
g.remove etopo1_bed_g

# change the location to lat/lon by restarting GRASS
#  in the PERMANENT mapset and running g.setproj
#  or move the entire mapset into a lat/lon location
#  and manually edit the $MAPSET/cellhd/ files (dirty!)

ETOPO2

ETOPO2v2 data download

GEBCO

  • The General Bathymetric Chart of the Oceans
http://www.gebco.net/data_and_products/gridded_bathymetry_data/

Miscellaneous

  • The r.in.gdal modules may be used to import data of many formats, including GMT netCDF
  • The r.in.bin module may be used to import raw binary files

LANDSAT

Since October 1, 2008 all Landsat 7 ETM+ scenes held in the USGS EROS archive are available for download at no charge.

  • Download via the Glovis online search tool (req. Java)
  • Download via the USGS's EarthExplorer interface

Modules

  • r.in.gdal - Main import tool for complete multiband scenes
  • r.in.wms - Download data covering current map region via WMS server
  • r.in.onearth - WMS frontend for NASA's OnEarth Global Landsat Mosaic
  • i.landsat.rgb - Color balancing/enhancement tool

MODIS

Pathfinder AVHRR SST

merge that info here?

QuickBird

SeaWiFS

merge that info here?

Smith and Sandwell

SRTM


VMap0

1:1 million vector data. Formerly known as Digital Chart of the World