Franz wrote: > I have been using MODIS datasets in MRT tool and MATLAB but Now I > want to import MODIS projected datasets to GRASS . > > At http://grass.osgeo.org/wiki/MODIS > is described methods to do this.
Markus answered most of these, but I'll throw in another 2c. > Question 1: can those methods be applied using a GRASS Script? > (I believe so) (yes) > Question 2: in method 1 (http://grass.osgeo.org/wiki/MODIS#Method_1), > It’s said to create a Project/mapset with EPSG 3266. Why that system? > And Why if gdal_translate will create geotiff in EPSG4326? It says you might try that, not that you definitely should. EPSG:32662 is "Plate Carree" # WGS 84 / Plate Carree <32662> +proj=eqc +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_ defs <> A number of global datasets ship in this. With ~4km pixels a possible datum error of 150m away from the wgs84 DATUM isn't going to be very noticeable. but a switch between the wgs84 ELLIPSOID and a perfect sphere can lead to errors of ~25km. Consult your metadata. Hopefully it gives some guidance (often it doesn't though, hence the confusion). > Question 3: > Regarding a_ullr. This flag asks for Upperleft and lowerright. This > means that those values are the same for all files. But in the case > that they may vary. How can I obtain them from MODIS Metadata/header? > And this would mean that the we are dealing with a regular dataset > because in a Geostationary dataset this wouldn’t be possible (I guess). parse gdalinfo or as Markus suggested the associated XML file?) > Question 4: > What is the –co flag? I read Gdal_translate description > but I didn’t find it very clear.. see the r.out.gdal help page for more on compression. > Question 7: if we define > a_ullr, this means that GCP points are > not being used right? if gdalinfo can see GCPs but not map bounds, use 'gdalwarp -tps' to apply the GCPs and make a georeferenced image which can be loaded into grass. > Regarding method 2, that > is based on GRASS6.5, will this be > implemented for grass 6.4? (the –i > flag) if no problems are reported in testing it will be backported to 6.4.1. Hamish _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
