Hello. I need to learn how to use GIS and I have chosen to do it with GRASS. My plan is to learn GIS/GRASS essentials during the next 12 months and start applying it for my research the 12 months after that. I have started reading the documentation available and playing with the sample data set. However, I would also like to start playing with a dataset for Puerto Rico (PR) and I am having problems to import it. How would I go about importing a new dataset?
In particular, there is a landcover raster image in Erdas "img" format (prgap_landcover.img) that I would like to import from here: ftp://ftp.gap.uidaho.edu/products/Puerto_Rico/GISdata/Landcover/1_Land_cover_grid/ (1) What do I do with this img file? Do I first copy and paste it to my GIS Data Directory? If not, how do I go about telling GRASS where this file is (if I want to import it)? (2) I read about the commands to import raster Erdas/IMG files to GRASS (r.in.gdal -e in=<image.img> out=<image>). If I want to use this command, should my img file be in the GIS Data Directory first as I suggested in (1)? Where do I type this command? The GRASS Command Line window seems to open for an existing Location. (3) When do I create the location for my data? Do I do this before anything else? (4) When trying to create a location from the Location Wizard, I chose as the method "Select coordinate system parameters from a list". I did this because there is another file in the above mentioned ftp folder with several parameters which seem to me the kind of information that the wizard asks (see an excerpt below). From there I chose "lcc" as the projection code. However, from here onwards I start having problems. For instance, I don't know whether to choose "Datum with associated ellipsoid" or "Ellipsoid only". Also, the wizard asks me "Central Parallel", "First Standard Parallel", "Second Standard Parallel", and I don't know how that relates to the two "Standard_Parallel" parameters given below and where do I get the other "Parallel" parameter from? I seem to be missing one. For the geodetic datum I think I have to choose "nad83" and I think I will choose "No transformation" at the end of the wizard. Any suggestions will be very welcome. Thank you in advance. Saludos, Julio. Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Lambert Conformal Conic Lambert_Conformal_Conic: Standard_Parallel: 18.033333 Standard_Parallel: 18.433333 Longitude_of_Central_Meridian: -66.433333 Latitude_of_Projection_Origin: 17.833333 False_Easting: 200000.000000 False_Northing: 200000.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 15 Ordinate_Resolution: 15 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
