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3

Given your error, my guess is that when you are importing the file to GRASS, it is expecting a GRASS ASCII raster format, which has a header that looks like this: north: ####.### south: ####.### east: ####.### west: ####.### rows: ####.### cols: ####.### Instead of an ArcGIS ASCII grid, which has a header that looks like ...


2

If you don't know the extent in coordinates of the prj file, you have to georeference the file manually using ground control points. This is rather comfortable if you have QGIS installed, and you can guess some details from the image. In some cases, you can build the extent manually if the filename follows a certain rule, like the one-degree-SRTM files do. ...


2

Here is the source to the underlying Java library, prj2epsg, used behind the scenes on the webpage you list. Basically, it uses a Lucene index to get the best match between the WKT in your prj file and an underlying EPSG. As AndreJ has already said, this may not be 100% perfect, but Lucene excels at partial/fuzzy matching. gdalsrsinfo might be easier to get ...


2

There is no such tool working 100% perfectly, because there are many EPSG codes that share the same projection parameters. You can run gdalsrsinfo on any Geotiff or shapefile .prj file to get the proj string out of the definition. For some intelligent ways of guessing, follow the answers given here: Identifying Coordinate System of Shapefile when Unknown? ...


2

It's highly inefficient to merge mosaic using gdal merge. Instead, make a VRT (Virtual Dataset) and convert it to your favourite format.


2

With libtiff you can't get altitude from you file. I spent a lot of time trying to do it with libgeotiff. My advice is to install GDAL. Example: GDALRasterIO( hBand_ , GF_Read , p, l, 1, 1, &pafScanline, 1, 1, GDT_Float32, 0, 0 );


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I am fairly sure that the error is associated with the FUN argument. R is case sensitive and the argument in extract is lowercase "fun". To understand how this works I would break down the components of the analysis rather than letting the extract function do all the heavy lifting. Understanding the specific components, in particular the resulting list ...


1

In GRASS GIS, use r.in.arc for the import or simply r.in.gdal (Menu: File -> Import raster data -> Common formats import). This should read the file right away.


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Install OpenJUMP and study what all has been gathered into it I have never really understood what all the alternatives are. ImageIO-ext is probably utilising native GDAL binaries if such are available but at least most other alternatives are pure java. There is also one more alternative in OpenJUMP called "Sextante raster" which is also pure java. ...


1

Under Settings -> Options, CRS tab, enable Prompt for CRS for new layers. Then you will be asked explicitely for the CRS, which should be the same as you georeferenced to in Arcgis. You might get a datum shift of up to 100m, as this is not stored by Arcgis. But QGIS has bundled the shift with the common projection definitions.



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