Michael,
On 11/01/07 16:19, Michael Barton wrote:
Moritz,
I'm afraid there is no FM to R. I've been so pushed to plug all the holes in
making GRASS usable without X11, I just haven't kept up with all the
documentation. I should probably relook at the mouseover help to make sure
it is understandable
I don't think that you should necessarily be the one to do this as well. You have many other things to do, and I think that documentation is the one thing _everyone_ can help with.
Your description below is all I needed (thanks for taking the time), and I think something like this would be enough for most people. Should this go into the gis.m manual page, a separate georectify manual page, or on the WIKI ? I'm willing to format it to whatever is desired.
It is pretty straightforward (IMHO).
It is once you understand it. One of my main problems was that I thought the "ref. map" was what you call the "base map" below, i.e. the one which is already georeferenced. As you can imagine I have problems loading that... 
Another counter-intuitive (for me) feature is the fact that erasing works on the non-selected points. I would have expected the contrary (although I understand the reasoning...).
In terms of comfort, it would be great if the cursor jumped on to the next point after a click on the base map. Now, it automatically jumps to the "geographic coordinates" fields after a click on the reference map, but this does not happen when you click on the base map.
In addition, if you happen to click twice on the base map, the new coordinates get written after those that are already in the "geographic coordinates" field. In my eyes, if you have the cursor in the field and click on the map, the previous coordinates should be erased and the new ones written. This would make it easier if your hand slipped while trying to get a point on the base map.
After having done a georectification, closed the georectifier and then opening it again with a new group to rectify (but from the same origin-mapset), there are (logically) no more coordinates in the georectifier window, but the RMS values from the previous run are still visible. This could be a bit confusion. I would suggest setting them to empty at every new start of the georectifier.
Other than that, easy, fast and efficient !
Moritz
Here are the steps.
Start up in the location you want the new map to be rectified INTO (not the
xy location where it's from).Open any georeferenced map(s), raster or vector, or some combination of
multiple layers in a normal map display to serve as a base map for
georectification.Start the georectifier.
-Decide if you are going to georectify vectors or rasters and check the
appropriate radio button
-Create a group if you don't already have one. This uses i.group for raster
and its own routine for vectors (to create a group folder, etc). All maps
that can be georectified with the same ground control points can go into the
same group
-Select a reference xy map that you can use to set GCP's
-Start georectifyingWhen georectifying, you click on a GCP in the xy map and click on the
corresponding point on the base map. You can also enter coordinates if you
want. You can delete any GCP or exclude from computations. You can check the
RMS error for all active points. This routine bypasses i.points and
i.vpoints to create a points file. The points file can be used for rasters
or vectors, since georectifying of both is supported.When you are ready to georectify the map, pick the polynomial you want to
use (dependent partly on the number of points you have), and press the
button. This will use i.rectify for rasters and v.transform for vectors.
AFAIK, 3rd order polynomial georectification is still broken in i.rectify.
But the rest should work well.The georectified map(s) are projected into your active location/mapset.
Hope this is helpful (and maybe the start of some docs)
MichaelOn 1/11/07 4:18 AM, "Moritz Lennert" <mlennert@club.worldonline.be> wrote:
Hello,
I have some trouble using the georectifying tool in the GIS Manager.
Before asking any questions, I would like to RTFM. Is there any
documentation somewhere ?Moritz
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State Universityphone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton