It's a poor hack but it works enough if I can find accurate markers (like junctions in highways) since those should have identical coordinates no matter what software is being used. I only need anchor points, not much else.
--- On Sun, 12/6/09, Gerry Creager <gerry.crea...@tamu.edu> wrote: > From: Gerry Creager <gerry.crea...@tamu.edu> > Subject: Re: [Xastir] More on radar problem > To: "Xastir - APRS client software discussion" <xastir@lists.xastir.org> > Date: Sunday, December 6, 2009, 11:40 PM > I'll find the explicit reference (all > I can find is the full-US mosaic right now) but using > Delorme is a real poor hack since the projections are > different between RIDGE and Street Atlas. At least > from a GIS geek perspective. > > gerry > > James Jolin wrote: > > Alex Carver wrote: > >> --- On Sun, 12/6/09, James Jolin <jjo...@itol.com> > wrote: > >> > >>> Alex, > >>> How did you set up the geo file? Did you > take an > >>> existing file and change the url or did you > start from > >>> scratch? I know next to nothing about > geo files. > >>> Jim > >>> WA9ARB > >>> > >> > >> The easiest way is to follow along with one of the > default GEO files and make the appropriate modifications. > >> > >> Here's an example of my GEO for the Atlanta area > RIDGE radar (watch out for word wraps): > >> > >> # > X > Y > Long > Lat > >> URL http://www.srh.noaa.gov/ridge/RadarImg/N0R/FFC_N0R_0.gif > >> TIEPOINT > 0 > 0 > -87.37500 > 35.58083 > >> TIEPOINT > 620 > 620 > -82.00217 > 31.14133 > >> IMAGESIZE 620 620 > >> REFRESH 60 > >> TRANSPARENT 0x0 > >> PROJECTION LatLon > >> > >> The TIEPOINT directives will assign a specific > pixel coordinate (X,Y) to a specific lat/long. Pixel > 0,0 is upper left, and 620x620 is the lower right most pixel > on my RIDGE image (the image itself is also 620x620 in this > case). You need two TIEPOINTs so that Xastir can > appropriately place the image. The IMAGESIZE tells > Xastir how big the radar file is in pixels (again 620x620 > for the Atlanta RIDGE). > >> > >> After that, just fix the URL accordingly. > >> > >> The more accurate the points, the better the radar > will line up with your maps. I used Delorme Street > Atlas to find a couple known points in the RIDGE data and > then worked my way back to the corners. You don't have > to use the corners of the image file, any two points will do > since Xastir knows about the overall image size using the > IMAGESIZE directive. > >> > >> You may have to play around with the TRANSPARENT > directive which tells Xastir what color is defined to be > transparent for overlay purposes. > >> > >> > >> > _______________________________________________ > >> Xastir mailing list > >> Xastir@lists.xastir.org > >> http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir > >> > >> > > thanks, Alex...looks like a nice evening project. > > Jim > > > > _______________________________________________ > > Xastir mailing list > > Xastir@lists.xastir.org > > http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir > > _______________________________________________ > Xastir mailing list > Xastir@lists.xastir.org > http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir > _______________________________________________ Xastir mailing list Xastir@lists.xastir.org http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir