Maptitude - http://research.umbc.edu/~roswell/maptitude.html Hi Peter: This high speed exchange of messages reach me at the moment of struggling with a vector map coordinate transformation, so I am wondering if you can help, please. The problem is the following: 1) I have a vector map (more than 20 layers) that was digitized from several paper sheets, scale 1:250.000 unknown projection. The job started in Microstation, and was imported to Maptitude using 3 Points transformation. The whole map is "slightly" distorted, but that is worst in the West part, (S�o Paulo State is divided into two UTM zones by the 48th Meridian). 2) I have tried to correct the distortion, but it is impossible using just a three point transformation (the only option found in Maptitude and TransCAD). I have a glimpse that I had faced (and solved) that problem before, and checking out the manual of GisPlus version 2.1 (DOS) I have found all my papers solving a similar problem with "Rubbersheeting". 3) I have not found anything like that nor in Maptitude neither in TransCAD manuals (the word Rubbersheeting is not even mentioned!) 4) Any suggestions? I did not check within the interactive Help of TransCAD or Maptitude, neither on GISDK, but I am afraid that the result will be the same... Thank you for the attention. Best regards, and Happy New Year and (this time is true...) Millennium. Reinaldo "Peter H. Van Demark" wrote: > Maptitude - http://research.umbc.edu/~roswell/maptitude.html > > Richard: > > >I think Caliper knows what to do, but my knowledge of projections and > >coordinate systems is just enough to get really flat maps of WA and CA > >looking like a string bean. One of the "bad" things Maptitude does for us > >projection weenies is to make it a bit too transparent (I am not really > >complaining!) so I get a little confused. > > The problem with these data is that the CD contains all of the image and > projection parameters neatly encapsulated in the GeoTIFF file, but the data > on the FTP site require you to hand-build the .HDR file without providing > you with its format! > > (Richard and I have been having an exchange on the side, which should > result in a template for the .HDR file that others can use.) > > >With vector maps you can be blissfully ignorant (not all that bad ..) but > >when the raster world meets the vector world, then you got to have your > >act together or your vector map is one hemisphere and the raster just off > >the coast of Mauritius. > > That is because the vectors are (or can be converted to) > longitude/latitude, which then can be displayed in any > projection/coordinate system that is appropriate. The rasters are images of > the earth that have an inherent projection/coordinate system, and for the > vectors to line up you have to identify that projection/coordinate system. > > Peter > > ---------------------------------------------------------------- > Peter Van Demark > Director of GIS Products and Training Phone: 617-527-4700 > Caliper Corporation Fax: 617-527-5113 > 1172 Beacon Street E-mail: [EMAIL PROTECTED] > Newton MA 02461-9926 Web site: http://www.caliper.com > > ______________________________________________________________________ > To unsubscribe, write to [EMAIL PROTECTED] ______________________________________________________________________ To unsubscribe, write to [EMAIL PROTECTED]
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