Manuel, Costa Rica Transverse Mercator is a type of Transverse Mercator (like UTM).
http://www.remotesensing.org/geotiff/proj_list/transverse_mercator.html So we have, in proj.4 notation +proj=tmerc It is revealed here: http://www.asprs.org/resources/GRIDS/04-2008-costarica.pd<http://www.asprs.org/resources/GRIDS/04-2008-costarica.pdf> that the for * "Proyección CRTM90-WGS84" the *central meridian is 84 degrees so we have: +proj=tmerc * +lon_0=-84 * * * * The same author and the document below (a search for "Proyección CRTM90-WGS84" ) * * * *http://www.geotecnologias.com/Documentos/TSCArcGIS_9x.pdf* provide some additional info such that I would think you are probably dealing with : * +proj=tmerc +lon_0=-84 +lat_0=0 +k=0.9996 +datum=WGS84 * Although there might be * CRTM90 projections with a different datum out there. And watch for those false eastings and northings (horizontal and/or vertical shifts to express the coordinates in smaller numbers. (I am assuming + ** x_0=0 +y_0=0 ** ) * http://spatialreference.org/ <http://spatialreference.org/ref/sr-org/6993/> did not have it, but I have uploaded here, so that you can easily test it by clicking on a map: http://spatialreference.org/ref/sr-org/6993/ With this you could try your luck with spTransform Best, Robert On Sat, Oct 16, 2010 at 7:45 AM, Manuel Spínola <mspinol...@gmail.com>wrote: > Thank you very much Alexander. > I am looking at the website right now. > In my case I have a very particular coordinate system (CRTM, Costa Rica > Transverse MErcator) in this case, which parameter I need to know to make > the conversion? > > Best, > > Manuel > > > On 16/10/2010 05:41 a.m., Alexandre Villers wrote: > > Hey Manual, > > One thing to do first would be to ask where you can find the information... > here for example > http://rwiki.sciviews.org/doku.php?id=tips:spatial-data:change_crseverything > you look for is on that page > And have a look a Applied Spatial Data Analysis with R (ASDAR) to > understand the basics of Spatial objects in sp package and how to perform > what you are looking for. It will be much more benefitial for you to learn > it by yourself that simply copy a code one can provide you with... > > HTH > > Best regards > > Alex > > -- > Alexandre Villers, PhD. > Postdoc researcher > Spatial Ecology & Population Dynamics > Section of Ecology, Department of Biology > University of Turku > FIN-20014 Turku > Finland > > @mail: alexandre.vill...@utu.fi > phone: 00358 (0)2 333 5049 > > Skype [image: You can skype me (but think of using Ekiga instead !)] > *Use open source and free softwares* > <http://cran.r-project.org/> <http://grass.itc.it/> > <http://www.qgis.org/> <http://fr.openoffice.org/> > <http://www.mozilla-europe.org/fr/> <http://www.mozilla-europe.org/fr/> > > > _______________________________________________ > R-sig-Geo mailing > listr-sig-...@stat.math.ethz.chhttps://stat.ethz.ch/mailman/listinfo/r-sig-geo > > > > -- > *Manuel Spínola, Ph.D.* > Instituto Internacional en Conservación y Manejo de Vida Silvestre > Universidad Nacional > Apartado 1350-3000 > Heredia > COSTA RICA > mspin...@una.ac.cr > mspinol...@gmail.com > Teléfono: (506) 2277-3598 > Fax: (506) 2237-7036 > Personal website: Lobito de río<https://sites.google.com/site/lobitoderio/> > Institutional website: ICOMVIS <http://www.icomvis.una.ac.cr/> > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > >
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