Oon:<br> My sugestion:<br> 1) Convert to degrees<br> 2) Calculate distance with a geodesic algorithm (Vicenthy, Puissant, etc).<br><br> You can't use this distance to irradiate new UTM points (distance + angle + source point = second point) because UTM distance are "projected" (with controled distortion). To make this you must project this distance with local + ellipsoid parameters.
<br><br>I Don't know about distance calculation with proj4 tools<br>There is manual methods to "zone transposition", but my sugestion is more simple and generic than it.<br><br>When you talk about WGS84 you talk about "datum", not "projection". UTM is used too with WGS84 datum.
<br>You only calculate distance with cartesian formula using latlong coordinates with you don't care about hundred meters of error but if you dont care about probaly you are talking about much kilometers, than maybe you get thousand meters of erros using this.
<br><br><br>Regards<br>-- <br>Marco Vieira<br>+55 21 9499-6800<br>e-mail: <a href="mailto:maovieira@gmail.com">maovieira@gmail.com</a>
<br><br><div><span class="gmail_quote">2006/9/13, <a href="mailto:oon@informatika.org">oon@informatika.org</a> <<a href="mailto:oon@informatika.org">oon@informatika.org</a>>:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br> Dear All,<br><br>I want to ask a question about distance calculation of two points in<br>X,Y (UTM).<br>Is it ok if I get the distance of two points in X,Y (UTM) only with distance<br>calculation of cartesian coordinate (pythagoras method)?
<br>The error getting larger (or getting huge) if I calculate the distance<br>with the<br>points crossing the UTM zone. (I have tried for point with (1) different zone,<br>I don't know what will be happened if the points over more than 1 zone??)
<br><br>Is it any other method to get distance calculation of cartesian<br>coordinates X,Y (UTM), so the result of the calculation have accuracy<br>like distance calculation<br>of WGS84?<br>(It's ok if the error about hundred meters)
<br><br>thanks for your help..<br><br>--<br>regards,<br>Oon Arfiandwi<br>Software Engineer<br>Bandung, Indonesia.<br><br><br>_______________________________________________<br>Proj mailing list<br><a href="mailto:Proj@lists.maptools.org">
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