[R-sig-Geo] UTM problem

[Sarah Goslee]

Hi,

I double-checked your results with an online conversion tool
(http://www.rcn.montana.edu/resources/tools/coordinates.aspx)
and got the same answer.

That means that your R code is fine, and there's something
wrong with the original data. If possible, you should check with
the source. There could be a problem with the metadata, or
with the data themselves.

Sarah

On Wed, Oct 13, 2010 at 9:37 AM, Werner W. <pensterfuzzer at yahoo.de> wrote:
> Hi,
>
> this questions is not really about R but it would be great if somebody could
> point me to a forum or so where I can get help with this.
>
> I only know a few basics about GIS and have a problem with some UTM coordinates
> from a survey.
> Coordinates are given as, e.g.
> 3258843     32780
> which are supposedly zone 36N on system WGS84 (according to the documentation).
> If I convert it to long/lat using gdal:
>> require(rgdal)
>> SP <- SpatialPoints(cbind(X=3258843, Y=32780),proj4string=CRS("+proj=utm
>>+zone=36 +ellps=WGS84"))
>> spTransform(SP, CRS("+proj=longlat +ellps=WGS84")) # x1=longitude x2=lat
> SpatialPoints:
>           X         Y
> [1,] 57.0489 0.2706471
> Coordinate Reference System (CRS) arguments: +proj=longlat +ellps=WGS84
>
> The point should be close to Kampala which has the coordinates 0.3°, 32.633333°
> and UTM 36N 459199 33160 on WGS84. My data's easting seems quite off.
>
> Has anybody an idea what I am doing wrongly?
>
> Thanks so much,
>  Werner
>
>
>


-- 
Sarah Goslee
http://www.functionaldiversity.org