UTM problem

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

Von: Sarah Goslee <sarah.goslee at gmail.com>
An: Werner W. <pensterfuzzer at yahoo.de>
CC: r-sig-geo at stat.math.ethz.ch
Gesendet: Mittwoch, den 13. Oktober 2010, 14:48:50 Uhr
Betreff: Re: [R-sig-Geo] UTM problem

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 

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

Hi Sarah,

many thanks for checking this. I looked at the documentation again and this is
the info about the GPS receiver setting they used:
POSITION FRMT: hddd.ddddd
MAP DATUM: WGS 84
CDI: +-0.25
UNITS: METRIC
HEADINGS: GRID E000
DEGEES


I'm not sure if this is any useful.
Any idea what I should be looking for?

The survey actually covers the whole of Uganda. Can it actually be that the
entire country is UTM zone 36N or does the zone have to change? The docu
suggests it is all 36N.

Thanks again,
?Werner




----- Urspr?ngliche Mail ----

Von: Sarah Goslee <sarah.goslee at gmail.com>
An: Werner W. <pensterfuzzer at yahoo.de>
CC: r-sig-geo at stat.math.ethz.ch
Gesendet: Mittwoch, den 13. Oktober 2010, 14:48:50 Uhr
Betreff: Re: [R-sig-Geo] UTM problem

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

Von: Sarah Goslee <sarah.goslee at gmail.com>
An: Werner W. <pensterfuzzer at yahoo.de>
CC: r-sig-geo at stat.math.ethz.ch
Gesendet: Mittwoch, den 13. Oktober 2010, 15:24:50 Uhr
Betreff: Re: [R-sig-Geo] UTM problem

It looks like Uganda is mostly but not entirely in 36N. It's possible
the  data switches zones, or that it keeps the same zone throughout
and uses  northing and/or easting values outside the usual range.
Plotting the entire  dataset as x, y coordinates would answer that
question very  quickly.

Here's some more information:
http://commons.wikimedia.org/wiki/File:LA2-Africa-UTM-zones.png
http://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system

Sarah

On  Wed, Oct 13, 2010 at 10:08 AM, Werner W. <pensterfuzzer at yahoo.de>  wrote:

Hi Sarah,

many thanks for checking this. I looked  at the documentation again and this 

is

the info about the GPS receiver  setting they used:
POSITION FRMT: hddd.ddddd
MAP DATUM: WGS  84
CDI: +-0.25
UNITS: METRIC
HEADINGS: GRID E000
 DEGEES


I'm not sure if this is any useful.
Any  idea what I should be looking for?

The survey actually covers  the whole of Uganda. Can it actually be that the
entire country is UTM  zone 36N or does the zone have to change? The docu
suggests it is all  36N.

Thanks again,
  Werner




----- Urspr?ngliche Mail  ----

Von: Sarah Goslee <sarah.goslee at gmail.com>
 An: Werner W. <pensterfuzzer at yahoo.de>
 CC: r-sig-geo at stat.math.ethz.ch
 Gesendet: Mittwoch, den 13. Oktober 2010, 14:48:50 Uhr
Betreff: Re:  [R-sig-Geo] UTM problem

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

Coordinates are given as, e.g.