UTM problem

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UTM problem

Werner W.
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



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Re: 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. <[hidden email]> 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

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Re: UTM problem

Werner W.
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




----- Ursprüngliche Mail ----

> Von: Sarah Goslee <[hidden email]>
> An: Werner W. <[hidden email]>
> CC: [hidden email]
> 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.  <[hidden email]>  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
>



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Re: UTM problem

Ageel Ibrahim Bushara
In reply to this post by Werner W.
Hi,

It seems the problem with your data. It seems there is inconsistency in your
data.
Here:  3258843     32780
You have  7 digits for x and 5 digits for y

And here are the coordinates of Kampala: 459199  33160 on WGS84
You have  6 digits for x and 5 digits for y


Ageel





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To: [hidden email]
Sent: Wed, October 13, 2010 3:39:14 PM
Subject: [R-sig-Geo] UTM problem

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Re: UTM problem

Sarah Goslee
In reply to this post by Werner W.
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. <[hidden email]> 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
>
>
>
>
> ----- Ursprüngliche Mail ----
>> Von: Sarah Goslee <[hidden email]>
>> An: Werner W. <[hidden email]>
>> CC: [hidden email]
>> 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.  <[hidden email]>  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

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Re: UTM problem

Werner W.
Many thanks for your replies Ageel and Sarah!
I still have no clue what to do with the data to make it usable.
The northings are in the range of 26237 to 38149 which seem to make sense but
the eastings are in the range of 3252446 to 3264111 and these don't seem to be
in Uganda.
If I use one of these converters, I even get an error message that this data is
not within a given range.
http://geographiclib.sourceforge.net/cgi-bin/GeoConvert?input=29437+3254314&zone=36&prec=0&option=Submit


It is really weird.


Thanks,
  Werner


----- Ursprüngliche Mail ----

> Von: Sarah Goslee <[hidden email]>
> An: Werner W. <[hidden email]>
> CC: [hidden email]
> 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. <[hidden email]>  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
> >
> >
> >
> >
> > ----- Ursprüngliche Mail  ----
> >> Von: Sarah Goslee <[hidden email]>
> >>  An: Werner W. <[hidden email]>
> >>  CC: [hidden email]
> >>  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.  <[hidden email]>  
> 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
>



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Re: UTM problem

Barry Rowlingson
On Wed, Oct 13, 2010 at 4:14 PM, Werner W. <[hidden email]> wrote:

"""
>Coordinates are given as, e.g.
3258843     32780
which are supposedly zone 36N on system WGS84 (according to the documentation).

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.

 """

 Are you sure they are UTM zone coords? Not just plain degrees in EPSG4326?

Maybe your 3258843 is Kampala's 32.633  (32.58843 with no decimal) and
the 32780 is 0.3 (0.32780 with no leading zero or decimal)?

Just a thought.

Barry

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