[OSGeo Africa] Identify coordinate system

[Zoltan Szecsei]

Hmmm....Ja.
But querying the source of the data might save all of us from getting a 
hard-earned 'Sherlock Holmes' badge :-)

On 2019/07/12 10:02, Hermanus Brynard wrote:
> Zoltan
> You mention 500k makes me think there could be a UTM transformation 
> which usully adds a 500000m easting or westing and 10 000 000m 
> northing to avoid negative numbers.
>
> Can you send me the shapefile.
> Manie
>
>
> On Fri, Jul 12, 2019 at 8:57 AM Zoltan Szecsei <zoltans at geograph.co.za 
> <mailto:zoltans at geograph.co.za>> wrote:
>
>     Hi Manie,
>     Thanks for the idea.
>
>     The current system in use is QND95 - the one you are suggesting 
>     (I see) is from 1976, and its origin is "too close".
>     (Yes, I still tried it)
>
>     Looking at the numeric values of the coords, I am expecting
>     something with an origin some 500Km West of Doha, and on the Equator.
>
>     And then of course I also need to consider the possibility that
>     the coords in the shapefile are non-sensical, so I'm trying to
>     find out its source....
>
>
>     Thanks and keep well,
>     Zoltan
>
>     On 2019/07/12 09:23, Hermanus Brynard wrote:
>>     Zoltan
>>     Have you tired the
>>
>>     Quatar National Grid <https://epsg.io/28600>
>>
>>
>>         EPSG:28600 <https://epsg.io/28600>
>>
>>
>>     Manie Brynard
>>
>>     On Thu, Jul 11, 2019 at 6:33 PM Zoltan Szecsei
>>     <zoltans at geograph.co.za <mailto:zoltans at geograph.co.za>> wrote:
>>
>>         Hi Listers,
>>         I've been asked o help a school-going daughter of a friend of
>>         mine in Doha (yes, this is "AfricaList" :-/  )
>>         She has been given a shapefile without a projection file. The
>>         area is Al Wakrah, just South of Doha airport.
>>
>>         The numeric values of the geometry coords are around 560000,
>>         2782000 - the second value looked like a distance from the
>>         Equator, so I tried UTM 39N
>>         The scaling seems wrong, and it does not align with the
>>         coastline (QND95) shapefile I have.
>>         (I also tried EPSG:27039)
>>
>>
>>         As you can see, projection-sleuthing is not one of my strengths.
>>         Can anyone point me in a direction to try and solve this?
>>
>>         Thanks in advance.
>>
>>         Kind regards,
>>         Zoltan
>>
>>
>>         -- 
>>
>>         =============================================
>>         Zoltan Szecsei GPrGISc 0031
>>         Geograph (Pty) Ltd.
>>         GIS and Photogrammetric Services
>>
>>         P.O. Box 7, Muizenberg 7950, South Africa.
>>
>>         Mobile: +27-83-6004028
>>         Qatar:  +974 5083 2722www.geograph.co.za  <http://www.geograph.co.za>
>>         =============================================
>>
>>         _______________________________________________
>>         Africa mailing list
>>         Africa at lists.osgeo.org <mailto:Africa at lists.osgeo.org>
>>         You can UNSUBSCRIBE at
>>         https://lists.osgeo.org/mailman/listinfo/africa
>>
>>
>>     _______________________________________________
>>     Africa mailing list
>>     Africa at lists.osgeo.org  <mailto:Africa at lists.osgeo.org>
>>     You can UNSUBSCRIBE athttps://lists.osgeo.org/mailman/listinfo/africa
>
>     -- 
>
>     =============================================
>     Zoltan Szecsei GPrGISc 0031
>     Geograph (Pty) Ltd.
>     GIS and Photogrammetric Services
>
>     P.O. Box 7, Muizenberg 7950, South Africa.
>
>     Mobile: +27-83-6004028
>     Qatar:  +974 5083 2722www.geograph.co.za  <http://www.geograph.co.za>
>     =============================================
>
>     _______________________________________________
>     Africa mailing list
>     Africa at lists.osgeo.org <mailto:Africa at lists.osgeo.org>
>     You can UNSUBSCRIBE at https://lists.osgeo.org/mailman/listinfo/africa
>
>
> _______________________________________________
> Africa mailing list
> Africa at lists.osgeo.org
> You can UNSUBSCRIBE at https://lists.osgeo.org/mailman/listinfo/africa

-- 

=============================================
Zoltan Szecsei GPrGISc 0031
Geograph (Pty) Ltd.
GIS and Photogrammetric Services

P.O. Box 7, Muizenberg 7950, South Africa.

Mobile: +27-83-6004028
Qatar:  +974 5083 2722     www.geograph.co.za
=============================================

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/africa/attachments/20190712/2fa2de3e/attachment-0001.html>