[GRASS-user] exotic datum creation

[Wolfgang]

Hi,

I found some dx,dy,dz values on the net. But now I have an other 
question: I want to calibrate a scanned map. The grid on the map is in 
this Laos Datum, but finally I want to have it wgs84. Do I really have 
to go the way: xy->lao97->wgs84?

Thanks
Wolfgang

Wolfgang schrieb:
> Hi,
> 
> sorry that this is not completely grass related but I wan't to create a 
> location in the 'Laos National Datum 1997'. All information I have is 
> from http://ocean.csl.co.uk/ and is listed below.
> 
> I hope somebody can help me.
> 
> Thanks
> Wolfgang
> 
> datum_code=    6678 (Lao National Datum 1997)
> datum_name=    Lao National Datum 1997
> datum_type=    geodetic
> origin_description=    Fundamental point: Vientiane (Nongteng) Astro 
> Pillar. Latitude: 18 deg 01 min 31.3480 sec N; Longitude: 102 deg 30 min 
> 57.1376 sec E (of Greenwich).
> realization_epoch=    1997
> ellipsoid_code=    7024 (Krassowsky 1940)
> prime_meridian_code=    8901 (Greenwich)
> area_of_use_code=    1138 (Lao People's Democratic Republic (Laos).)
> datum_scope=    Cadastre, topographic mapping, engineering survey.
> remarks=    Supersedes Lao 1993.
> information_source=    National Geographic Department
> data_source=    EPSG
> revision_date=    2004-04-27
> change_id=   
> deprecated=    0
> 
> 6678,Lao National Datum 1997,geodetic,"Fundamental point: Vientiane 
> (Nongteng) Astro Pillar. Latitude: 18 deg 01 min 31.3480 sec N; 
> Longitude: 102 deg 30 min 57.1376 sec E (of 
> Greenwich).",1997,7024,8901,1138,"Cadastre, topographic mapping, 
> engineering survey.",Supersedes Lao 1993.,National Geographic 
> Department,EPSG,2004-04-27,,0,
> 
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