4 replies to this topic

[mhampson4]

Hi
I have been trying endlessly to convert stereographic co-ordinates of hungary to E.O.V. which I think are from the Budapest System datum, as I know they are from the 19 60's 70's and this datum was the last stereographic system used in Hungary (They only state they are hungarian and stereographic).

I think I have a methodology to do this by first converting to Lat/Long using page 62 of this:
http://www.epsg.org/...s/docs/G7-2.pdf

However I do not know the exact parameters of the Budapest system, namely the scale factor.

Could anyone help me? first to determine whether I am correct in saying it is the Budapest system and with any information on the Budapest System.

Thankyou
M.Hampson

P.S. they are none military co-ordinates (Well locations for mining etc.)

[kay]

I am not an expert in the Hungarian CS but I found one on my system. This does not use the Budapest System datum... but it seems like this CS is from sometime in 1970s. Below is the content of the prj with all the patemters with this CS.


PROJCS["HD72_EOV",
GEOGCS["GCS_HD72",
DATUM["D_Hungarian_1972",
SPHEROID["GRS_1967",6378160,298.247167427]],
PRIMEM["Greenwich",0],
UNIT["Degree",0.017453292519943295]],
PROJECTION["Rectified_Skew_Orthomorphic_Center"],
PARAMETER["false_easting",650000],
PARAMETER["false_northing",200000],
PARAMETER["latitude_of_center",47.144393722222],
PARAMETER["longitude_of_center",19.048571777778],
PARAMETER["azimuth",90],
PARAMETER["scale_factor",0.99993],
PARAMETER["XY_Plane_Rotation",90],
UNIT["Meter",1]]

[mhampson4]

Hi

Thanks for your reply. This looks like the E.O.V projection, the modern co-ordinate system for hungary, its the one they use today (So Iv read). It uses the HD-72 datum and IUGG 67 ellipsoid.

There doesnt seem to be alot of information out there about the older projections.

[Melita Kennedy]

Cliff Mugnier in his Grids & Datums column for Hungary states that the origin coordinates of the previous coordinate system was kept secret for military reasons. He doesn't list any datum transformation information.

http://www.asprs.org...-99-hungary.pdf

There also a little bit of information here.


Melita

[Bogdanovits]

Hi Melita,

try this: http://sas2.elte.hu/tg/bajnok25.xls

Cheers,
Andras