[Proj] ACT Standard Grid (AGD66)

[Andre Joost]

Am 13.04.2015 um 17:31 schrieb Michel.Dastous at bentley.com:

>
> PROJCS["ACT Standard Grid (AGD66)", GEOGCS [ "Australian Geodetic
> 1966 ACT", DATUM ["AGD 66 ACT", SPHEROID ["Australian", 6378160,
> 298.25],-129.19,-41.21,130.73,-.25,-.37,-.33,-2.96], PRIMEM [
> "Greenwich", 0.000000 ], UNIT ["Decimal Degree",
> 0.01745329251994330]], PROJECTION ["Transverse Mercator"], PARAMETER
> ["Scale_Factor", 1.000086], PARAMETER ["Central_Meridian",
> 149.0092948333], PARAMETER ["False_Easting", 200000.000000],
> PARAMETER ["False_Northing", 4510193.4939], UNIT ["Meter",
> 1.000000000000]]
>
> The best we have is: +proj=tmerc +lon_0=149.0092948333 +k=1.000086
> +x_0=200000 +y_0=4510193.4939 +ellps=aust_SA
> +towgs84=-129.19,-41.21,130.73,-.25,-.37,-.33,-2.96 +units=m +no_defs
> <>
>
> Unfortunately this produce a displacement of around 200 meters when
> reprojected to Bing coordinate system.

What projection string do you use for the "Bing coordinate system"?

If that has no +towgs84, then no datum shift will be applied. From the 
EPSG database, I have these datum shift parameters in proj.4 notation:

tfm1108: +towgs84=-133,-48,148,0,0,0,0 
replaced by 6905 on 19.11.2014

tfm1665: +towgs84=-129.193,-41.212,130.73,0.246,0,374,0.329,-2.955 
Capital Territory

tfm1666: +towgs84=-119.353,-48.301,139.484,0.415,0.26,0.437,-0.613 
NSW,Victoria

tfm1667: +towgs84=-120.271,-64.543,161.632,0.217,0.067,0.129,2.499 Tasmania

tfm1668: +towgs84=-124.133,-42.003,137.4,-0.008,0.557,0.178,-1,854 
Northern Territory

tfm5841: +towgs84=-124,-60,154,0,0,0,0                             Papua 
New Guinea

tfm15788: +towgs84=-127.8,-52.3,152.9,0,0,0,0
tfm15980: +towgs84=-117.808,-51.536,137.784,0.303,0.446,0.234,-0.29

tfm6905: +towgs84=-128,-52,153,0,0,0,0 
replaces 1108 from 19.11.2014


HTH,
André Joost