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Gamma Missing from Timbalai CRS

#1

When I use the GetEpsgParametersString for Timbalia EPSG 29873, it is missing the +gamma value which results in rotated objects. Here’s what it shows now.

“+proj=omerc +lat_0=4 +lonc=115 +alpha=53.31582047222222 +k=0.99984 +x_0=590476.87 +y_0=442857.65 +ellps=evrstSS +units=m +no_defs”

It needs to have the following included:

+gamma=53.13010236111111

Thanks,
Damian

#2

Damian,
Our projection string is consistent with this official one https://spatialreference.org/ref/epsg/29873/proj4/

Could you tell me where you get “+gamma=53.13010236111111”. We can dig in a bit more.

Thanks

Frank

#3

Hi Frank,

I think your reference may be out of date.

https://spatialreference.org/ref/epsg/29873/

shows last revision in 2006 whereas

shows an update from 2014.

I honestly don’t know the history on this one. Let me know what you find out.

Regards,
Damian

#4

Thanks Damian,
Yes. You are right. The Epsg library looks out of date. I also checked the mapsuite V12 unmanage projection library. It come with the correct string with “+gamma=53.13010236111111”. We will try to update the Epsg Libary in the mapsuite V10. Right now as work around. You could use the latest string directly instead of us the Epsg number.

+proj=omerc +lat_0=4 +lonc=115 +alpha=53.31582047222222 +k=0.99984 +x_0=590476.87 +y_0=442857.65 +gamma=53.13010236111111 +ellps=evrstSS +towgs84=-679,669,-48,0,0,0,0 +units=m +no_defs

Thanks

Frank