Irish Grid to WGS84 problems about phpcoord HOT 6 CLOSED

Thanks for reporting this @mrjose

from phpcoord.

Further to this, the MyGeodata Cloud website is generating better results: https://mygeodata.cloud/cs2cs/

This is a conversion from TM75 Irish Grid to WGS84. The output in this case:

lat: 53.2707817373
lng: -6.16661198943

from phpcoord.

Interesting...

The main reason for the discrepency appears to be the values converting Irish Grid to WGS84 I took from an OSI document here: https://www.osi.ie/wp-content/uploads/2015/07/Survey-Ireland-1999-Making-Maps-Compatible-with-GPS.pdf?ext=.pdf

If you look at slide 28, the 3 rotation parameters are expressed as positive numbers (they even include the +).

If you look at the params from MyGeoData, they are negative versions of the same numbers. When I flip the signs on MyGeoData and also adjust the other params to be the 3dp rather than 1dp versions, the numbers are basically the same.

from phpcoord.

So question is which way around are the rotations supposed to be - does the official document I've used as source have a mistake?

from phpcoord.

Fix coming up shortly

from phpcoord.

Thanks @dvdoug the update appears to have worked a treat!

from phpcoord.