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[closed] Ordnance Survey .qct Grids and AlpineQuest in-app Grids/GPS locations don't match.

Posted: Sun Oct 16, 2016 10:25 am
by ma3974
So, I purchased the full version of AlpineQuest to be able to use gridsquares on maps.

I have currently got UTM grids displayed over an Open Street map. It is when I displayed an Ordnance Survey .qct Memory Map of my local area the I noticed that the grid squares are way off from one another i.e. the UTM Grids that are displayed by the app and the OS Grids that are an actual part of the map which are printed in blue, do not even closely match for the same locations.

What is more is that the GPS Coordinates that are displayed match those of the UTM Grid displayed by the app and not the printed blue OS Grids.

I have also noticed that the AlpineQuest in-app UTM grids seem to be slanted to the left slightly, which means they are more than likely oriented to True North as apposed to the OS Grids which are oriented to Grid North.

Can anyone please shine some light on the issue as I am no expert.

Thank You in Advance!

Re: Ordnance Survey .qct Grids and AlpineQuest in-app Grids/GPS locations don't match.

Posted: Sun Oct 16, 2016 10:38 am
by ma3974
It would appear that after doing a bit of digging that OSGB and UTM grids are not the same and won't match up anyway.

Any further information on this topic would still be appreciated.

Re: Ordnance Survey .qct Grids and AlpineQuest in-app Grids/GPS locations don't match.

Posted: Sun Oct 16, 2016 11:43 am
by Psyberia-Support
Hi and thanks for your support.

UTM and OSGB grids are not the same at all, so it's natural that they don't match on the map.

UTM is a worldwide grid, based on the WGS84 datum, which is used by GPS.
OSGB is a grid designed for UK only, based on the OSGB 1936 datum (not the same shape of the earth).

Note that you can display the OSGB grid in AlpineQuest: in the app settings, select the location format, then click on "More..." at the bottom of the list and select "UK OSGB Grid". The grid displayed by the application will then match the one from on map.

Let me know if you have any additional question
Best regards