TransDEM Forum

Does anybody know what the best way to convert the Longitude/Latitude or even OS Grid references to the Northings and Eastings in Metres required by Transdem?

The coordinates in question are 54°11'44.78"N 4°23'15.69"W which is Clay Head, Isle of Man, UK

Thanks

Where exactly do you need explicit conversion, could you explain a bit what you are trying to achieve?

For geo-referencing, the dialogues in TransDEM will accept long/lat in addition to easting/northing. TransDEM will analyse the values entered and deduce the format. However, when using lat/long for maps which carry the O/S grid, mark the checkbox "lat/long is seconday grid".

So, if I was to type 54°11'44.78"N 4°23'15.69"W into the box and click secondary grid, Transdem will accept that?

I will try it out

EDIT: It does work (now, why didn't I think to do that, I really should read everything in the dialogue!)

Also important: Latitude and longitude depend on the geodetic datum. If you have an O/S map, the datum is probably OSGB36, so set this as the coordinate system. If your coordinates originate from a different source, like Google Earth, the datum will be WGS84. The difference between the two may be about 200 meters.

Here are Grid Reference Utilities.

Another...

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you can try:
http://earth-info.nga.mil/GandG/geotrans/index.html