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# North - East

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A fairly simple question, I think, yet one for which I have been unable to find an answer:

When giving co-ordinates in Lat Long we give the Northings then the Eastings. However, when using any of the other formats UTM, British OS, MGRS etc we give the Eastings first then the Northings.

Whilst I know this to be true I don't understand the rational behind it. Surely this is confusing and unhelpful and I'm sure that there is a clear historic reason behind this.

Can someone please help me as it's driving me mad.

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With UTM coordinates you describe the location of a point (x,y) in a plane. The x-value is the easting, the y-value is the northing. Lat/Long are cartesian coordinates, that's something completely different.

Cornix

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Nevermind. I typed out an answer, but when I checked my work, I had some of my symbols mixed up, so my answer was incorrect.

I guess I don't know.

Jamie

Edited by Jamie Z
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Finally found an explanation on the web:

Geographical Coordinates (Lat & Long) were in use before Rectangular Coordinates (grid references) with regard to CHARTS and MAPS.

Centuries ago mariners found it relatively easy to establish Latitude by measuring the angle the sun was above the horizon with a crosstaff as it transited the observers meridian (north south line). As the declination (celestial latitude) of the sun could be predicted by date a simple calculation (in 2 dimensions) could produce a fairly accurate Latitude. And centuries went by without producing a reliable Longitude because the accurate time pieces needed that did exist were unsuitable for going to sea and radio waves that could send accurate time signals were in the future. It was naval tradition that put Latitude first and for hundreds of years there was only Latitude anyway.

The landlubbers were starting to refine the maps, and without a perfect horizon (the sea) that could be used as a datum to measure vertical angles from and lots of landmarks instead, magnetic compasses were used to resect the observer on the ground. Rectangular coordinates or graph coordinates use measurements along an X axis and then measurements along a Y axis in exactly that convention. This time the X measurements or eastings are so many metres to the right or east of an origin outside and to the left of the map and the northings are so many metres up or to the north of the same origin outside and to the bottom of the map. Actually this origin is the false origin that is placed there so that the eastings and northings always have a positive value.

The Navy got there first and in fine naval tradition were not about to change.  ...

Source: Birding-Aus Mail Archive

Cornix

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.... Lat/Long are cartesian coordinates, that's something completely different

Yes, Cartesian coordinates are something completely different but no way are Lat/Long the same as cartesian coordinates.

Cheers, Kerry.

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Thanks for the replies, especialy Cornix. As with everything (generally) the answer is obvious; once you know

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