How to find Latitude Longitude Co-ordinates from a Topographic Map

Any mathematician, engineer or architect will tell you that numbers are beautiful.

There’s something pure, absolute and precise about them. There’s also something staggering about the infinite way they just exist.

Numbers help us define things and in a world where things seem out of control and in chaos, numbers bring order and structure. They help us make sense of the world around us.

And so it is with the dark arts of navigation. Numbers allow us to define absolute points on the earth and then tell us where to go to get to another point.

Angelina's Famous Co-ordinates

Angelina’s Famous Co-ordinates

Angelina Jolie has made some of these numbers famous by having them tattooed on her arm. Numbers that define a location that is significant to her, the birth place of her children.

As a hiker, this form of numbers, being latitude longitude, has never held any interest for me, as this isn’t the format of numbers favoured for wilderness map reading. Rather, I was taught to read maps by UTM or Universe Trans-Mercator or gridlines, which appear on topographic maps.

Let’s face it, it took me long enough to master navigation by this method and understanding those numbers, that when someone asked me for a lat/long for somewhere, I was a little lost. Oh and speaking of lost, it’s in emergency situations that lat/longs are most needed as this is what aircraft can use to find you.

Of course, so many folk these days carry a GPS or device that can pop this information up for you, but as with all technology, it’s important to know how to calculate this info manually from a paper map in the case of tech failing you.

So for years, I went blindly along, comfortable in the the knowledge of my topo maps and understanding grid references like 5543 2335 (Jenolan 1:25,000 xxxx) yet also seeing markings on these maps that seemed to indicate lat/long, but not knowing how to interpret them.

And so it was that the lat long light got switched on during a training weekend with Blue Mountains Police Rescue a couple of years ago. Thanks to Steve D for the instruction!

The key was hidden in the bordering frame of the map where it changes from black to white to black.

Check out the video for how to find latitude longitude on a topographic map.

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Comments

  1. skibug says

    Wow, Caro, you’ve done it again! I, too, have always used UTM for my own purposes – in fact GPS phone apps which only showed long-lat were always of no use to me – so, although although aware that there were some long-lat markings on topo maps, I only ever gave them scant attention. This piece of information is fantastic. I must add, though, that any emergency service, such as 000 or see, would accept utm if that’s all you could give them, and do their own conversion if needed – or am I being naive? Anyway, thanks again, see you on the track.

    Skibug

  2. Graeme says

    Useful video. I suspect a majority of walkers would have never given toppo map latitude and longtitude figures more than a passing thought.

    Coincidentally, it was only upon reading a trip report last week of a recent helicopter assisted walk that I discovered that’s what the air rescue people use. Still learning!

    I actually came within a whisker of being on that walk, but that’s another story. Still lucky!

  3. Mike Richter says

    There are 3 ways of writing Latitude / Longitude.

    DMS – Degrees Minutes Seconds – this is only used by Mariners.

    DM.M – Degrees Minutes DecimalMinutes – this used by Aviators, including helicopters.

    D.D – Degrees DecimalDegrees – used for computer entry.

    Make sure you know which format of LatLong you have and don’t report it incorrectly.

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