View Full Version : Degree/minutes to Grid Ref

10th August 2005, 12:21 PM

Now that I have settled on the Garmin Venture (hope that tax return arrives soon), not sure why I am more interested in navigation now that I am out of the regular ARMY, I guess there was always somebody either telling you where to go or you were following them and I was OK at map to ground.

One reason for justifying the purchase of a GPS was I could play with it when I am away with the ARMY Reserves.

My question are,
1. Can one convert degrees/minutes to a grip ref
2. Does the venture give me 6 or 8 figure Grid Ref
3. What is the easiest way to plot Degrees/minute onto a map with grid lines
4. When I have a grid ref can I input this into the gps as waypoint/destination

I have had a look on a topographical map we use in the ARMY and degrees/minute are marked around the edges. I am assuming that the GPS will only give me degrees/minutes so plotting the spot would be time consuming.

On my HEMA map of the Simpson which has the degrees/minutes in a grid it would be quite easy to plot my position using a couple of little rulers.

Not sure if that makes sense, I think I confused myself by the end.

10th August 2005, 01:02 PM
not 100% about the garmin because i'm a magellan man (its sort of like ford vs holden or dirtbike vs 4wd isnt it!)but every gps i've seen will let you set it up to suit the map in your hand.
lat/long (in different formats) or UTM (grid) and then you set the projection which mostly is gda94/wsg84 or on older maps aus66/agd66 or aus/agd something else.
then just buy or make yourself up some graduated rulers according to whatever system you end up using on firmish see through plastic and you are armed and dangerous.

10th August 2005, 02:20 PM
1. Can one convert degrees/minutes to a grip refYes. Set the coordinate format to the format you want to input and after entry, change the format to the one you want to read.

2. Does the venture give me 6 or 8 figure Grid RefThe grid ref format will also be determined by the coordinate format on the GPS set up. If you set it on the GPS to the standards defined on the map, they should read with the same number of didgits.

3. What is the easiest way to plot Degrees/minute onto a map with grid linesUse the GPS to convert to the grid ref coordinates, as described above.

4. When I have a grid ref can I input this into the gps as waypoint/destinationYes

Reinforcing what HelterSkelter has mentioned, You will quickly find that using the correct the datum is critical to successful GPS navigation. Always set the GPS to the datum specified on the map, before you start entering coordinates, or you'll drive yourself nuts trying to figure out why you're lost.

10th August 2005, 08:58 PM
Thanks guys for your response, very helpful, I'm sure this will all make sense when i have the gps and have a good read of the user manual and than go out and see if i can get lost!!!

11th August 2005, 06:00 AM
Good luck Kelvin,

Once you're comfortable using the gps (ie. sick to death of manually entering coordinates), talk to us about the next step. There is heaps of software that can make this exercise easier and quicker.

18th August 2005, 01:43 AM
Peoples, don't be afraid to read the manual for answers. It's not that hard really... often a quick guide is supplied and by just having a fiddle with the GPS by taking it out of the packaging and shoving 2 AA Alkaline batteries in will be fun I can assure you. You can't bugger it and by attacking the setup page first you will see what options are available to you. Keep in mind the settings are dependant on what your map's grid is. If you can't set the time zone suitable for you, you may need to set it to other and that will allow you to change it to +8 or +10 of GMT in a window next to "other".

18th August 2005, 09:27 PM

I know where you are coming from.

If you look at the OZI web site you will find a reference to the MGRS dll. MGRS stands for Military Grid Reference System. I have an old Magellan that uses MGRS as an option and I can specify 8,10,12 figure grid references. On top of that the UTM system is effectively an 8 figure grid reference. Just grab an old 1:25, work out a grid the way they taught us at Kapooka and then get the same GR from your GPS - you will know which numbers to drop.

My "old" magellan actually works in mils but the new bluetooth receiver is strictly Degrees/Mins/Secs. You could always multiply by 16.999999.


18th August 2005, 10:43 PM
Hope this doesn't turn into a this brand v's that model wrestling match, but here goes :rolleyes:
I was just playing around with my (Magellan)Meridian. On the 'Position' (Nav) screen you can toggle between two different views, and one of them is to view two different co-ordinates data sets at the same time. (just what you need??)
The datums and co-ordinates can be set in the setup menu, where you get the option to set a primary and a secondary co-ordinate and datum set. And they operate as they sound....... the primary is the main data set, and the secondary is the set you can compare to.

ie. at a glance I can see that my current position is UTM 55 3***xxE 5822***xN using WGS84 AND that translates to MGRS(1 meter) 55HCU 19aaa 22bbb using AGD66. Or use whatever combination of data sets you like!

If that's what you want, then it's very easy :D