Bushwalk Australia

A friend has a Magellan GPS and could only get grid references as lat and long. Can someone plase advise me if it is possible to have a grid reference in the form 123456, albeit with a few more numbers at the start of each group of three?

If not, my friend intends to get a Garmin 30X. My recollection is that Magellan and Garmin maps cannot be interchanged. Is this correct? If so, is it acceptable to copy the maps on a Garmin to the new one? Or maybe there's a place that has Garmin maps for less cost than Garmin. The maps are pretty big, some 45 MB from memory. TIA.

No ideas if the Magellan can or can not provide a grid reference but I’d think it’s there, just have to go find it in the settings, like the Garmin. Otherwise the maps are not interchangeable. One good reason for going with the Garmin is its wide selection of 3rd party maps.

Yes you can.I don't remember how I changed them and assume it is in the settings but I will check on mine if he can't work it out.

Not familiar with Magellan but this model (Magellan eXplorist 310) seems to have what you need in

Settings -> Navigation ->

The manual (Page 29):
http://www.navmantech.com/aumarketing/E ... Manual.pdf

I've received advice from my friend that the Magellan cannot show conventional grid references in the form 123456 or similar, and that a Garmin 30X is wanted. The best price I can find is GPS R Us, $315
http://www.gps-are-us.com/product_info. ... ts_id=3667

Is it worth waiting for a better price? Also, what is the best place to obtain maps? TIA.

What model Magellan? That's a good price for the Garmin. Lots of maps available but give us a bit more information on how he wants to use the GPS. Some map versions are better than others for walking.

Which model Magellan? You probably can't get just a brief six digit grid ref (does any GPS do this?), but it should be possible to set it to the full-length numbers from which these are derived.
settings >navigation >UTM
Then check you have selected the appropriate datum.

That's all it takes.

For magellans, you can set grid reference as the coordinate system setting pretty much as the described in the manual for the explorist 310 that GBW posted if your mate has one of the later Magellan Units.

But even the older Magellan GPS units (before the company was acquired by MiTac) like the Sportrak and Meridians that came out around 2002/2003 can display MGRS coordinates. The instructions above are for the later Magellan units like the triton, or explorist series etc. I can't recall the steps for the earlier Magellan units, but if they have the later units that use the modified Windows CE platform, the instructions are similar to this:

Go to Tools > Settings > Navigation or Menu > View > Settings > Navigation.

Then you should see that it currently says something like:
* Coordinate System: Lat/Long
* Coordinate Type: Degree

Change the Coordinate System to: MGRS
Next there should then be an accuracy setting. This is the number of digits you require (eg. 10 m accuracy will mean an 8 digit grid coordinate, 100m accuracy will give you the 6 digit grid coordinate).
Then there is an MGRS setting (between MGRS1/MGRS2/MGRS3). From what I recall, MGRS1 was the MGRS Old as defined by the NGA, and MGRS2 was the MGRS New. I don't know what MGRS3 was. I would pick MGRS2.

Finally make sure you select the correct Map Datum on the Magellan as well.

For maps, you are correct, Garmin maps are not compatible or interchangeable with Magellan maps.

There are very good OSM maps available for each platform. For example, viewtopic.php?f=21&t=21160 has some OSM maps for the Magellan, and andrewp's compilation of the OSM maps for Garmin. viewtopic.php?f=21&t=14234&start=150

I think I installed the OSM maps on your eTrex as well.

Keithy, thanks, I'll pass your comments on. You installed maps, makes it easier to see things. I am so glad I got the 30X instead of my original choice, 20x. The map was out by 1-200 metres altitude on very steep terrain in the Blue Mountains. Strangely, the trip computer altitude was more or less correct; it's a bit hard to judge when on a near-vertical face. The last link in your post is kaput.

Lophophaps wrote:The last link in your post is kaput.

I fixed the link now, thanks.

With elevations, I'm not sure if you mean the digital map on the Etrex was reporting the incorrect elevation (contour lines) or if you mean the GPS was reporting the incorrect elevation.

Firstly, if it was the digital map, it could be errors on the map. I know the V5 Garmin Aust/NZ Topo has some discrepancies that were introduced into the maps that weren't there on previous versions. There is an earlier thread about the errors somewhere here.

If it is the GPS reporting the incorrect elevation, this is generally because while GPS is great on horizontal accuracy, vertical accuracy is less so. The elevation error can be +/- 400ft or 120m. To counter this, the Etrex 30x incorporates a built in barometer which if set correctly can make adjustments for elevation. Note that in variable weather, like a storm front, you are still better off manually calibrating the elevation as the barometer will be thrown out by the sudden drop in airpressure and might adjust it as an ascent.

To adjust barometer settings on the eTrex 30x, go to Settings > Barometer. You should see a screen like this:


There are basically three ways to set this:

• 1. Set the first option (Auto Calibration) as ON. This will mean that the GPS will use the barometric setting automatically to adjust the reported GPS elevation. As mentioned above however, this can be thrown off by sudden changes in air pressure due to changing weather systems.
• 2. Manually set the elevation using the bottom option (Calibrate Altimeter) at your starting point, or at a known elevation (using map contour line or physical elevation marker), then set the Auto Calibration to ON.
• 3. Set the Auto Calibration to OFF, and at regular intervals during your walk (half hour/hourly, etc) manually set the Calibrate Altimeter to known elevations.

I usually do Option 2, and manually calibrate when stopped for lunch or camp. Make sure you leave barometer mode in Variable Elevation. Setting it in Fixed Elevation I have found is good to record the barometric pressure trends while at campsites.

Keith, thanks. I've barely touched the deeper functions, and will study your advice tomorrow. Most of the time the altitude is accurate enough for my purpose. However, setting with option two appeals.

Off topic, it was interesting to see the GPS work flying to Sydney when I was next to a window and not at all coming back when I had an aisle seat. Faraday cage effect, perhaps - no signals.

Yes, GPS logging on flights is interesting but altitude can go haywire for those with barometric sensor.