GPS Newbie Questions

I updated the software version of my etrex to the latest available which includes a NZTM2000 setting; I set it to that but the readings it gives below the waypoint dont refer to grid coordinates or lat / long readings? Is there a way of relating gps readings to paper map or do you just use them as a duel system? Ta!

As an example, what readings does it give? Mine clearly shows grid references like E1746627, N5433303, so I can just draw read it straight onto a paper map if I need to. If you have an Garmin GPS and it *says* it supports NZTM, you should certainly be able to get grid references out of it. If it's the basic style of eTrex (or eTrex H), it won't know specifically about NZTM on its config menus, but you can set it to WGS84, put it into a custom mode and enter a few parameters to get effectively the same result. For details, visit http://www.topo50.govt.nz/faq.html and read the answer to the question titled "Can I still use my gps?"

fyi neilpendo http://www8.garmin.com/aboutGPS/manual.html

You could tell us what model of GPS you have so we can help you better. The user grid is a blank grid so I am not suprised you get USR____ You need to set the grid to "New Zealand" if you are using the older 1:50,000 maps or to "New Zealand TM" if using the newer Topo50 series of maps. If your GPS is an etrex it may not have NZTM so therefore you need to set up a User grid. The instructions to do this are on this site at http://www.tramper.co.nz/?4856

Thanks all for your advice. I am using the etrex h and downloaded the latest software update which includes NZTM as an option. I set this as the position format and the map datum to WGS 84. I reloaded my waypoints and by paying careful attention to the coordinates on the corner of my paper map ;) was able to relate the gps readings to my paper map. There are some occassional discrepancies between the hut coordinates I downloaded from Zenbu and their position on the map but this could be a mix of map error and gps error. I couldn't get it to work when entering the user grid myself as advised, even though I checked the data I entered a few times. Thanks again Neil

Sounds like you are on your way. That data from Zenbu is good, it is straight from the DOC database and has all their huts in NZ. I have found it all to be pretty much spot on.

Hi, for what its worth, before I go anywhere I scan my topo map where I am going to produce two A4s, which I put back-to-back. Then I go over the lines of longtitude and lattitude with a ruler and fine black pen to make them obvious. Then, along the bottom and side, I write the numbers in off the map, so they are also obvious (when you're exhausted) Then I get it laminated. On the ridge, I just use the coordinates out of the eTrek. I find the whole waypoints thing a waste of time, due to the nature of our bush. Pretty easy to translate those eTrek numbers on to an (orientated) map with a little practice. So you establish where you are, then you put the compass down on the map and set the dial so the pointer is set where you are going. And off you go bravely into the mist! Warning - check your GPS is set to the same system as used in the map, because the maps just changed.

Hi John. Do you mean the map grid lines are the ones you trace, or do you actually use the latitude and longitude? I'd have thought they'd be easier for accuracy than lat/long.

I'm talking about the feint black lines that form a grid pattern within the standard topographical maps (not park maps). Where each line intersects with the edge of the map there is a number. That number rises in value up the sides and from left to right at the top and bottom. I make the lines heavier because they are hard to see in low situations in the bush. Also, if you make an A4 of where you are actually going, writing in the numbers on the edge of that A4 makes everything much easier.