GPS/Mapping Tool.

[Neil]

I was thinking of ordering one of these: http://maptools.com/products/PocketCorners.html
for going from GPS to map and vice versa at home and in the the field .
Looks pretty good to me but is there anything better out there?

Another question.
When using Topo! software I can choose my datum and then ensure the gps and software match when uploading. However, the USGS quads all use NAD27 for their grids, right? Say my receiver is set to NAD83 and I plot the coord. on my paper map. Obviously I'm going to be off. So shouldn't I and everybody else simply stick to NAD27 all the time? I often see WGS84.

 

[Rick]

Neil, if you have access to a laser printer, you can simply download the PDF file from their site and print out the grid on a sheet of overhead transparent plastic, tape a second piece to the back for sturdiness and cut to size.

I have made a few this way and they work great.

 

[John Graham]

I have looked around a lot and I don't think there is a better selection of grid readers and corner rulers than the ones at www.maptools.com . Also, his prices are much lower than the few others available.

As far as the map datum, not all USGS 7.5 minute maps are NAD27, all the ones made after 1983 are NAD83, which is vitually identical to WGS84.

 

[Remix]

Yah- Brunton makes a compass with the grid tool built in.

To use the grid tool effectively, you will have to tell Topo to draw gridlines on
your map-- or you can do it yourself.

Can't think of better way to pick up map and compass techniques on your own. Shoot your bearing and compare to the answer provided by the gps....

PS... check the tool to the map before you go...with all the darn settings on inkjets, printer drivers, and Topo, its easy to distort the map grid.

 

[DougPaul]

If you use such a tool on a map that you have printed yourself, check to make sure that the map is indeed the proper scale on the paper.

An easy way to do this is to match 1km on the plastic scale to the 1km scale on the map or to a UTM grid printed on the map.

BTW, WGS-84 is the native datum of the GPS system, so it tends to be the GPS default.

Doug

 

[masshysteria]

Neil, I purchased one of the grid tools a couple of years ago. At first, it was a very useful piece of equipment. I used it to find the UTM coordinates of a waypoint that I wanted to manually enter into the GPS. However, now I use the Topo programs to enter waypoints. Much quicker and easier, though I still have the grid tool with me in the field, in case I want to enter a new waypoint.
If you use the Topo programs (I use both Delorme and National Geogr.), you'll probably end up printing their maps to use in the field, instead of the bigger USGS quads. Less wear and tear on the USGS maps. All the topo programs usethe WGS84 standard, or at least the ones I've seen, so if you keep your GPS set to that standard, there shouldn't be a problem.

Tom

 

[Neil]

Reading the responses to my question got me to thinking about making up my personal orienteering clinic. ie. for me alone. I'm thinking that a savvy blending of map and compass skills with gps technology (ie. it's not an either-or type of thing. It's both!) is the way to go, especially if one has designs on the ADK hundred highest and other fun stuff. I'm sure it would be easy to come up with a bunch of ideas for imaginitive exercises. Anybody got any ideas?
Oh, and BTW, I noticed that software to printer thing, gotta make sure a klick equals 4 centimeters, eh?

 

[DougPaul]

I'm thinking that a savvy blending of map and compass skills with gps technology (ie. it's not an either-or type of thing. It's both!) is the way to go,

Yep. Each tool gives you different information and has different failure modes. Knowing how to integrate info from all or any subset is a worthwhile skill.

Oh, and BTW, I noticed that software to printer thing, gotta make sure a klick equals 4 centimeters, eh?

Only if you want your distance measurements from your plastic grid to be accurate...

Doug

 

[Mark]

UTM Grids

I tried making my own grid overlays for my AMC trail guide maps. One problem I found was that it was difficult to create a grid that I could use on all my maps since the horizontal scale (east-west) varies slightly from map to map (and even on the same map) due to the convergence of the lines of longitude towards the north pole. The variation was quite minor - perhaps a millimeter or two from the top of the map to the bottom, but it was enough to throw off measurements with the overlays. Does UTM solve the problem with converging N-S lines? I might be able to print out my Topo maps using UTM, but I'd like to get or make an overlay that I could use with my AMC maps since they have more trail detail.

 

[masshysteria]

Mark
Don't quote me on this, but as I recall, there is a UTM setting that allows for the convergance of latitude lines in the northern hemispere. On my Garmin, it's in the setup field for "position format' as UTM UPS. The only other UTM format I have is UTM user grid. I believe there was a link on the Garmin website that explained in detail the different Lat/lon settings. As far as a mapping program using this , I don't think so. The two programs I use have a UTM setting, but It doesn't clarify which one (UTM UPS or UTM user grid) it is.

Tom

 

[Neil]

I tried making my own grid overlays for my AMC trail guide maps. One problem I found was that it was difficult to create a grid that I could use on all my maps since the horizontal scale (east-west) varies slightly from map to map (and even on the same map) due to the convergence of the lines of longitude towards the north pole. The variation was quite minor - perhaps a millimeter or two from the top of the map to the bottom, but it was enough to throw off measurements with the overlays. Does UTM solve the problem with converging N-S lines? I might be able to print out my Topo maps using UTM, but I'd like to get or make an overlay that I could use with my AMC maps since they have more trail detail.

UTM virtually elimates the convergance problem with lat/long which is why I think they invented it. Don't your maps have UTM numbers? If you wanted a project to keep you busy on a rainy day you could figure out how to convert the lat/long to the UTM#'s then put them on yourself, draw the grids on the map etc. Then you could sell it!