Touring - Gps

I'm getting my mountain bike ready to do some riding along the Transandaluz route (http://www.transandalus.org/) and, because the trails aren't marked, I'm told I need to get a GPS device. I ran a search for "GPS" on this site, but got no results. I wonder what characteristics I should be looking for and which models I should be looking at. I can't afford to spend a lot. What are the differences between the cheaper and more expensive models?

Thanks.

I like the simple ones. They give you co-ordinates as to where you are, you can enter coordinates of where you want to be and then you can watch yourself proceed there. If your routing gave co-ordinates to follow, then you could use your GPS to orient yourself.

Along the way you can enter waypoints which are remembered points you traveled through. So if you got out of your car, and registered a waypoint, then went and got lost in the woods, you could return to the waypoint you logged by choosing it as a destination. If you selected many waypoints you could re-trace your steps.

Earlier on there was a lot of stuff about how many satellites the units could engage, and whether it was enough for certain accuracy levels or to plot altitude, but these days even the cheap units seem really capable.

You can get GPS with these features, and probably many others, for about 80-100 bucks.

Beyond that you can get mapping features so that rather than simply seeing your travels like blips on a radar screen, you can see them on a map. You can see geological features or streets on these maps. Sometimes due to error, you can see yourself traveling "down" these streets, but off to one side, still you can probably tell the route you are on. In the US, the maps are great, even on pretty cheap units, but in other countries it varies a lot, and I would wonder whether you could get GPS maps, if no regular maps exit, something to ask about.

One thing to keep in mind is that even when the GPS precisely locates your X.Y,Z, it isn't necessarily going to match up with those coordinates on a map. Maps are better and worse. Naval Charts, are far from perfect. Making them is extremely expensive and they don't necessarily spend money locating features of low economic or strategic importance. Often recreational users are more interested in precisely the areas that haven't been seriously surveyed. So just be careful that you don't get caught out depending on maps. In the early GPS days there were stories of boats nearly sailing into islands, when it turned out the charts had them in the wrong place.

Cool looking trip!


... I'm told I need to get a GPS device ...

I presume that means that area maps for loading onto a GPS receiver are available....

A couple of things about use of a GPS receiver (GPSr, in internet parlance ;) )

- Your GPSr unit needs to be able to "view" the sky to receive satellite info. This seems obvious; what it means in practice is that if you want it to record the route you've taken - to help you backtrack if you get lost - it needs to continually be receiving satellite signals. Thus it must be mounted on your handlebars, etc. You could simply pull it out at rest stops & let it quickly note your location, but depending on the terrain you're riding, the "as the crow flies" route the GPSr uses to direct you back to your previous waypoint when lost may lead you across rivers, canyons, etc.

- Assuming GPSr maps of the area are available: they take up a lot of unit memory. The cheap/basic units available inexpensively work perfectly nicely & accurately, but may not be able to store such map data. I'd 1) see if maps are available, 2) see how large megabyte-wise they are, 3) then look for appropriate GPSr. I use a cheap, low-memory-capacity unit (etrex legend) which works fine for me but couldn't load a large area map; I dunno offhand where to investigate map availability for your trip - maybe the FAQ link on your linked site tells ?

- There is LOTS of internet info available, & a number of newsgroups (Yahoo groups has forums on many specific GPSr models) where you can learn pros & cons of various GPSr's.

I use a Garmin 60cx. It is state of the art. Cost about 300 bucks, I think. I will say this about it. If you know how to use it, you will never get lost and there is enough space on the chip to store any route you choose in the US. Yahoo has several forums that will help you learn to use it. One other thing a Ram mount for the handlebars is a must have. The Garmin bar mount will not hold the unit on a rough ride.

Garmin has a web site. Go there and you will find several types of GPS units that are good for bikes and hiking. You can purchase the units on several online stores much cheaper then from Garmin.

Wes

For each of the routes they give you a list of data like the one that follows. How would I use this? Looks like Greek to me.

OziExplorer Track Point File Version 2.1
European 1950 (Spain and Portugal)
Altitude is in Feet
Reserved 3
0,3,65280,C:\Archivos de programa\EasyPHP1-7\,0,0,2,8421376
410
37.284094, -6.045123,1, 13.1,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.281364, -6.045883,0, 23.0,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.279424, -6.044823,0, 23.0,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.275154, -6.039173,0, 13.1,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.273044, -6.037823,0, 9.8,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.269234, -6.036873,0, 13.1,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.266074, -6.034163,0, 9.8,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.262634, -6.029913,0, 9.8,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.260584, -6.027953,0, 9.8,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.254624, -6.024443,0, 9.8,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
37.250674, -6.022883,0, 13.1,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37

Thanks to everyone for your helpful replies.

Here's a link: http://www.transandalus.org/andalucia/sevilla/TAS09.plt

Hopefully somebody that knows more about this than I do willl comment.

What you have got there is a track log created by somebody, either from a map or from actual GPS readings recorded while they were riding.

The first two columns appear to be latitude and longitude coordinates, I'm not sure about the next couple, but the last two are obviously the date and time the file was created.

If you input this file into your GPS, then you can follow the points along your route, rather like following a trail of breadcrumbs left by a previous traveller. The points will appear as trail of little dots on your GPS receiver and your receiver will give you the distance and bearing to the next point.

If you have this kind of information then you don't need the kind of GPS that can store and display maps. You just need the basic type that can store and recall tracks and waypoints.

Oziexplorer is GPS software that allows you to create tracks from digital maps and transfer them to your GPS or vice versa, take track points recorded on the GPS and transfer them to a digital map. I would presume that the andaluz site allows you to download these files to your computer and thus to your GPS.

I have never used this stype of software, nor transferred tracks from my computer to the GPs, so I hope somebody with more knowledge can give you more info.

I have a Etrex by Garmin.http://www.bikesomewhere.com/bikesomewhere.cfm/productLarge/261/1822/5406

I'm sure you can get one for less on ebay. It's really a cool little gadget. I use it for when I go hiking. You can download maps from your computer onto it and also make routes on your computer and then transfer them to the gps. It uses three batteries and it doesn't weigh much. Oh yeah, it has a "find" feature (like most Gps') that allows you to search for anything. For example, on my last hiking trip to Garmisch I wanted a beer so I searched for the nearest bar and hiked down to one that was on a small hill. It's not capable of giving you directions but it shows you a line connecting you to where you want to go. I hope that makes sense. I just got into riding so I have not tried it on my bike. Garmin sells a bicycle mount for it but I'm going to give this a try. http://www.instructables.com/id/ECSVP13POQEPORT6S5/

If you happen to have a new, large screen cell phone, GPS applications are becoming increasingly available for those. You might check that first.

I like the units with mapping features. It helps a lot to see the topographic data on the screen, even though the screen is small. Regarding "sky view", my device (a Magellan Meridian Color) works perfectly well inside a backpack, pannier or handlebar bag. No need to keep it visible if it's only used for logging / backup.

And you need to make sure you have a plan B in case the GPS device fails. GPS units are battery hogs, especially if they have the electrical compass feature. It's easy to run out of juice. Another thing, if your GPS dies in the middle of nowhere, you typically won't be able to fix it yourself or on the road. So you need to have a backup. Get a map of the area, and if you're in the woods, bring a non-electrical compass as well.

--J

Thanks for the links. I'll definitely be looking at making my own mount. It seems the ones Garmin sells are prone to break.

For each of the routes they give you a list of data like the one that follows. How would I use this? Looks like Greek to me.

OziExplorer Track Point File Version 2.1
European 1950 (Spain and Portugal)
Altitude is in Feet
Reserved 3
0,3,65280,C:\Archivos de programa\EasyPHP1-7\,0,0,2,8421376
410
37.284094, -6.045123,1, 13.1,chrome://fon/skin/flags/ba.gif38734.9289005, 17-ene-06, 22:17:37
- skip -


Being curious, have had a look on the track. I used Google Local, the link is here (http://maps.google.com/?ie=UTF8&om=1&t=h&ll=37.256566,-6.042824&spn=0.064353,0.1157&z=13), then made an OziExplorer map file using the program MapBuilder (http://mapbuilder.by.ru) and finally put the track on the calibrated image using OziExplorer.
One can see that the footpath coincides with the track.