Tracklog

From Geohashing
Revision as of 04:29, 29 April 2009 by imported>Robyn (GPS Visualizer: typo)

A GPS tracklog can serve as proof of reaching coordinates, or just make an interesting addition to an expedition page. If your GPS receiver has a USB port or a mini-USB port, or can interface with a device that does, you can probably record, save and upload tracklogs. If you don't know how to do that, perhaps this page can help. If you do know how, please help enhance this page for others.

Track recording

Track recording, or tracking, is a function that allows your GPS receiver not only to display where you are now, and where you're going, but to keep track of where you have been. In order to have a tracklog you need to have this function, and have it turned on. Look through your menus or manual for tracks, track recording, track plot or something similar. If your screen displays a trail showing where you have been, then you definitely have this feature. Your GPS may already have location tracking turned on by default, even if you don't see a track displayed on the device. You probably have unknowingly recorded every move you have made with the GPS turned on since you bought it! It's analogous to Hansel and Gretel in the forest, dropping breadcrumbs, except it's not affected by birds.

Settings

Obviously you want the track log turned on, and there may be other settings too. These explanations for settings you may have. The defaults are probably fine.

Wrap when full continuously erases the oldest tracks and replaces them with the newest. This setting ensures that your GPS won't stop recording because the memory became full. There's not much reason not to use it. If you want to save your oldest tracks, copy them to your computer.

Record method selects how often the GPS saves a point on your path. You may be able to tell it to drop a breadcrumb based on the passage of time, or on distance covered. In Auto mode, if available, points will be recorded just as often as is necessary to give a good representation of your motion - more points in curves and when your speed changes often, fewer while moving in a straight line at constant speed.

Interval determines the time or distance interval between breadcrumbs. If your tracklog doesn't show as many little twists and turns of your trip as you'd like to, adjust it to record more often, or to a fine track. If your memory fills up before you have a chance to download the data, adjust it to record less often or a coarse track.

Saving

Once you have moved somewhere while the GPS is turned on and track recording is turned on, you have the opportunity to Save that track. A Garmin etrex gives the choice of saving the entire track or specifying the endpoints of the saved track. The latter is quite fiddly. If you turned your GPS on at the beginning of the part you wanted to save and off at the end, it will be much easier to save the entire tracklog and then delete everything you don't want after uploading.

Once that you're sure that your GPS has recorded and saved the track, it's time to get it out of the GPS.

Transferring a tracklog

If your GPS receiver came with software, now's the time to get out the CD ROM and install it. If you didn't get one or lost it, try the manufacturer's website. You probably need to have software installed before connecting your GPS receiver to your computer.

Connecting your GPS receiver to a computer

Mini USB port on the back of an etrex

Your GPS receiver probably has a way to connect to a computer. You could have a mini-USB port hidden under a flap as pictured. If the GPS didn't come with a cable that connects to it, you may have a camera or other device that uses the same cable. They're also cheap to buy. If your GPS receiver is part of a computing device, like an iPhone then you don't need to connect it. Skip down to your software, if someone has made that section yet.

Map Source

The Garmin product is called Map Source. Once it is installed, start the program and connect your GPS. From the Transfer menu select Receive from device. It should find your GPS. Select the check boxes to receive Waypoints and Tracks (but not Maps and Routes). Then click Receive. You'll soon have the left hand pane of the program filled with log files, representing every time you've turned the GPS on and off.

First, use Ctrl-S to save the entire thing together. The default .gdb file works fine. Then save it a second time under a new name, the name of the expedition you want a tracklog of. Now delete everything that isn't the expedition you want. Each log line is tagged with the date, so it's very easy to identify what you don't want. Just highlight and delete everything with a date other than your expedition. If you're using UTC times be careful not to be confused by the UTC date starting/ending at a different time than your local date. Do the same with waypoints not relevant to your expedition. When you've trimmed everything you don't want, save it again. You should now see your route displayed on a crude map in the right-side pane. You're now ready to upload it.

Other software

If you're running some freakish unsupported operating system you probably already know where to go to look for for open source software to help you with this step, and very likely don't need a wiki help page on manipulating data.

Uploading tracks

There are multiple ways to upload your data and display it on a map to show your route. Add any you know.

Everytrail.com

http://www.everytrail.com - reads most file formats (gpx, kml, ...?), displays an interactive map and track statistics. You can add travel reports, geotagged photos and the like.

GPS Visualizer

Open the GPS Visualizer site in your web browser. Browse to your file, accept the default Google Maps format (you can change your mind later). Upload.

Hosting

The wiki does not currently accept KML files, so unless you save your map as a JPG or PNG you will need somewhere to host the file in order to link it from the wiki. Suggestions here ...

RTFM

Also check your user's manual. Many manufacturers make user manuals available on the Internet.

Difficulties or Questions?

If your GPS receiver or software isn't listed here, please ask about it on the talk page. If you know something about tracklogs that isn't listed here, please add it in.