Modern GPS units have come a long way. They are more reliable and more accurate than ever. Newer “high sensitivity” receivers can often achieve a lock in a matter of seconds and hold that lock through deep canyons and dense canopy.
Even the most basic units are tremendous navigational tools but most GPS users barely use a fraction of the functionality that is available to them. Here are some more advanced skills and functions that you can utilize to get more out of your GPS.
Learn to Coordinate Your GPS with a Paper Map
You know how to use a map and compass (I hope) and you would never dream of heading on an outdoor adventure without a map and compass to back up your GPS (I hope). But, do you know how to make the GPS work in concert with your map? Few GPS users do. The ability to plot coordinates from your GPS onto a map or transfer map coordinates to your GPS is an extremely useful skill.
Learn to read and plot coordinate systems like Latitude/Longitude and UTM. I prefer to work with UTM when possible but not all maps are marked with UTM grids so it really pays to be familiar with a few coordinate systems. There are a number of excellent tutorials on the web about how to do this so I won’t go into too much detail here.
You will also need some inexpensive and easy to carry tools to make your GPS and paper map get along. You will need a map ruler for the Lat/Long system and there are a variety of different UTM tools available. I like to use a UTM “corner” as an all-around tool but grid and slot tools both have their place. MapTools.com has all the tools you could ever need, great service, and great tutorials all in one place.
Many GPS units have the ability to display maps beyond just the built in base map, but this functionality is often disregarded due to the additional cost of the map files. GPSFileDepot.com has an extensive library of free maps for Garmin GPS units. Adding maps to your GPS doesn’t have to be expensive.
Being able to see your location displayed on a topographic map on your GPS’s screen can greatly aid your ability to terrain associate and navigate. It can also make transferring waypoints visually between the GPS and a paper map much easier. However, it should be noted that these electronic maps are not a replacement for paper maps. Paper maps never have depleted batteries. I also find that maps are easier to use for planning routes than the tiny screen of most GPS units.
Project a Waypoint
Projecting a waypoint is a useful skill that many people don’t even realize they can do with a GPS. If you have used your map to determine that your next waypoint is 3000 meters away at 140 degrees, you can project a waypoint to that location and then use your GPS to navigate to it without having to worry about pace count or staying on an azimuth.
With most GPS units, you simply create a waypoint, enter the options menu for that waypoint, and choose “project.” You can now input the distance and azimuth from your map work and your waypoint will be projected to your destination.
Rebuild the Satellite Almanac
This is key! Before you head out on a trip with your GPS, turn it on and place it somewhere with a completely clear view of the sky for 30 minutes to rebuild its almanac. This will allow your GPS unit to update its satellite location data which will result in better accuracy and faster, more reliable satellite locks. If you are traveling far from home, it can be wise to do this once you have arrived at the location where you will be using the GPS. Rebuilding the almanac is especially important if you haven’t used your GPS unit recently.
If you notice that you GPS is wandering while you are standing still, that your accuracy is degrading, or that you are getting strange readings, rebuilding the almanac will often fix it. In fact, this is one of the first things that customer service is going to tell you to do if you call them.
Calibrate the Compass
If your GPS unit has an electronic compass you should either learn to calibrate it and do it frequently or turn the function off. Some electronic compasses will start to show variations as the battery life drains. If I am using a GPS with electronic compass all day, I like to calibrate the compass with fresh batteries and then calibrate it again at about half charge. It is never a bad idea to recalibrate your compass.
If you don’t really use the compass features (many people don’t need it as much as they think that they do) then turn off the compass function. Turning off the compass function can add an hour or two to your battery life.
Get Your GPS and Home Computer Connected
Most GPS manufacturers bundle computer software with their GPS units. This software can be tremendously valuable to planning routes, organizing waypoints, printing maps, backing up data and all sorts of other useful functions. It is far easier to enter a waypoint on your computer than it is in on your GPS. In some cases there are even free programs out there that are even better than what your GPS comes bundled with.
Your GPS also likely comes with software to update the firmware of your GPS unit. Familiarize yourself with this because manufacturers frequently improve the performance and features of their products through these firmware upgrades.
All of these functions go beyond your typical mark-the-location-of-your-car-so-you-can-get-back-to-it GPS use. They require some forethought, some time spent in the user manual, and practice! Gather up your maps, compass, and GPS and head to your favorite orienteering course or other outdoor space. You will have a ton of fun and learn some valuable skills.
Great explanation for tracking.