Lost & Found

Masterfile

Hiking in the woods is great; hiking in the woods when you’re alone and not sure where you’re going is less so. Fortunately, handheld GPS (global positioning system) units and two-way radios mean it’s harder than ever to get lost during your weekend activities.    

Sales of handheld GPS units continue to set records (8.7 million units sold in 2007 with 2008 expected to top that by 3 million units, according to industry sources), and it’s easy to see why. Today, you can find handheld GPS units that have high-resolution color screens and expanded memory capacity in models in all price ranges. Before, these features were available only on higher price units.

Although sales of two-way radios have declined, manufacturers have added more features in hopes of luring customers. Significant recent additions include sought-after conversation-privacy features, hands-free operation and emergency warning systems. Radio reception has never been better, but watch out for distance claims that could lead you down the wrong path.

GPS IN A FLASH. Earlier versions of handheld GPS units relied on built-in memory that set boundaries on the amount of information these devices could hold. In 2007, SD cards, flash-memory devices about the size of a postage stamp, were introduced to handheld GPS devices. This pushed out the information boundaries. Some makers even tout their handheld capacity as “unlimited,” which means the limit is only how many SD cards you want to carry with you. Currently, the largest SD card is 10GB ($150), which is enough to hold 10 to 20 map and chart programs. That’s great if you do a lot of traveling, but for most consumers, a 1GB or 2GB card, which cost around $9 to $12 and can hold one to three maps, is plenty.

Handheld GPS makers also sell preloaded cards that contain maps, satellite imagery, nautical charts and aerial imagery that graphically depicts the woods and open areas where you are. But you need to know that many of these preloaded SD cards are designed to work solely in a manufacturer’s own product. (For example, a DeLorme SD card works only with DeLorme handheld GPS units.) So, if you update your unit, many of your SD cards could become worthless if you purchase a model from another company.

A few GPS manufacturers also offer maps and charts for download on their Web sites. The programs are downloaded directly into your handheld GPS and can be moved to an SD card, like buying a song on the Internet. Downloads are necessary for cheaper units that do not have SD card technology. These programs are the same as those found on preloaded cards. Prices, which have not changed much in the last 3 years, average about $100 per program regardless of format.

GETTING A GPS FIX. One other area where handheld GPS units have greatly improved in the last few years is in satellite reception sensitivity. There are dozens of GPS satellites orbiting the Earth around the clock in a set order, and they come and go quickly over your location. A GPS receiver needs to be able to receive only two GPS satellites to “fix” your location (identify your latitude and longitude) and three satellites to determine your location’s elevation.

Three years ago, getting a fix often required an antenna on the car roof if you were driving. If you were under a bunch of trees, reception was sloppy at best. That has changed. What’s more, “cold start” time, the elapsed time from when each unit was turned on until it could acquire enough satellite signals to get a fix on the ground position, has lessened significantly. The result is that cold start time is typically about a minute. It took 3 to 5 minutes previously to get the needed signal. Plus, now you can also get the same reading indoors as you would get outdoors, and trees have no effect on the signal, so you can find your way back to your car a lot quicker.