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GPS System And Then Some
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Written by Brian J. Sero   
Monday, 09 March 2009
Two GPS units that can point north

Used to be, if you stood still in the woods and asked your GPS which way was north, you wouldn't get an answer. For that, you needed a good old-fashioned compass. But not any more. Two new GPS receivers have digital compasses: the Garmin eTrex Summit and the Brunton Multi-Navigator. Both models also include a built-in altimeter that provides an accurate reading of elevation and barometric pressure (information you can use to predict weather changes). The compass function on these units adjusts automatically for local declination. If you stray far off-course, to go around a ravine, for example, the GPS function will keep you headed toward your destination. Both units also allow you to sight a bearing to a distant landmark with the compass and then to lock in that course on the GPS function.

The altimeter must be calibrated regularly, either with the known elevation or the current barometric pressure. Once calibrated, the altimeters on both units we tested were accurate to within a few feet (even when the GPS elevation from satellite data was off by 200 feet).

GARMIN ETREX SUMMIT
Identical in size to the $120 eTrex model introduced last year, the $250 eTrex Summit adds the compass and altimeter functions without complicating this unit's friendly operating system. The palm-size Summit weighs just 5.6 ounces. The compass rose is always displayed on the navigation screen unless you choose to move to a waypoint aided only by the GPS function.

You can toggle through a variety of information displayed on the lower section of the navigation screen, including your average speed and elevation. The Summit also has sighting marks on the case that make it easy to take a bearing on a distant object.

BRUNTON MULTI-NAVIGATOR
The $399 Multi-Navigator looks like a serious scientific instrument. It's about twice the size and weight of the eTrex Summit, and the displays are unadorned with clever graphics. There are five displays, each of which reports specific information: time and date; barometric pressure and trend; altitude and rate of ascent or descent; and position in longitude and latitude.

You can select the compass display by pushing a button and navigate to a waypoint using data from the GPS and compass. You don't even have to turn the GPS receiver on to use the compass--simply hold down the compass button and that display appears.

I also like the "StraightHome" function, which lets you store a "home" waypoint by pushing a button. However, the Multi-Navigator's size, weight and price are a generation behind other units.

Last Updated ( Monday, 09 March 2009 )