Sensors

Close window to return to Shopping

Sensors include both an Electronic Compass and a Barometric Altimeter with Elevation Computer and Graphic Profiles.

Electronic Compass

Compass Page
eTrex Vista C display

Most GPS units will provide a GPS computed compass heading if you are moving fast enough. But they will not provide an accurate compass heading if standing still or moving too slowly. You need to be moving forward at least 2 MPH in order to get an accurate GPS compass heading. An Electronic Compass allows the user to view their heading while standing still or moving too slowly for the GPS to detect.

Barometric Altimeter with Elevation Computer and Graphic Profiles

Most GPS units will provide a GPS computed current altitude on the GPS Satellite tracking page. However, the barometric altimeter allows the user to track recent changes in air pressure. This in turn allows the unit to calculate a precise altitude reading when properly calibrated. The barometric altimeter will accurately report elevations ranging from -2000 to 30,000 feet. The barometric altimeter's elevation computer provides current elevation, current rate of ascent/descent, minimum and maximum elevation, total ascent and descent, average and maximum ascent and descent rate. Graphic display options for the barometric altimeter include a profile of elevation changes over distance or time, or a profile of air pressure changes over time.

GPSMAP 60CS displays

Forecasting Weather Trends and Fishing Opportunities using Air Pressure

Newer units can adjust air pressure for altitude by using GPS computed elevation and display graphic barometric (adjusted to sea-level) pressure profiles over time. Plotting the barometric profile over time can be used for general weather forecasting. A falling barometer generally means clouding weather, while a rising barometer usually means clearing weather. These trends can also be used to identify fishing opportunities.
The Geko, eTrex Summit, and original gray scale eTrex Vista will display only an ambient pressure profile. Because a change in ambient pressure will reflect changes in both weather and altitude, an ambient pressure plot over time is not a good indicator of changing weather unless your elevation has remained constant over the plotted period of time.

Close window to return to Shopping