What does the compass and barometer on the Platinum do?
There are other units with integrated compass/barometer options. These units, like the Garmin eTrex Vista, eTrex Summit, and Map 76S, will simply be referred to as the “other” units. The operation of the Platinum will be compared against those other units. The barometric pressure sensor is currently used as a weather forecasting tool. While the unit is powered on, it will use the GPS altitude to correct the current pressure to obtain a “sea level pressure.” The unit can display a plot of the pressure over the past 24 hours, which can be used to predict good or bad weather. Other GPS units can use the barometer to estimate the altitude in the event of insufficient GPS reception. This is NOT currently an option with the Platinum, although it is reasonable to expect this may be added with a future firmware. The thermometer, other than being used for internal temperature compensation of some components, is simply used as a weather-watching feature. It is not possible to get a plot of previ
