A1.) When I display elevation on the CO what am I seeing? GPS elevation, Altimeter elevation or DEM elevation?
With two exceptions 1) the Satellite page which shows GPS elevation and 2) selecting a point on the map page which shows DEM elevation all of the Elevation data fields are based on the altimeter elevation. If you have "Auto Calibration" turned on for the altimeter then this will be close to the GPS elevation.
A2.) When I look at tracklog elevation data what am I seeing? GPS elevation or Altimeter elevation?
It depends on the Barometer Mode setting (Shortcuts->Setup->Altimeter->Barometer Mode). If you have this set to "Variable Elevation" then the tracklog contains Altimeter elevation. If you have this set to "Fixed Elevation" then the tracklog contains GPS elevation. This is the same as on the 60csx.
A3.) Will the barometer on the Colorado collect data when it is turned off?
Yes. The Colorado collects barometric data every 15 minutes when turned off. You can enable this feature by setting Shortcuts->Setup->Altimeter->Pressure Trending->Save Always.
Note: There have been reports of issues with this feature, see the Issues List for more details. It seems that the Colorado must record a tracklog point in order to display the Elevation data, that means that the Colorado must have GPS lock in order to display elevation data. Leaving the GPS in a location with a clear view of the sky might help improve this.
A4.) Can I clear the elevation plot?
Yes, but in order to clear the elevation plot you'll need to clear the tracklog. Reseting elevation data just resets the max elevation, total ascent, and other data fields associated with the altimeter.
A5.) How does altimeter auto calibration work? How long does auto calibration take?
Based on experimentation it appears that over a relatively long time period the altimeter will adjust to approach GPS elevation. In one experiment the altimeter was calibrated incorrectly to 1000' and actual (GPS) elevation was 300'. In about 90 minutes the altimeter elevation reached GPS elevation. This slow rate of change is to dampen out short term fluctuations in GPS elevation which can vary significantly (i.e. 2 x EPE) over short periods of time depending on signal conditions.
A6.) Why am I not seeing any data in the Elevation Plot Tool?
The Track Log must be enabled for the Elevation Plot to work. Check to see if you have the Track Log enabled under Setup->Tracks->Track Log->On.