Altimeter

FAQ
A1.) Where do I reset the Altimeter data (ie. Max Elevation, Total Ascent, etc) on the Garmin Oregon?
A2.) When I display elevation on the Garmin Oregon what am I seeing? GPS elevation, Altimeter elevation or DEM elevation?
A3.) When I look at tracklog elevation data what am I seeing, GPS elevation or Altimeter elevation?
A4.) Will the barometer on the Oregon collect data when it is turned off?
A5.) Can I clear the elevation plot? How?
A6.) How does altimeter auto calibration work? How long does auto calibration take?
A7.) Why am I not seeing any data in the elevation plot?
A8.) How do I adjust the X and Y axis of the elevation/barometer plot?
A9.) How do I change the type of plot that I see?
A10.) What is barometric pressure vs. ambient pressure?
A11.) How do I calibrate the altimeter and barometer?
A12.) What data fields can I display on the Elevation Profile page, and what do they mean?
Issues

FAQ

A1.) Where do I reset the Altimeter data (ie. Max Elevation, Total Ascent, etc) on the Garmin Oregon?


Setup>Reset>Reset Trip Data.

A2.) When I display elevation on the Garmin Oregon 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 related data fields are based on the altimeter elevation. If you have "Auto Calibration" turned on for the altimeter then the altimeter will tend to track GPS elevation over time.

A3.) When I look at tracklog elevation data what am I seeing, GPS elevation or Altimeter elevation?


It depends on the Barometer Mode setting (Main Menu>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 and Colorado.

A4.) Will the barometer on the Oregon collect data when it is turned off?


Yes. The Oregon collects barometric data every 15 minutes when turned off. You can enable this feature by setting Main Menu>Setup>Altimeter>Pressure Trending>Save Always. If you want to see a barometric pressure trend (the most common reason to use this function) you will also need to set Main Menu>Setup>Altimeter>Barometer Mode>Fixed Elevation and Main Menu>Setup>Altimeter>Plot Type>Barometric Pressure (or Ambient Pressure).

Tip: Most users enable this function to record pressure trending overnight as an early indicator of possible weather change. Create a profile with the settings above and call the profile "Barometer". Before you go to sleep set the "Barometer" profile. Then check the plot in the morning and switch back to your normal profile.

A5.) Can I clear the elevation plot? How?


Yes, but in order to clear the elevation plot you'll need to clear the tracklog. Reseting trip data resets the max elevation, total ascent, and other data fields associated with the altimeter.

A6.) 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.

Verify: Data above is based on the Colorado, verify for Oregon.

A7.) Why am I not seeing any data in the elevation plot?


The tracklog must be enabled for the elevation plot to work. Check to see if you have the tracklog enabled under Setup>Tracks>Track Log>Record, Do Not Show or Record, Show On Map.

A8.) How do I adjust the X and Y axis of the elevation/barometer plot?


Tap on the X or Y axis scale and you should see a message at the top of the screen that says "Adjust X/Y Axis" and "+" and "-" buttons should appear to the right. Adjust and then hit return to exit this mode.

A9.) How do I change the type of plot that I see?


You can set the plot type from Main Menu>Setup>Altimeter>Plot Type. You can select from:
There is no option to change this directly from the Altimeter page.

A10.) What is barometric pressure vs. ambient pressure?


Ambient pressure is the unconditioned pressure reading from the sensor on the GPS, barometric pressure takes into account the elevation of the unit and normalizes it to sea level.

A11.) How do I calibrate the altimeter and barometer?


The barometer is calibrated from Main Menu>Setup>Altimeter>Press To Begin Altimeter Calibration. You will need to supply either your current elevation or the barometric pressure to calibrate.

There is no option to change this directly from the Altimeter page.

A12.) What data fields can I display on the Elevation Profile page, and what do they mean?


You can choose from among the following data fields to display on the Elevation Profile page. To change a data field, touch the field you want to change, and you will be presented with a list of available data fields. Touch a data field in the list to display it on the page.
Field
 		Description
Ambient Pressure
 		Uncalibrated current pressure
Ascent - Average
 		Average rate of ascent
Ascent - Maximum
 		Maximum rate of ascent
Ascent - Total
 		Total distance ascended
Barometer
 		Calibrated current pressure
Descent - Average
 		Average rate of descent
Descent - Maximum
 		Maximum rate of descent
Descent - Total
 		Total distance descended
Elevation
 		Current altitude above sea level
Elevation - Maximum
 		Highest altitude above sea level since last reset
Elevation - Minimum
 		Lowest altitude above sea level since last reset
Glide Ratio
 		Ratio of horizontal distance traveled to vertical distance
Glide Ratio to Dest
 		Glide ratio required to descend from your current position and elevation to your destination's elevation
Vertical Speed
 		Current rate of ascent or descent
Vertical Speed to Dest
 		Rate of ascent or descent to your destination


Issues

 

Bugs

  1. Immediately after power on for a period of about 15 minutes the graph displays for ambient pressure, barometric pressure and elevation over time are broken. Set the Oregon so that Pressure Trending is set to Save When Power On and turn off the Oregon for 10-12 hours. Turn on the Oregon, set Plot Type to Ambient Pressure or Barometric Pressure and go to the Elevation Plot tool. On the pressure plot, zoom in on the X-axis to 45 min (max zoom level) and observe that the pressure plot has a huge drop to zero right around the time the unit was powered on. Zooming out to the 3hr level causes this drop to disappear. After enough new data is gathered (15 minutes) this issue seems to go away at the 45 minute zoom level. A similar problem exists with the elevation over time plot, no data is visible on this plot until about 15 minutes after the unit is powered up.(2.6)

Missing features

  1. From the elevation profile there is no way to select a location and view the map at that same location (60csx) (2.97)
  2. There is no way to independently reset the Max Elevation field from the Trip Odometer (CO, 60csx) (2.97)
  3. There is no way to independently reset the Altimeter's elevation data from Trip Odometer data (CO, 60csx) (2.97)

New feature requests

Resolved

  1. (2.5) Fixed issue with elevation over time plot.
  2. (2.5) Fixed issue with barometric pressure. The barometer data field and the barometric pressure / time plot do not work. The data field doesn't provide any reading and the plot drops to zero once 2.4 is installed. Calibrating the altimeter causes the barometer to start working again, however when the unit is power cycled the barometer no longer works. Having auto-calibration turned on with a GPS elevation does not seem to fix the issue either. (2.4)
  3. (2.4) Fixed issues with power off pressure trending.
  4. (2.4) Improved accuracy of altimeter for large altitude changes.
  5. (2.3) Added the ability to control the scale of the x and y axes of elevation plot . Tap the x-axis legend to zoom the x-axis. Tap the y-axis legend to zoom the y-axis. Elevation plot does not provide control over the scale of the "Y"-axis (e.g. elevation, pressure). If there are anomalies (e.g. spikes) in the data this can cause the plot to be zoomed out too far to see the data. (2.2)
  6. (2.3) Added elevation plot type to user profiles. Setup>Altimeter>Plot Type is not saved with each profile, it is currently a global setting and should be changed when the profile is changes like all other settings (2.2)