Tag:source:ele=barometric
 source:ele = barometric
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Elevation information obtained by barometric measurement with N samples. 
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| Group: annotations |
| Used on these elements |
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| Useful combination |
| Status: in use |
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Where elevations are tagged, source:ele=* can store information of the elevation measurement.
With some precautions a reasonably accurate measurement can be obtained with a barometric elevation meter - at least if the measurement is repeated on several trips. The precautions include:
- calibration of the equipment with a known elevation
- constant sea level pressure for the duration from the calibration to the measurement - few hours at most.
- constant temperature of the equipment or temperature corrected equipment
Note: one reasonably accurate measurement can still be even several meters off. Calibrating by the physical sea shore at water level might lead to a significant relative error for the first few meters upward. Experiment with your equipment first to learn when, if ever, its readings are reasonable.
Values
- barometric or barometric*1 The elevation tagged on this object was obtained with one reasonably accurate measurement
- barometric*2 The elevation of this object is the average of two reasonably accurate measurements
- ...
- barometric*n The elevation of this object is the average of N reasonably accurate measurements
If encountered on an object for which you have obtained a new barometric altitude measurement, you should calculate the new average and update the source:ele=* accordingly.