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gbif / doc-georeferencing-best-practices

This publication provides guidelines to the best practice for georeferencing. Though it is targeted specifically at biological occurrence data, the concepts and methods presented here can be applied in other disciplines where spatial interpretation of location is of interest.
https://doi.org/10.15468/doc-gg7h-s853
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Doubt about the threatment of elevation uncertainty #32

Closed RicardoOrtizG closed 3 years ago

RicardoOrtizG commented 3 years ago

I'm glad to see all of these considerations for the elevation accuracy, but I'm not sure how to document these uncertainties if I want to recover the elevation based on the georeference coordinates or just adjust them based on the best practices recommendations. For example: Having a range of elevation of 3200-3400 meters in a dataset with an unknown elevation source (like most of the time), I could use the consideration of uncertainties for unknown elevations mentioned in 2.7.2. if I'm trying to catch the coordinate between two contours in a elevation digital map. Then If I want to adjust the elevation, ¿Do I have to change the elevation based on the radius of the whole calculated uncertainty or just taking in count half of the contour interval for elevation uncertainty?. of course saving the original elevation in verbatimElevations.

tucotuco commented 3 years ago

I hope I understand you correctly. Does the section on "Contour lines" under "2.1.3.3. Feature – Path" in the Quick Reference Guide (https://docs.gbif-uat.org/georeferencing-quick-reference-guide/1.0/en/#offset-along-a-narrow-path) provide the solution to your question?

ArthurChapman commented 3 years ago

It is best - in verbatimElevation - to record the range as we don't (currently) have an uncertainty field associated with Elevation. So, to accurately record the elevation, one should record the elevation range within the Uncertainty radius. Elevation can, of course, often help refine the coordinates if one can be certain of trhe accuracy of that elevation. This can be particularly important in areas of steep gradients.

ArthurChapman commented 3 years ago

Nothing needs to be added to the document for this issue