(11/21/22) Vertical Datums and the Importance of Correct Coordinate Labeling

 This week's goal was to solve and understand why mislabeling coordinate points can drastically alter data and make it unusable. Given coordinates, the class attempted to solve why they were incorrect. It turns out some corrections needed to be made. X and Y values needed to be swapped as the projected location was in Antarctica instead of North America. Furthermore, an additional 30 some meters needed to be added to Z values to correct for the geoid shape of the Earth, something that also would have skewed data to be impossible to use.


GCPs with individual x,y,z values. 

Unfortunately data was incorrect and improperly labeled and corrected for a geoid vs ellipical model of the Earth as it relates to actual land elevation. A common mistake made by surveyors and scientists alike.

Below imaged is a cartographically correct map of the place of interest. Marked additionally are correct GCP x,y,z coordinates, along with a legend, north arrow, title, source, scale, and map author.



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