If the datums for different sources are different then the values need to be adjusted when merging the data. This column records the value added to the origin value. For all other situations the value of this field is 0.
This material is based upon work supported by the National Science Foundation under Cooperative Agreement #DEB-2025982, NTL LTER (ROR: 04gq8q482). Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.