When would it be necessary to perform a datum transformation?

Performing a datum transformation is necessary when mapping data from two different datums because each datum defines a specific mathematical model of the earth, typically using different measurements and reference points. When geographic information is captured from different sources using different datums—like WGS84 or NAD83—coordinates can be misaligned if the transformation is not applied. Transforming the datum ensures that the data aligns properly on a common reference frame, which is critical for accurate spatial analysis, mapping, and integration of datasets. This transformation involves mathematical adjustments to convert the coordinates from one datum to another, ensuring spatial accuracy and consistency across all data utilized in a project.

In contrast, working within a single datum does not require transformation since there are no differing reference frames to reconcile. Similarly, creating a visual representation or obtaining accurate elevation data may not necessitate datum transformation if the data being used is already in a common datum throughout the process or does not involve multiple datums.