Epoch Date Support in ArcGIS Pro, Explorer, and Collector

[MattBrady]

Currently there is no way to see what epoch date coordinate systems are using in the core ESRI products (ArcGIS Pro, Explorer, and Collector).  Likewise, besides being able to see the default epoch date for a coordinate system, it would be nice to be able to adjust the epoch date for a coordinate system on the fly, or at least be able to specify the epoch dates to use when re-projecting data from one coordinate system to another coordinate system.

[MelitaKennedy]

Hi Matt, 

We've been debating how to implement time-based transformations which would include the ability to persist epoch (date-of-collection) information as well. The ISO metadata standard has now been updated so that information can be stored there. That still can cause some issues in the projection engine because that library sits so low in the software stack that we would have to figure out how to access the metadata files! 

We've been adding the transformations and some supporting functionality to the projection engine but we still need to get it exposed above in the software stack. 

Melita

[MelitaKennedy]

My colleague, Kevin M. Kelly, pointed out that I should clarify that epoch information is connected to the data rather than a geographic coordinate system. That was a long discussion in the ISO 19111 (coordinate reference system and transformations/operations data models) committee on the last revision. It would be easier for me if it was on the CRS, but it is really a data attribute. That complicates implementation for us a bit.