Un-ordered output due to missing mirror_step variable

[ank1m]

Issue:

StitchEE uses mirror_step variable to sort granules but l2ss removes mirror_step from the output when variable subsetting is requested.

Solutions:

• Request l2ss to always include mirror_step and xtrack, similarly to longitude and latitude logic:
  • Cons: also makes this approach very TEMPO specific
• Request EDS client to revise their variable subsetting interface by removing non-optional variables from selection and pass Harmony requests always including these variables:
  • Cons: direct access to Harmony API or via harmony-py would still allow user to remove non-optional variables
• Discuss other solutions: creating additional flag for non-optional variables to be passed by Harmony to the services?

Workaround

• Use longitude, filename or time to sort granules

[chris-durbin]

There's a concept of 'coordinate' variables that the L2SS team asked for a couple years ago (HARMONY-1121). I'd check with them if they keep all of the coordinate variables in the output file when they perform variable subsetting. If so that could be another solution - define mirror_step and xtrack as coordinate variables in UMM-Var.

[danielfromearth]

We are now ordering the files by time. It's not the ideal solution, but closing this issue for now.