Determine best way to implement fine output bin DRM

[grazwegian]

Testing has shown that using a response matrix with fine output energy bins reduces systematic uncertainty and matches more closely with expected results. However to use this in OSPEX requires changes to the inner workings at the stage where the response matrix is applied and so is not something that can be changed by the STIX Team.

Options to resolve this include:

Create a forked version of the OSPEX code that would be part of the STIX GSW and call that instead of the standard OSPEX

Arrange for changes to the upstream version of OSPEX - additional checks so that the new code would only be run for STIX data could be implemented.

[samaloney]

Specifically this refers to a non-square DRM, #220 implements a fine, but square DRM.

[ennosigaeus]

This was discussed in today's weekly telco:

OSPEX will only accept a DRM with the same output bins as the count bins. This issue can only be resolved by updating OSPEX to accept non-square DRMs. The version for the fine DRM works for non-square DRMs, but it has never been integrated into OSPEX. The big issue is that other instruments use OSPEX, and the code change is in spec_define and spec_drm_define, the most significant code routines. There is hesitation in modifying those files. Frédéric circumvented this for another routine by copying the relevant code into a new routine with the prefix stx.

Säm argues that OSPEX is at the end of its lifetime; thus, we should be able to make the change.

We will discuss internally if this straightforward way is OK, and then Säm will see if Arun could make the change.