[INSTRM-37] Finalize exposure time sources and keywords Created: 17/Dec/16  Updated: 05/Apr/17  Resolved: 09/Jan/17

Status: Done
Project: Instrument control development
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Task Priority: Major
Reporter: cloomis Assignee: arnaud.lefur
Resolution: Done Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Reviewers: cloomis

 Description   

We have a proposed mechanism for establishing the exposure time and duration values, but need to make all the actors agree.

  • the ENU actors (specifically the shutter control) establish the absolute exposure start time (based on some point in the shutter opening process) and the exposure length (based on the shutter closing and the previously decided open time).
  • the CCD actor read command will be passed those as "exptime=S.SS" and "dateobs=string".

ISO format, UTC.

Questions:

  • What FITS keys to generate?
  • what to do about bias and dark readouts? I think that the dateobs argument should be optional and the exptime argument disallowed or ignored.

 Comments   
Comment by shimono [ 17/Dec/16 ]

Is this for AIT work or the final? If final, we also need to have a place for NCU actor...

For FITS keyword, limiting only to datetime ones,

  • EXPTIME for exposure time
  • HST, HST-STR, HST-END, LST, LST-STR, LST-END for local time
  • MJD, MJD-STR, MJD-END for MJD
  • UT, UT-STR, UT-END for UT

For dark or bias, normally

  • set DATA-TYP as 'BIAS' or 'DARK'
  • set EXPTIME as 0 or exposure time of dark
  1. check https://pfs.ipmu.jp/pipermail/instrument-software/attachments/20161011/3cee2e9c/attachment.xlsx for extended list.
Comment by arnaud.lefur [ 09/Jan/17 ]

The keywords dateobs and exptime are now generated by the bsh controller.
This event occurs after :

  1. Interlock checking and transition validation
  2. "shut_open" NTR
  3. "shut_close" NTR

See commit b8cb5b9

Comment by cloomis [ 09/Jan/17 ]

That scheme works for me. But please reassure me that those keywords are always generated before the CCD readout is called for.

Comment by arnaud.lefur [ 09/Jan/17 ]

Yes, they must have been generated before.
It's the sequencer job to get and check those information and then parse them as a argument to the ccdActor read command.

Comment by arnaud.lefur [ 17/Jan/17 ]

I've added
exptime = cmdKeys['exptime'].values[0] if 'exptime' in cmdKeys else None
in the 2016-11-30 version to be able to have exptime in FITS header

Generated at Sat Feb 10 16:20:51 JST 2024 using Jira 8.3.4#803005-sha1:1f96e09b3c60279a408a2ae47be3c745f571388b.