[INSTRM-731] Decide on content of H4 ramp time cards. Created: 15/Aug/19 Updated: 25/Mar/21 Resolved: 25/Mar/21 |
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| Status: | Done |
| Project: | Instrument control development |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Task | Priority: | Normal |
| Reporter: | cloomis | Assignee: | Hisanori Furusawa |
| Resolution: | Done | Votes: | 0 |
| Labels: | FITS, SPS | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Story Points: | 1 |
| Sprint: | SM1PD-2020 M, SM1PD-2020 N, SM1PD-2021 A, SM1PD-2021 A 2, SM1PD-2021 A 3, SM1PD-2021 A 4, SM1PD-2021 A 5 |
| Description |
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What does Subaru want for the H4RG ramp time cards? The PHDU can only know about the starting time stamp: should it only have MJD-STR cards (using MJD as the example one of MJD,HST,UT,LST)? Could also make the case for using straight MJD cards instead of MJD-STR cards. The per-read HDUs can obviously know about their start and end times; should they each have MJD-STR, MJD, MJD-END or is that silly and/or conflicting? Note that the times themselves would be boringly predictable: they will be calculated from the ramp start and the ramp time, and not by asking a clock for the time. Do we want -END cards for the entire ramp? Would that go into the last read's HDU, or would we add a post-ramp HDU for summary/"at-end" cards? |
| Comments |
| Comment by Hisanori Furusawa [ 15/Aug/19 ] |
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What is the data format for the ramp data? Do they come into a multiple HDUs or separate FITS? MJD is a common but *-STR and *-END are optional, so in general, if the instrument team thinks them unnecessary, they simply put MJD (and the other common counterparts UT, LST, ...) only. If *-STR, *-END are helpful for something, it would be good to put them as well. Coexistence of all three keywords is no-silly and a typical case for the existing instruments. Which HDU they should go in? I'd like to hear @monodera's comment from a FITS policy point-of-view, but I don't think that having these important keywords in every IMAGE HDU is a bad idea. |
| Comment by cloomis [ 15/Aug/19 ] |
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For the PFSB ramp files, one HDU per read. |
| Comment by cloomis [ 23/Aug/19 ] |
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If we know both start and end times we will have, for each of MJD, LST, HST, UT, a MJD-STR, MJD, MJD-END card. Easy. What card should there be if we only know the start time? If we use MJD, then the meaning of that card is "start of exposure" in some headers, and "middle of exposure" on others. So MJD-STR? |
| Comment by hassan [ 25/Mar/21 ] |
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Implemented as proposed. |