HET Beginning-Trimester Report
  Third Period of 2024
August 1 - November 30

This report is primarily to give updates to PIs on recent changes/improvements and to summarize the determination of time allocations for the 24-3 trimester.


*N.B., this report is being prepared earlier than usual (January 2024) by current science operations manager, S. Janowiecki, before resigning at the end of January.


Updates on recent changes/improvements:

Collecting Efficiency

   Priority 0 fractions have returned to their pre-HETDEX levels, with Pr0 = 8.33% and Pr1 = 25%.      (In 2022 the HET Board approved a proposal from the HET Users Committee to change these to 13.33% and 20%.)

Collecting Efficiency

    We continue to work towards implementing a significant improvement to the Phase II Target Submission Language parameterization of sky transparency.  [updates?]








Commissioning, Engineering, and Guaranteed Time allocations


The HET Board granted the following allocations for the 24-3 period:



 





Breakdown of how science hours for TACs at each partner were determined:



quantity
 Aug
(hrs)
 Sep
(hrs)
 Oct
(hrs)
 Nov
(hrs)
 Total
(hrs)
18deg-18deg times
 243.93
 268.10
 306.58
 318.17
 1136.78
Weather loss frac. 0.44
 0.46
 0.35
 0.37
Efficiency loss frac.
(align+PRs)
 0.07
 0.07
 0.07
 0.07
"Clear science" time
 127.04
 134.64
 185.33
 186.41
 633.42
Com/Eng/GTO time
 *time granted by Board



20
"Allowed" hours
given to TACs
for science



613.42
*with correction factor based on typical fraction actually utilized



 

Hours allowed for each TAC as determined Jan __, 2024:


Partner
 Share
 Time deficit
correction
 Total hours
allowed
Allocated
as of Aug 1
(excl. Pr4)
Goettingen
 0.03860
 +0.30
 23.98
 tbd
Munich
 0.05724
 +1.50
 36.61
 tbd
PSU
 0.24897
 -7.20
 145.52
 tbd
UT
 0.65518
 +5.40
 407.30
 tbd
*includes 0h removed for TESLA

Corrections were applied using 75% of the cumulative deficits in time balance between the partners. As of Dec 1 2023, those time deficits were:
  UT:   7.2h deficit
  PSU: 9.6h surplus
  M:     2.0h deficit
  G:     0.4h deficit
Actual time usage is carefully monitored to ensure equitable balance between the partners; these corrected allocations should help improve this balance over the long-term.
 
Note that 24-3 is the first trimester to return to the pre-HETDEX Priority 0 breakdown, with Pr0 time at 8.33% and Pr1 time at 25%. For more details see here. 



TAC estimates
Pr0
 Pr1
 Pr2
 Pr3
2.0
 6.0
 8.0
 8.0
 Goettingen
3.1
 9.1
 12.2
 12.2
 Munich
12.1
 36.4
 48.5
 48.5
 PSU
33.9
 101.8
 135.8
 135.8
 UT






SJ, X Jan 2024