HET End-Trimester Report
Second Period of 2020
April 1 - July 31

This report is composed of five sections:
Facility Status

In this section we will discuss the status of the HET facility and each instrument and any limitation to configurations that occurred during the period.



Observing Statistics

Commissioning and Engineering Report There were 128 hours granted for engineering in the 20-2 period:

There were 64 hours of engineering used (charged) in the 20-2 period, in the following categories:

In 20-2 the engineering, commissioning, and GTO requests were again collected by the Science Operations Manager, and presented to the board. After the board approved these "off the top" allocations, the Science Operations Manager determined the TAC allocations and notified the TAC chairs at each partner institution, as described in the "Institution Status" section.




Month by Month Summary

The following table gives the observing statistics for each month. Column A gives the fraction of the month that was spent attempting science (as opposed to engineering or instrument commissioning). Science time is defined to begin at 18 degree evening twilight and end at 18 degree morning twilight. Column B gives the fraction of the possible science time (A) lost due to weather. The other columns give the amount of remaining science time (after removing weather losses) not spent attempting science targets. Please note that the first stack of the night often occurs before 18 degree twilight.

Month A:
Fraction of the Time that was Possible Science 		B:
Fraction of Total Time Lost due to Weather
*now w/ rej targ
 C:
Fraction of Actual Science Time Spent with Shutter Open 		D:
Fraction of Actual Science Time Lost due to Overhead 		E:
Fraction of Actual Science Time Lost due to Alignment		 F:
Fraction of Actual Science Time Lost due to Problems		 G:
Fraction of Actual Science Time Not accounted for or Lost
Apr
 0.906
 0.372
 0.664
 0.266
 0.0314
 0.0388
 0.0000
May
 0.846
 0.279
 0.645
 0.268
 0.0754
 0.0120
 0.0000
Jun
 0.882
 0.430
 0.625
 0.262
 0.0589
 0.0542
 0.0000
Jul
 0.879
 0.487
 0.626
 0.283
 0.0491
 0.0415
 0.0000

The following tables give a break down of all attempted science visits as well as the category that each falls into.

Charged exposures
Number of Times Shutter Open (Hours) Type
2661
 366.52
 A - Acceptable
87
 17.70
 B - Acceptable but Border line conditions
149
 44.78
 4 - Priority 4 visits (does not include 1/2 charge)
0
 0.0 Q - charged but PI error
0 0.0 C - Acceptable by RA but PI rejects

Uncharged exposures caught by RA
Number of Times Shutter Open (Hours) Type
3
 0.52
 N - Rejected due to unknown cause
6
 1.98
 E - Rejected for Equipment Failure
198
 44.47
 W - Rejected for Weather
5
 1.27 H - Rejected for Human failure

Uncharged exposures caught by PI
Number of Times Shutter Open (Hours) Type
20
 6.62
 P - Rejected for weather
0 0.0 F - Rejected for Equipment Failure
0 0.0 T - Rejected for poor track choice
0 0.0 X - Rejected for Human failure

Acceptable but Uncharged exposures
Number of Times Shutter Open (Hours) Type
0
 0.0 I - Targets observed under otherwise idle conditions

The following setup statistics include slew, acquisition, and starting data collection script. The table below gives the average setup time for each instrument PER ACTUAL VISIT and the average and maximum COMPLETED charged science exposures and visits.

The "Exposure" is defined by when the (CCD) shutter opens and closes. A "Visit" is the requested total CCD shutter open time during a track and might be made up of several "Exposures". "Visit" as defined here contains no overhead. To calculate one type of observing efficiency metric one might divide the "Visit" by the sum of "Visit" + "Overhead".

The average setup per visit is calculated from acceptable priority 0-3 (not borderline) science targets. This number reflects how quickly we can move from object to object on average for each instrument, however, this statistic tends to weight the setup for programs with large number of targets.

The average overhead percentage is calculated for each instrument and shows how much of that instrument's total time on sky (overhead+exposure) was overhead. NB: LRS2 has the smallest overhead %, but typical LRS2 observations use much longer exposures than VIRUS, even though VIRUS has a faster average setup time.

Instrument Avg Setup per Visit
(min)		 Total time exposed
(hrs)		 Overhead
%
VIRUS 4.38 166.6
 23.43%
LRS2 7.97
 47.25
 31.93%
HPF 7.29
 107.73
 33.31%

The setup statistics can be shortened by multiple setups (each one counted as a separate visit) while on the same target such as moving from LRS2-B to LRS2-R.


HETDEX time interruptions:

Within the times when HETDEX shots were available on-sky for >20 minutes, the following percentages summarize how the time was used:


Overall time charged: 376.7h (science/GTO) + 103.5h (eng) = 480.2h
Total estimated science time available (in TAC time determinations): 500.7h


Observing Programs Status

In the table below we show the breakdown of the charged time for each program submitted. The "Total %" is the completion of the entire TAC time including P4 time. The last four columns show the completion rate for targets submitted in each priority bin. This completion rate is the greater of the targets completed percentage and the TAC allocation completed percentage in each priority bin.
Institution Tot exp
 Tot OH
Tot Chrg Tot TAC Total % P0 Completion
 P1 Completion P2 Completion P3 Completion










G20-2-001 0.40 0.15 0.55 1.00 55%

100%
 0%
G20-2-002 0.39 0.06
 0.45 0.50
 90%
90%











M20-2-002 1.28
 0.39
 1.67
 3.90
 43%
 100%
 100%
 0%
M20-2-003 0.96
 0.67
 1.63
 5.60
 29%
79%
 76%
 0%
M20-2-004 0.83
 0.32
 1.15
 1.00
 100%
100%











PSU20-2-001 2.63
 0.59
 3.21
 2.67
 100%
 100%
 100%
 100%
 100%
PSU20-2-002 0.33
 0.15
 0.48 0.53 91%
100%

PSU20-2-003 2.17
 0.28
 2.45
 2.66
 92%
 100%
 100%

PSU20-2-004 2.10
 0.42
 2.52
 2.50
 100%
100%
 100%
 100%
PSU20-2-005 0.08
 0.00
 0.08
 0.54
 15%(P4)



PSU20-2-006 2.11
 0.50
 2.61
 2.67
 82.5%

100%
 100%
PSU20-2-007 0.00
 0.00
 0.00
 0.84
 0%(P4)



PSU20-2-008 0.00
 0.00
 0.00
 0.33
 0%(P4,NT)



PSU20-2-009 0.13
 0.00
 0.13
 1.00
 13%(P4)



PSU20-2-010 23.63
 5.89
 29.52
 30.00
 98%
 100%
 100%
 100%
 100%










UT20-2-002 0.17
 0.00
 0.17
 2.00
 8%(P4)



UT20-2-003 2.76
 0.69
 3.45
 10.00
 25%
 100%
 100% TD

UT20-2-004 4.08
 0.87
 4.95
 18.00
 28%


90%
UT20-2-005 0.25
 0.00
 0.25
 2.00
 13%(P4)



UT20-2-006 7.29
 3.09
 10.38
 20.60
 50%


95%
UT20-2-007 21.34
 4.80
 26.14
 33.00
 79%
100%
 100%
 100%
UT20-2-008 10.80
 3.85
 14.65
 32.00
 46%
100%
 100%
 33%
UT20-2-009 8.93
 0.00
 8.93
 15.00
 60%(P4)



UT20-2-010 11.67
 6.42
 18.09
 31.70
 57%

100%
UT20-2-011 30.40
 8.45
 38.85
 56.40
 69%
 100%
 100%
 100%
UT20-2-012 2.43
 1.36
 3.79
 7.40
 51%

100%
UT20-2-013 1.83
 0.00
 1.83
 2.00
 92%(P4)



UT20-2-014 1.27
 0.71
 1.98
 2.00
 99%
100%
 100%










HET20-2-100 130.80
 48.08
 178.88*
 187.00
 96%
 100%


HET20-2-201 5.50 0.75 6.25 6.37 98% 100% 100% 100%
HET20-2-202 2.67
 0.97
 3.63
 3.63
 100%
 100%
 100%

HET20-2-300 15.67
 4.27
 19.94
 20.00
 100%
 100%
 100%
 100%
HET20-2-400 0.00
 0.00
 0.00
 17.50
 0%
 NT






















Institution Tot. Open
 Tot OH
 Tot Chrg
 Tot TAC
 Total %
 P0 completion
 P1 completion
 P2 completion
 P3 completion

NT = no (or very late-in-trimester)targets submitted at this priority (even though time was allocated)
HC = HETDEX conflict (targets submitted were in direct competition with HETDEX; PI was aware of issue)
SI = Seasonally inappropriate (target had limited availability during trimester because of twilights)
TD = Time Domain targets (either none submitted or submitted targets unreachable due to weather)
* = HETDEX nominal exposures+overhead at 178.88h but total on-sky time was 187.0h due to OCD's exposure extensions



Program Completion Rates
Priority Average Completion Median Completion
P0 100.0% 100%
P1 98.2% 100%
P2 91.7% 100%
P3 71.8% 98%


Institution Status

Below we show how the TAC allocations were determined.


quantity
 Apr
(hrs)
 May
(hrs)
 Jun
(hrs)
 Jul
(hrs)
 Total
(hrs)
18deg-18deg
 248.20
 224.58
 199.88
 215.15
 887.82
Weather-insensitive
engineering time
 5.00
 5.00
 5.00
 5.00
 20.00
"Operational" time
 243.20
 219.58
 194.88
 210.15
 867.82
Weather loss frac. 0.320
 0.320
 0.380
 0.480
Efficiency loss frac.
(align+PRs)
 0.081
 0.081
 0.089
 0.100
"Clear science" time
 152.43
 138.23
 110.78
 99.30
 500.74
Com/Eng/GTO time



323.00
"Allowed" hours
given to TACs
for science



177.74

(note that HETDEX's allocation of 185h was later increased to 187h in July 2020 by the HET Board)



Partner
 Share
 Notes
 Total hours
allowed
Goettingen
 0.0085
1.49
Munich
 0.0590
10.49
PSU
 0.2568
 time trade: 92.24 - 4.75
 40.89
UT
 0.6757
 time trade: 242.70 + 4.75
 124.85

TACs may allocate up to 8.3% at P0, 25% at P1, 33.3% at P2 and 33.3% at P3. P4 allocations are not restricted. GTO and engineering time are assigned by the HET board and not from this formula.


This is how each institution had allocated its time by priority in the 20-2 trimester.

Time Allocation by Institution (hours)

Institution Priority 0 Priority 1 Priority 2 Priority 3 Priority 4 Total P0-P3
 Frac. of allowed
Goettingen -
 0.50
 0.50
 0.50
 -
 1.50
 100.0%
Munich 0.90
 2.60
 3.50
 3.50
 -
 10.50
 100.0%
PSU 3.33
 11.03
 13.33
 13.34
 3.21
 41.03
 100.3%
UT 10.40
 32.00
 42.10
 42.16
 110.00
 127.10
 101.8%
Other allocations
GTO 210.5 12.00 12.00 -
 -
 234.5
 100.0%

Notes:
1) PSU intentionally over-allocated their P0 and P1 time; in early July the time charged exceeded its time allowed at P2 and P3 and therefore all remaining high-priority time was prematurely deactivated
2) UT also over-allocated its time, but its time charged did not exceed the time allowed





The following is a summary of the total charged time for each institution based on our htopx data base (for shutter open) and night reports (for overhead). It includes shutter open time (weighting priority four by half) and overhead.

As requested by the board the time accounting has started over starting Fiscal year 2011-2012.

Time Charged by Institution (hours)
-INST- Hours charged
this period
(% allowed)
 % of all
this period
 Total hours charged
to date
including 20-2		 % of all
to date
including 20-2 		Partner shares
in 20-2
Goettingen 1.00 (67%)
 0.6%
 185.58
 3.6%
 0.84%
Munich 4.45 (42%)
 2.5%
 249.45
 4.8%
 5.90%
PSU 41.01 (100%)
 22.8%
 1480.08
 28.4%
 25.68%
UT 133.46 (107%)
 74.2%
 3301.46
 63.3%
 67.57%
NB: a more comprehensive annual partner fractional time charging analysis is produced separately from these trimester reports; a current copy can be provided upon request.



Below are the summaries of the Guaranteed Time Observations (GTO) programs granted by the Board:

GTO and Special Time Charged by Project (hours)
Project Allocated
in 20-2		 Allocated total
to date
including 20-2 		Charged
in 20-2		 Charged total
to date
including 20-2
HETDEX (HETYY-P-100) 187.0 1666.0 178.88 1125.3*
LRS2 GTO (HETYY-P-2XX) 10.0 145.94 10.00 75.61
HPF GTO (HETYY-P-3XX) 20.0 120.40 19.94
 121.37
GW (HETYY-P-400) 17.5 70.00
 0.00
 12.37
*HETDEX time charged uses nominal exposure times, not OCD-extended times

(Totals to date start from the 11-2 period)








SJ, Aug 7 2020