HET End-Trimester Report
Third Period of 2020
August 1 - November 30

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, Engineering, and Guaranteed Time Report There were 292 hours granted for engineering in the 20-3 period:

There were 293.8 hours of eng/comm/GTO used (charged) in the 20-3 period, in the following categories:

In 20-3 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 		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
Aug 0.907
 0.265
 0.624
 0.286
 0.0450
 0.0448
 0.0000
Sep
 0.934
 0.387
 0.658
 0.254
 0.0571
 0.0309
 0.0000
Oct
 0.829
 0.230
 0.651
 0.279
 0.0331
 0.0368
 0.0000
Nov
 0.938
 0.238
 0.620
 0.284
 0.0267
 0.0692
 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
3809
 366.52
 A - Acceptable
69
 17.70
 B - Acceptable but Border line conditions
491
 44.78
 4 - Priority 4 visits (does not include 1/2 charge)
1
 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
0
 0.00
 N - Rejected due to unknown cause
61
 6.43
 E - Rejected for Equipment Failure
199
 40.70
 W - Rejected for Weather
24
 5.70 H - Rejected for Human failure

Uncharged exposures caught by PI
Number of Times Shutter Open (Hours) Type
11
 3.52
 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 5.04
 156.32
 27.55%
LRS2 6.69
 76.93
 27.40%
HPF 7.25
 208.97
 34.07%

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: 293.80h (eng/comm/GTO) + 413.64h (sci) = 707.44h
Total estimated science time available (in TAC time determinations): 670.76h
   Conclusion: weather was better than expectations.




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










G20-3-001 0.30
 0.10
 0.40
 0.40
 100%
 100%


G20-3-002 0.67
 0.22
 0.88
 0.80
 100%
100%

G20-3-003 1.35
 0.38
 1.73
 2.20
 79%

53%
 100%










M20-3-001 1.58
 0.87
 2.45
 2.30
 100%
100%
 100%
M20-3-002 2.75
 0.33
 3.08
 3.00
 100%
100%
 100%
M20-3-003 8.43
 4.01
 12.44
 16.50
 75%
100%
 100%
 37%
M20-3-004 1.65
 0.55
 2.20
 2.00
 100%
 100%












PSU20-3-001 0.00
 0.00
 0.00
 0.50
 0%(P4)



PSU20-3-002 1.60
 0.00
 1.60 6.33 25%(P4)



PSU20-3-003 2.67
 0.48
 3.15
 5.50
 57%


57%
PSU20-3-004 4.00
 0.65
 4.65
 4.66
 100%

100%
 100%
PSU20-3-005 0.00
 0.00
 0.00
 1.93
 0%
TD

PSU20-3-006 8.50
 2.97
 11.47
 13.16
 87%
100%
 100%
 90%
PSU20-3-007 J* J* J* J* J*
J* J* J*
PSU20-3-008 5.40
 0.90
 6.30
 6.50
 97%
100%

PSU20-3-009 2.50
 0.83
 3.33
 3.23
 100%
 100%


PSU20-3-010 4.30
 1.51
 5.81
 6.57
 88%

100%
PSU20-3-011 3.54
 0.95
 4.49
 5.17
 87%
 100%
100%
 50%
PSU20-3-012 0.00
 0.00
 0.00
 0.38
 0%(P4)



PSU20-3-013 1.04
 0.27
 1.32
 5.20
 25%

100%
PSU20-3-014 31.83
 8.22
 40.05
 39.99
 100%
 100%
 100%
 100%
 100%
PSU20-3-015 0.00
 0.00
 0.00
 5.40
 0%(P4,NT)



PSU20-3-016 0.00
 0.00
 0.00
 5.33
 0%(P4)



PSU20-3-017 0.08
 0.00
 0.08
 2.28
 4%(P4)



PSU20-3-018 0.66
 0.00
 0.66
 8.00
 8%(P4)



PSU20-3-019 1.25
 0.30
 1.55
 2.00
 78%
100%
75%










UT20-3-001 5.75
 		1.25
 		7.00
 		10.00
 		70%

100%
 		38%
UT20-3-002 7.71
 1.45
 9.16
 13.00
 70%
100%
 100%
UT20-3-003 0.00
 0.00
 0.00
 2.00
 0%(P4)



UT20-3-004 5.71
 1.87
 7.58
 12.00
 63%


90%
UT20-3-005 J*
 J*
 J*
 J*
 J*
 J*
 J*
 J*
 J*
UT20-3-006 7.67
 1.35
 9.02
 14.00
 64%
 100%
 100%

UT20-3-007 7.53
 1.21
 8.73
 9.50
 92%
100%
 100%
UT20-3-008 5.51
 3.01
 8.51
 14.90
 57%

100%
 100%
UT20-3-009 33.53
 7.34
 40.87
 63.00
 65%
 96%
 98%

UT20-3-010 22.12
 12.05
 34.17
 49.20
 69%

97%
 100%
UT20-3-011 0.75
 0.00
 0.75
 5.00
 15%(P4)



UT20-3-012 7.74
 16.30
 24.04
 41.50
 58%

100%
 83%
UT20-3-013 30.41
 5.61
 36.02
 38.60
 93%
 100%
 100%
 100%
 100%
UT20-3-014 10.32
 3.72
 14.04
 24.60
 57%
100%
 100%
 100%
UT20-3-015 1.60
 1.03
 2.63
 9.50
 28%
100%
 67%
UT20-3-016 8.50
 1.23
 9.73
 10.00
 97%
100%

UT20-3-017 2.53
 1.77
 4.30
 8.40
 51%

100%
UT20-3-018 10.47
 2.60
 13.07
 17.10
 76%
100%
 100%
 98%
UT20-3-019 8.33
 1.10
 9.43
 15.00
 63%


100%
UT20-3-020 5.17
 1.07
 6.23
 16.00
 39%


100%










HET20-3-100 115.50
 39.17
 154.67
 155.00
 99.8%
 100%


HET20-3-201 8.33 1.25 9.58 10.00 96% 100% 100% 100%
HET20-3-300 15.84
 4.11
 19.94
 20.00
 99.7%
 100%
 100%
 100%










Joint prog:
UT20-3-005
PSU20-3-007
 50.11
 10.60
 60.70
 57.97
 100%
 100%
 100%
 100%
 100%










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

J* = joint program between UT, PSU, and Munich - see summary at bottom of table
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 99.7% 100%
P1 99.9% 100%
P2 96.5% 100%
P3 85.2% 98%


Time charged rates (for all science programs): fraction of each priority's allocation actually charged:

Priority
 UT* [h]
chrg/allow
 PSU* [h] chrg/allow
 M [h]
chrg/allow
 G [h]
chrg/allow
 GTO [h]
chrg/allow
   
Percent
P0
 21.51/23.20
 7.53/8.20
 2.20/1.80
 0.40/0.30
 160.08/160.50
98.8%
P1
 67.14/69.40
 19.30/24.70
 6.36/5.60
 0.88/0.80
 10.50/10.60
93.8%
P2
 95.78/92.50
 28.32/33.00
 8.72/7.40
 0.58/1.00
 13.61/13.91
99.5%
P3
 89.88/92.50
 24.12/33.00
 2.89/7.40
 1.15/1.00

88.2%
P4
 31.67
 5.17




*note that time charged to the joint program UT20-3-005+PSU20-3-007 is reported only as UT time in this table




Institution Status

Below we show how the TAC allocations were determined.

quantity
 Aug
(hrs)
 Sep
(hrs)
 Oct
(hrs)
 Nov
(hrs)
 Total
(hrs)
18deg-18deg
 243.93
 268.10
 306.58
 318.17
 1136.78
Weather-insensitive
engineering time
 5.00
 5.00
 5.00
 0.00
 15.00
"Operational" time
 238.93
 263.10
 301.58
 318.17
 1121.78
Weather loss frac. 0.416
 0.504
 0.290
 0.245
Efficiency loss frac.
(align+PRs)
 0.094
 0.098
 0.094
 0.094
"Clear science" time
 126.42
 117.71
 194.00
 217.64
 655.76
Com/Eng/GTO time



252.00
"Allowed" hours
given to TACs
for science



403.76

(note that the HET Operational engineering time allocation of 15h was later increased to 40h in Sept 2020 by the HET Board)


Partner
 Share
 Notes
 Total hours
allowed
Goettingen
 0.0085
3.4
Munich
 0.0590
23.8
PSU
 0.2568
 time trade: 103.69 - 4.75
 98.9
UT
 0.6757
 time trade: 272.82 + 4.75
 277.6

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 20-3 trimester.

Time Allocation by Institution (hours)

Institution Priority 0 Priority 1 Priority 2 Priority 3 Priority 4 Total P0-P3
 Frac. of allowed
Goettingen 0.40
 0.80
 1.10
 1.10
 -
 3.40
 100.0%
Munich 2.00
 6.00
 7.90
 7.90
 -
 23.80
 100.0%
PSU 7.73
 24.76
 33.64
 33.50
 40.67
 99.63
 100.7%
UT 23.10
 69.40
 92.30
 92.10
 139.70
 276.90
 99.7%
Other allocations
GTO 160.5 10.60 13.90 -
 -
 185.00
 100.0%

Notes:
1) PSU knowingly over-allocated beyond their time allowed, but their time charged (across all priorities) did not exceed their 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 (no overhead for priority 4 observations). Recently this calculation was re-derived using a deficit/surplus model. For each financial year the share paid is compared with the time charged - any discrepancy between the two is tracked and carried forward as a deficit. A negative deficit means more time was observed for that partner than their financial share; a positive deficit means less time was observed. These deficits are calculated in each previous financial year; the table below also includes a preliminary total for the current financial year so far.

Accumulated deficits
for each partner
UT
 PSU
 M
 G
 total sci
hours
FY2015-2016
+4.6
 -6.9
 +1.1
 +1.2
 40.49
FY2016-2017
+22.7
 -22.8
 +0.8
 -0.8
 439.56
FY2017-2018
+37.7
 -21.9
 -14.7
 -1.2
 887.71
FY2018-2019
+43.0
 -32.0
 -10.8
 -0.2
 1401.17
FY2019-2020
+48.9
 -48.4
 +0.6
 -1.1
 2101.82
FY2020-2021
including only 20-3
+37.1
 -41.3
 +4.8
 -0.7
 2515.46
*Note that UT's deficit has begun to decrease as a result of pro-actively managing UT PI target submissions and feasibility.
The current 37.1h deficit at UT represents a 1.5% imbalance and will be monitored and tracked to reach as close to 0% as feasible.

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 20-3		 Allocated total
to date
including 20-2 		Charged
in 20-2		 Charged total
to date
including 20-2
HETDEX (HETYY-P-100) 155.0 1821.0 154.67 1279.97
LRS2 GTO (HETYY-P-2XX) 10.0 155.94 9.58 85.19
HPF GTO (HETYY-P-3XX) 20.0 140.40 19.94
 141.31
GW (HETYY-P-400) 0.00 70.00
 0.00
 12.37

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








SJ, Dec 1 2020