NGAO discussion:
Science Operations
NGAO Meeting #4
D. Le Mignant
22 Jan. 2007
Outline
1. Words of introduction on the topic
2. Lessons learned
1.
2.
3.
4.
Weather impact
Efficiency - weather removed
The good things here at Keck
The good things .. elsewhere
3. Top-level goals for science operations
1. Science return
2. Facility-class
3. Long-term operations
4. Observing efficiency (and uptime)
1. Proposed definitions
2. A spiritual agreement
5. Observing models and science data products
1.
2.
3.
4.
6.
Instrument calibrations, maintenance and performance monitoring
Automation and flexibility during the observations
Facility science calibrations
Planning for science beyond our reach
Conclusion and Discussion
2
Science operations:
an important point.. too!
•
Science Operations Design choices have a very major impact:
–
–
–
–
–
•
On the design/cost of the AO/Laser and science instruments
On the observing model for the observers
On the science return
On the observatory budget 2010-2020 (see NSF review)
On the Observatory future priorities
Work in progress
– WBS 2.2.3 Observatory Requirements:
• Science Operations Requirements
– WBS 3.1.1.11 System Design Approach / System Engineering / Performance Budget
• Observing Efficiency and Observing Uptime
– WBS 3.1.2.1.10 System Design Approach / System Engineering / Trade Studies
• Observing Models TS
– WBS 3.4.2 System Design Approach / Science Operations
• AO-Instrument operations
3
Science
Requirements
Observing ScenariosLessons
Learned…
Observatory Rqts
Science Operations
System Design Approach
System Engineering
Performance budget
Trade Studies
Observing Efficiency
Budget
Observing Models
TS
Science Operations
3.4.2.1
AO-instruments Ops
Functional and Performance Requirements
4
Lessons Learned
101 nights of
Keck II LGS AO ops
since Nov. 04 till Jul. 06
5
Lessons learned: weather
•
From our statistic: ~25% of the allocated time
~18 % are entire nights close dome situation
~ 7% marginal weather affecting 1/5 of the open-dome nights
-> Only ~60% of the nights are ~photometric nights
•
Looking at other statistics:
-
Study for New Initiatives AURA office (Erasmus and van Staden)
ESO site search (ESPAS, 2003)
-
-
www.eso.org/gen-fac/pubs/astclim/espas/espas_reports/ESPAS-MaunaKea.pdf
Kaufmann and Vechhione (1981)
Observing quality
Photometric
“Spectroscopic”
unusable
Usable
Frequency of
occurence (%)
45 - 55
17 - 22
20 -25
~ 70-75%
6
Kaufmann and Vecchione (1970-1978)
7
Weather impact:
•
From ESPAS and AURA report on Mauna Kea:
–
Usable nights with LGS < 75%:
•
•
•
–
Photometry:
•
•
–
Seeing is considered the best for the existing astronomical sites (0.5”)
Seasonal trends?
Global warming (long term trend)
•
•
A few nights (~3-4%) are affected by very strong winds
Winds ENE-ESE in the summer, more W and SW in winter
Seeing
•
•
–
Best months are Jan and Feb.
Worst months are October and April
Winds:
•
•
–
About 55% of the nights are >6h of photometric conditions)
An additional fraction 10-15%? are likely usable with LGS (light cirrus)
The maximum of usable time is around 2/3 of the time (240 n/yr)
3.7deg / century for Mauna Loa
Should the science operations takes this information in consideration and study the
feasibility of more flexible schedule?
–
–
Increase observing efficiency
Reduce observing support load (?)
8
Lessons Learned: overheads are too much
1.
2.
3.
4.
5.
6.
7.
Ref: 2006 SPIE papers and some Keck
internal discussion for K1 LGS AO
LGS AO checkout

30min/night
Telescope slew and

pointing
Target ID and centering
LGS AO readiness
5 - 10 min/target
LGS AO optimization
2min per hour on target
Telescope/AO

handshakes
30+ sec per dither
Scientific instrument setup
and readout

Observing strategy
9
Lessons learned: Observing Efficiency
•
•
Keck NGS AO observing efficiency for nights w/o weather or technical
problems at best vary from 25% (snapshot surveys, Lp and Ms obs)
to 60-80% for deep-exposure science programs.
LGSAO shows roughly the same values, except that it is more
impacted by weather and technical problems
For a reliable system in good weather conditions, we are currently
mostly limited by
1. Serial (vs parallel) algorithms (DCS /inst/AO) during observations
2. Under-designed telescope pointing and acquisition systems
3. Under-designed AO nodding/dithering hardware and software
4. Under-designed science instrument readout
5. Aging (WFC) and/or complex instrumentation (laser)
6. Under-designed ancillary systems (photometry, seeing, PSF, etc)
7. Minimal maintenance, calibrations and performance monitoring for
science instruments, AO and laser
8. Operations (Laser traffic rules, overall cost including energetic)
10
Lessons learned: some Keck goodies…
•
A flexible and (rather) small community
–
–
•
Science Instruments
–
–
–
•
Ability for observers to try new observing modes (“push the limits”), and/or calibrate for
problems they discover.
Possibility to script for simple instruments like NIRC2
New generation of observing software with OSIRIS: OPGui and DRP
AO / Laser
–
–
–
•
Ability for observers to combine their observing time
Close interaction between observers and support staff
A best-effort / shared-risk science mode
Ability to optimize (and keep optimizing..), except for the telescope.
Proximity to the instruments for troubleshooting
Community Experience:
–
–
–
Development, integration of new concepts on large telescope (Keck!, LGS, etc)
New-generation of instrument: OSIRIS, etc
Archive (KOA)
11
Lessons learned: other observatories’ goodies
•
A flexible scheduling of the instruments:
–
–
•
Instrument failures has less impact on observing efficiency
Management of observing and eng. time w.r.t. observing conditions
Instrumentation Management
–
–
Strict review for integration, testing and commissioning processes
High-quality maintenance and calibrations
•
•
•
All instruments have maintenance schedules with archived calibrations
Easier traceability of problems/trends
Scientific Operations
–
Integrated operations
•
•
•
–
Facility calibrations
•
•
–
–
–
Automated telescope acquisition (Magic?)
Observing planning tool (obs. seq., AO/inst. config, performance estimate)
Observing sequence templates for instruments / telescope
Flat-field, astrometry, photometry, etc
Ancillary data are archived
Archived science data for long term use
Data reduction pipeline and support.
Service observing ??
12
Science
Requirements
Observing Scenarios
Observatory Rqts
Science Operations
System Design Approach
System Engineering
Performance budget
Trade Studies
Observing Efficiency
Budget
Observing Models
TS
Science Operations
3.4.2.1
AO-instruments Ops
Functional and Performance Requirements
13
Science Operations Goals for the Next Generation
of AO instruments at Keck
(2012 - 2020)
The spirit:
“Maximize the scientific return of the allocated observing time with the NGAO
instruments from 2012 to 2020”
Top-level goals:
1. More than 80% of the time allocated is spent on collecting science-quality data.
2. The NGAO system combined with its science instruments is a facility-class
instrument.
3. The Observatory is capable of supporting the equivalent of 240 nights/year for
NGAO science operations.
…btw, are we including the interferometer?..!-)
14
Some flow-down thoughts
1 - More than 80% of the time allocated should be spent on
collecting science-quality data.
1.
2.
3.
4.
5.
Software should permit simultaneous commands to multiple sub-systems, as well as within a
sub-system
The time allocation method and the Keck science operations model should minimize the
average impact due to lost time from bad observing conditions year-round
A heck of an efficient and skilled astronomer!
> 80% observing efficiency & uptime > 98% ?
Science instrument performance (image quality, sensitivity, observing efficiency and calibration
stability) are documented, simulated, and monitored by the observatory on a routine basis.
1.
2.
3.
6.
The simulation tools should provide key-parameters with a 10 % accuracy within a range of observing
conditions and instrument setup.
The relative astrometry solution error over the field of view should be less than 2% of a pixel. The
pointing and positioning accuracy error on the science field should be known with an error less than
20% of the measured FWHM.
The relative and absolute photometry should be monitored throughout the observations with a precision
of xx % at the observed wavelength.
Etc
15
Some flow-down thoughts
2 - The NGAO combined with its science instruments is
facility-class instrument.
1. Facility-class has many implications on safety, operability, reliability,
maintainability, lifetime, documentation, configuration management, etc.
2. Sustainability
1. Sustainable development program for the instrument?
2. Observatory cost for the operations (including energetic cost)
3. The Mauna Kea laser projection requirements must be satisfied
4. The NGAO installation, integration, testing and commissioning phases
should follow the highest Observatory standards and be reviewed by the
Keck community:
5. Interferometer- & Ohana- related requirements:
a) NGAO should support IF and Ohana science operations
b) The interferometry modes should not require the NGAO light path for optical
alignment in the basement.
16
Some flow-down thoughts
3 - The Observatory is capable of supporting the equivalent of
240 nights/year for NGAO science operations.
1.
2.
3.
4.
Auto-calibration for NGAO performed by non AO-experts.
< 30 minutes of daytime telescope restriction on a science night.
< 30 minutes per observing night for maintenance and science instrument performance calibrations.
Observing tools:
1.
2.
5.
Simulation module (telescope, natural and laser stars) for calibrating and troubleshooting the AO system, as
well as a stable and accurate calibration module (wavelength, flat-field, field distortions, sensitivity) for the
science instruments.
Atmospheric parameters and system diagnostics for image quality monitoring and PSF reconstruction.
A heck of a observing support team:
1.
2.
3.
Expandable and flexible library of observing sequences for each instrument/type of science/etc. Support
astronomer review the observing sequences prior to the observations. The SA will be on-call and may be
present during the observations.
The science instrument should be operated remotely or on-site by one Observer or a Support Astronomer.
The telescope, the AO & laser facility should be operated by two or less Observing Assistants (or equivalent
skills).
17
Science
Requirements
Observing Scenarios
Observatory Rqts
Science Operations
System Design Approach
System Engineering
Performance budget
Trade Studies
Observing Efficiency
Budget
Observing Models
TS
Science Operations
3.4.2.1
AO-instruments Ops
Functional and Performance Requirements
18
Observing Efficiency: we care defining it!
The Observing Efficiency is the open shutter time during dark time when the instrument
runs at the performance level where it is designed to operate, for the given observing
conditions.
•
We care for loss of science return - no matter what!
–
1.
2.
3.
Marginal weather accounting: time loss or not, NGS AO data useful or not, etc
Idea of allocating few nights by TAC: highest ranked proposal gets best conditions,
etc
Understanding observing efficiency for NGAO may require tagging the various sets
of data (science, calibrations, etc).
1.
2.
4.
Observing efficiency is linked to science return during the allocated time (hence weather and
seeing impact should be considered)?
Which part of the calibrations are part of the science-quality data?
Need for facility calibrations
Efficiency per brain cell (the best use of everyone's time by not having to re-invent
the wheel over and over).
19
Observing efficiency and uptime (2)
A spiritual agreement
1. The time allocation method and the Keck science operations model should
minimize the impact due to lost time year-round.
2. Quicker, better slews, setups and moves:
1.
2.
3.
4.
Smaller telescope pointing error (<2 arcsec?), fast telescope slews (xdeg/min).
Faster target acquisition and accurate centering on science array
Faster dither, parallel readout, faster on-line data viewer.
Fast chopper (few Hz) for thermal NIR imaging? Software permits simultaneous
commands to multiple sub-systems, as well as within a sub-system, in order to minimize
time overhead during telescope dither, telescope slew, target acquisition, instrument
setup, instrument data readout, etc.
3. The Observatory manages instrument calibrations & performance at a high-quality
level.
4. The Observatory provides simulation, planning tools, observing templates, etc.
5. The PIs are responsible for performing their observations, given these tools.
•
•
Mean-time-between **any failure mode** should be > 3 hour?
Instrument uptime should remain higher than 98% through the night (12 min)?
20
Science
Requirements
Observing Scenarios
Observatory Rqts
Science Operations
System Design Approach
System Engineering
Performance budget
Trade Studies
Observing Efficiency
Budget
Observing Models
TS
Science Operations
3.4.2.1
AO-instruments Ops
Functional and Performance Requirements
21
Observing Models
Preliminary thoughts…
Scheduling
Mode
Ownership
Mngmnt
Science
Programs
Weather
Impact
Backup
options
Classical
night/night
PI
PI
1 .. 3
flexible
high
NGS AO
NIRSPEC
Night blocks
per TAC
TAC
TAC/Keck
1… 5
flexible
Medium
to
Low
NGSAO
NIRSPEC
DEIMOS
Engin.?
NGAO-only
Queue
PI
Keck
1… 5
flexible
Low
Iden.
Keck
Queue ??
PI
Keck
1..10
Flexible
Low
Iden.
22
Science data-products
Preliminary thoughts…
Science
+ Specifics
Calibration
Support
Ancillary
data
Data
reduction
Archive
Monitoring
Classical
observer
Observer
no
minimum
No
So-so
Plus
Observer
Observer
Archived
Yes
minimum
Calibrations
Advanced
Observer
Observatory
Yes
Minimum
calibrated
Cals+science
performance
Service
Observatory Observatory
Yes
calibrated
Cals+science
performance
23
Conclusion
•
Next steps:
1.
Help build the Observing Scenario Spreadsheet
2.
Discussion and feedback: observing modes and science operations are not very well
documented.
3.
Propose to delay:
1.
2.
4.
From the WBS Dictionary (3.4.2.1): Define the overall architecture, the method and design the
interfaces for operating the sub-systems of the NG AO-instrumentation. Here AO-instrument
refer to AO, laser, SC, science instrument, etc.
Discuss operations team's strategy for structuring the remainder of the SD phase tasks under
3.4.2.1
More work in many areas. One main challenge: coordinating the work with Keck and
the science community, while staying in the numbers of allocated hours.
24