Telescope and Instrument Performance
Summary (TIPS)
15 August 2002
AGENDA
1.
2.
3.
4.
5.
6.
SMOV3B Summary
HST Metrics
ACS Status
NICMOS Status
STIS Status
WFPC2 Status
Carl Biagetti
Ron Downes
Mark Clampin
Daniela Calzetti
Jeff Valenti
Lori Lubin
Next TIPS Meeting: 19 September 2002
Carl Biagetti
TIPS 15Aug02
CURRENT SMOV3B STATUS
• SMOV ACCOMPLISHMENTS TO DATE
– Spacecraft Subsystems
• Recommissioned in March
– STIS
• SMOV completed in early May
– WFPC2
• SMOV completed in early April
– ACS
• SMOV completed - last activity 21 July
– Coronagraphic ERO visit
Carl Biagetti
TIPS 15Aug02
CURRENT SMOV3B STATUS
• SMOV REMAINING
– NICMOS
• Coronagraph optimization (8984)
– SMS231 Visits 14-2Z (last SMOV visits)
– October – Visits 1-3 (booked as Cycle 11 calibration)
– EPS
• Battery 1 capacity test
– SMS231
Carl Biagetti
TIPS 15Aug02
SMOV3B PROGRESS
TOTAL
SCHEDULED
ACTUAL
PERCENT
PLANNED
COMPLETIONS
COMPLETIONS
COMPLETE
as of 14 AUG
as of 14 AUG
ACTIVITIES
by 14 AUG
EXTERNAL
ORBITS
(total SMOV)
SPACECRAFT
20
20
20
100.0
22
ACS
30
30
30
100.0
171
ERO
3
3
3
100.0
87
NCS
2
2
2
100.0
0
NICMOS
21
21
20
95.2
75
STIS
10
10
10
100.0
14
7
7
7
100.0
31
WFPC
FGS
TOTAL
5
5
5
========
98
========
98
========
97
100.0
========
99.0
19
========
419
Carl Biagetti
TIPS 15Aug02
SMOV3B RESOURCES
• Observatory Resources
– Total external orbits = 419
• Not including 2-week BEA pointing
• SMOV Team
– STScI/GSFC/IDT/Ball
– Job well done, many long hours, not a “routine” SMOV
– 51 “morning meetings” Mar12 to Jul24 (165 days)
• average of one meeting every 63.5 hours (daily 1st 2 weeks)
Carl Biagetti
TIPS 15Aug02
POSSIBLE OPERATIONAL
CHANGES (Spacecraft)
• Electrical Power System (EPS)
– Sun Incidence Angle constraint may be relaxed
• Since SA3 provides more power
– May involve sw upgrade but no science
impacts
• Thermal Control System (TCS)
– Off-nominal roll constraint may be made more
restrictive
• Needed because Bay 5 is warmer post-3B due to
higher data volumes (SSR & xmitter usage)
• No significant impact to Cycle 11 yet identified
Carl Biagetti
TIPS 15Aug02
SMOV LESSONS LEARNED
• Lessons Learned document in work
–
–
–
–
Lessons
Lessons
Lessons
Lessons
1- 6
7 – 10
11 – 15
16 – 17
SI Operations
Flight Ops
Data Processing
SMOV Planning and
Ground Testing
• To be finalized by 30 Aug.
– Will be included in SMOV Closure Review
Carl Biagetti
TIPS 15Aug02
PLANS
• SMOV Closure Review
– 30 Sep. 02, 1-4 pm, STScI Auditorium
– Assessment of original SMOV3b requirements
– Final documentation of lessons learned
• SMOV4 Requirements
– Sep. 02 - Analysis phase begins
– Assuming early-mid 2004 launch
TIPS Meeting
SPACE TELESCOPE SCIENCE INSTITUTE
15 August 2002
Ron Downes
HST Operational Metrics Page
Who makes it?
Curator: Ron Downes
Infrastructure and design: ITT Group (Mike Wiggs, Matt Lallo, Anne Gonnella,
Leigh McCuen)
Data Providers: Sara Anderson, Brett Blacker, Ron Downes, Karen Levay, Shelly
Meyett, Sid Parsons, Merle Reinhart, SI Groups
What is it?
• contains metrics/statistics on HST operations (from proposal selection to data
retrieval)
• presently 16 pages, ~40 planned
• some external, some internal only (all now internal)
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TIPS Meeting
SPACE TELESCOPE SCIENCE INSTITUTE
15 August 2002
Ron Downes
When is it available?
• as of August 12, 2002
Where is it?
• http://www.stsci.edu/hst/metrics
• documentation (including planned pages) available
How does it work?
1) data creation:
• data is created by page owners
• in many cases, a database query followed by Excel processing to make plots
• data copy to anonymous ftp site for ingest
• creation of many datasets can be automated (several already are)
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TIPS Meeting
SPACE TELESCOPE SCIENCE INSTITUTE
2) data ingest/page generation
• data grabbed from ftp site
• pdf files, thumbnails, and related products created
• metadata assigned to the files then loaded into Zope
• page generated on-the-fly
• totally automated
15 August 2002
Ron Downes
3
TIPS Meeting
SPACE TELESCOPE SCIENCE INSTITUTE
Homepage
List of
available
pages
more to come
15 August 2002
Ron Downes
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TIPS Meeting
SPACE TELESCOPE SCIENCE INSTITUTE
15 August 2002
Ron Downes
Sample page
History
Description
Data
Data
Download
Source
internal only
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TIPS Meeting
SPACE TELESCOPE SCIENCE INSTITUTE
15 August 2002
Ron Downes
Pages of interest to Instrument Teams:
Calibration Plan - high-level summary of calibration plan
SI Usage - Phase II proposal statistics on instrument usage by SI
Selection Statistics - Phase I selection statistics
Calibration Programs - calibration program execution/analysis status
Pages of interest to PC and Scheduling Teams:
Cycle Statistics - overall status of program execution
Failed Observations - summary of failed observations
Parallel Programs - status of parallel program execution
SNAP Programs - status of SNAP program execution
ToO Programs - status of ToO programs
Data Volume - summary of SSR usage by SMS
6
SMOV
ACS has now completed SMOV Program
– Transitioned to interim calibration plan
Final SMOV programs
– Further coronagraph calibration
– Coronagraph EROs
Analysis by John Krist
Variations with Wavelength
F814W
Large Spot
F606W
Small Spot
F435W
SMOV
Results
– Occulter positions are stable (< 2 mas) on
orbital timescales when the masks are kept in
place.
– Spots can shift by up to 6 mas between
acquisitions (mostly in Y direction).
Proposed commanding changes
– Target acquisition with coronagraph in place
– Do not shutter with aperture door between
alignments.
• Provided mirror protection during SMOV
Calibration
New flat fields have been installed for WFC
– Precision ~1%
– Further improvements require skyflats
– Require enough images for high S/N
Current priorities
1. HRC broadband flat fields (***)
2. HRC NUV earth flat fields (**)
3. Grism flats (ECF) (*)
4. SBC flat fields (*)
5. WFC/HRC Earth flats (UV & narrowband filters)
(***)
WFC Sensitivity
Corrections to existing WFC synphot tables (based
on GD71 and GRW70)
– Filter
Factor
– F435W
1.23
– F475W
1.23
– F555W
1.16
– F606W
1.13
– F625W
1.13
– F775W
1.11
– F814W
1.09
1.02
– F850LP
WFC Sensitivity
HRC Sensitivity
SBC Sensitivity
Geometric Distortion
Need 4th order solution to meet 0.2 pix accuracy
requirement.
– rms <~ 0.05 pix all frames & detectors
– Breathing effects <~ 0.1 pixels across WFC
FOV
– No color terms needed
King’s calibration proposal will provide final check
of skewness
– King expects 10x nominal IHB calibration
– Handle stitching errors etc.
Bootstrap SBC check from HRC results.
CALACS/
PyDrizzle
CALACS/PyDrizzle
CALACS Version 4.1a (26-July-2002) and
PyDrizzle Version 3.3 (12-Aug-2002) have been
delivered to OPUS/DST for testing under
OPUS14.1.
For CALACS 4.1a:
– ACSREJ now correctly computes the error
arrays and initial guess image
For PyDrizzle 3.3:
– supports newer higher-order polynomial fits from
IDCTAB
CALACS/
PyDrizzle
CALACS/PyDrizzle
– Allows 'blot' and single-exposure drizzling
– This enables tasks to be written to remove cosmic-rays
using PyDrizzle, with 'multidriz' being the alpha-version of
such a task.
– Correctly computes (small) offsets by applying distortion
to input WCS. This will dramatically improve the
registration in OTFR products for a wide range of dithered
observations.
– Provides ability for arbitrary specification of output frame.
Allows users to PyDrizzle their data for direct comparison
with reference/ground-based/astrometric observations
ACS CTE Degradation: I
• Analysis of cosmic ray profiles: Riess
WFPC2 CTE Degradation
ACS Data Access
ACS Group
Welcome to two new group members
– Shardha Jogee
– Roland van der Marel
Chris O’Dea is moving to SPD
NICMOS Status
Daniela Calzetti
Presentation for TIPS, 08/15/2002
Instrument Status
NICMOS detectors’ temperature continues to be stable under
NCS control
Default plan is to tweak NCS control temperature as
needed to keep detectors at constant T, should it become
necessary.
Old habits…
On July 23rd, an Intel exception caused NICMOS to suspend. A
few parallel exposures (GO-9484) were lost.
Two SEUs caused TPG resets in NIC1 (July 31st) and NIC3
(Aug. 11th), with consequent powering off of the affected detectors.
In the first instance, no NICMOS exposures were lost. In the
second, one exposure (possibly 2) of GO-9484 affected.
NCS/NICMOS Temperature
B, I, Hα
C. Long 08/15/02
J, H, Pα
NICMOS SMOV3B
Almost done ….
The remaining program, ID 8984 `Coronographic
Performance Test’ (6 orbits), due to execute in early August,
was delayed due to higher priority GO science;
Three orbits will execute in the week of August 19th
(SMS231).
Three orbits delayed until October because of target
unavailability; these observations re-determine the position
of minimum scattered light under the coronograph (`sweet
spot’). Carl Biagetti asked to move these three orbits to
Cycle 11 calibrations and TTRB approved on 08/13/02.
Officially NICMOS SMOV3B ends in late August.
NICMOS Characterization: DQE
From standard star P330E:
From flat-fields:
Ratio of Cal Factors
Boeker/Mazzuca
M. Rieke
2.00
NCS/Pre-NCS
1.80
1.60
1.40
1.20
1.00
0.80
0.8
1.0
1.2
1.4
1.6
1.8
2.0
??? m)
Camera 1 Camera 2 Camera 3
Flat-fields and standard star measurements show consistent
increase in DQE from 62 K to 77 K (~60%-70% at 1 µm and
~20%-25% at 2 µm)
2.2
2.4
NICMOS Characterization: DQE
Absolute DQE,
derived from %
increase (see
previous slide)
applied to
Thermal
Vacuum data
WFPC2 B,V,I
NICMOS J,H,PαBoeker/Mazzuca
Preliminary NICMOS photometric keywords (PHOTFNU)
delivered by M. Rieke (08/08/02)
NICMOS Characterization: dark current
L. Bergeron
Linear dark current
only is 0.1-0.2 e-/s/pix,
about 3-4 times higher
than in Cycle 7/7N.
N.B.: as usual, the
amplifier glow (NREADdependent) adds to the
noise budget.
Plan is to advertize 0.3 e-/s/pix in ETC and Instrument
Handbook for S/N calculations. However, NICMOS
observations are generally not dark current-limited.
High DarkCurrent Pixels
in NICMOS
L. Bergeron
Dark frames:
A longer tail of high dark
current pixels than in
Cycle 7/7N (few % of
total pix).
Fully correctable.
Some high d.c. pixels
will saturate earlier in
the presence of bright
targets.
Additional On-going Characterization
Readout noise appears to be slightly lower than the
customarily advertised 30 e-/pix/readpair. Possibly closer to 2627 e-/pix/readpair (Boeker/Xu)
Detector’s linear dynamic range (<10% non linearity) is about
10% lower than Cycle 7/7N, as expected (Boeker/Sosey)
Number of hot/cold pixels about 50% higher than in Cycle
7/7N, now being ~110-150 pixels, depending on the Camera
(Bergeron). New large piece of grot appeared in NIC1 (Sosey)
Torpedo
Cycle 7 NIC1
Cycle 11 NIC1
Need to ensure
instrument’s
thermal stability
Pipeline/Data Analysis
NICMOS OTFR is running Temp-dependent darks since last
April.
Pipeline still running Cycle 7/7N reference files.
13/19 (NIC1), 15/19 (NIC2), 19/19 (NIC3) Cycle 11 flat-fields
delivered to CDBS. Awaiting installation. Data for remaining in
hand (Mazzuca)
Preliminary Dark Reference files (Temp-independent)
circulated among NICMOS group (08/14/02, Bergeron). In
testing.
Post-SAA CR persistence analysis started. Preliminary analysis
indicates no change in CR decay time relative to Cycle 7/7N
(Dickinson/Sosey)
STIS Status:
MSM Monthly Offsets for Echelles
Outline:
ƒ Echelle Wavelength Calibration Errors
ƒ Echelle Flux Calibration Errors
ƒ Disabling MSM Monthly Offsets
Aug 15, 2002 TIPS
Jeff Valenti
Echelle Wavelength Calibration
ƒ Calstis 2.10 Methodology
ƒ
ƒ
ƒ
ƒ
Shift canonical solution to match auto-wavecals
Relative precision goal: 0.25 - 0.5 pixel
Absolute accuracy goal: 0.5 - 1.0 pixel
Limited by thermal stability, geometric distortion, etc.
ƒ Effect of MSM Monthly Offsets
ƒ
ƒ
ƒ
ƒ
Preserve MAMA sensitivity throughout mission
Spectra shifted by a few pixels each month
Monthly offsets also distort wavelength solution
Relative precision goal not always achieved
ƒ Achieving Calibration Goals
ƒ Old data: Calstis 2.12 includes Lindler dispersion algorithm
ƒ New data: No offsets for echelles as of Aug 5, 2002
ƒ ECF working on physical model of STIS
Echelle Wavelength Errors – Calstis 2.10
Wavelength errors depend systematically on Y shift of echelle format
Echelle Wavelength Errors – Calstis 2.13
Lindler dispersion algorithm often reduces wavelength errors
Echelle Flux Calibration
ƒ Calstis 2.10 Methodology
ƒ
ƒ
ƒ
ƒ
Sensitivity curve for each grating, order, and CENWAVE
Sensitivity shifted by amount inferred from auto-wavecal
Relative precision goal: 5%
Limited by blaze function and scattered light
ƒ Effect of MSM Monthly Offsets
ƒ
ƒ
ƒ
ƒ
Preserve MAMA sensitivity throughout mission
Spectra shifted by a few pixels each month
Blaze function shift not the same as wavelength shift
Relative precision goal not always achieved
ƒ Achieving Calibration Goals
ƒ Old data: Calstis 2.13 includes Lindler blaze shift algorithm
ƒ New data: No offsets for echelles after Aug 4, 2002
ƒ ECF working on physical model of STIS
Echelle Blaze Shift Correction
Calstis 2.10
10% errors
Calstis 2.13
Disabling MSM Monthly Offsets for Echelles
ƒ MAMA Detector Lifetime
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
Quantum efficiency (QE) degrades as photons detected
Monthly offsets prevent localized sensitivity degradation
Monitored by Charles Proffitt and James Davies
Imaging and first order spectroscopy are main culprits
Maximum cumulative QE loss is <1% (typically 0.0001%)
Safe to disable MSM offsets for echelle modes
ƒ Implementation
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
Update MSM table in SCIOPSDB (Paul Goudfrooij, Jinger Mo)
Create dither ID “02” from “01”
Use December MSM positions (no offset) for all months
Preserve monthly offsets for first order MAMA modes
Update target X and Y locations for G140L and MIRFUV
New MSM table took effect on Aug 5, 2002
Update TRANS rules
MAMA Cumulative Images
FUV
NUV
Geocoronal Ly-α
First order
3” Above wire
Vignetting
First order
Echelle Line
3” Below wire
Bright
star
(Imaging)
Echelle order
Images clipped at 125,000 detected photons
Cumulative Decrease in Quantum Efficiency
QE loss is less than 1% for all pixels
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
New WFPC2 Documentation
1. Cycle 12 Instrument Handbook (V7.0, Biretta et al.)
Updated information on the CLOCKS=YES mode.
Status of anomalous rotational offset for WFPC2 filters.
Presentation of most up-to-date correction formula for CTE .
Discussion of latest conclusions on apparent “Long vs. Short”
anomaly.
Description of the new options available in the on-line ETC.
Description of latest flat-field files and improved accuracy.
A summary of the Cycle 11 calibration plan.
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
New WFPC2 Documentation
2. Data Analysis Tutorial (V3.0, Gonzaga et al.)
Written for novice WFPC2 users.
Being used as part of new DA training.
Major revisions include :
• overview on retrieving WFPC2 data from the archive
using StarView
• updated examples of useful WFPC2-related
IRAF/STSDAS tasks
• example of aperture photometry on NGC 2100 using
PHOT (including aperture correction, Dolphin’s CTE
correction, and conversion from WFPC2 flight to
standard magnitudes)
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
Charge Transfer Efficiency for Very Faint Objects and a
Reexamination of the Long-vs-Short Problem
Whitmore & Heyer WFPC2 ISR 2002-03
1. Whitmore, Heyer & Casertano (1999) formula does
reasonable job correcting for CTE loss down to
extremely low count levels.
2. Comparison between WHC99 and Dolphin (2000)
formula shows reasonable agreement, with D00 giving
better results.
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
CTE and Long-vs-Short : WFPC2 ISR 2002-03
Dolphin (2000)
Dolphin (2002)
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
CTE and Long-vs-Short : WFPC2 ISR 2002-03
3. Long-vs-short effect is very small (a few %) or nonexistent for uncrowded fields (<1000 stars/chip), but
for crowded fields (~10,000 stars/chip), apparent nonlinearities of tens of % are possible, most likely due to
an overestimate of the sky measurement in the short
exposure.
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
CROWDED FIELD
UNCROWDED FIELD
CTE and Long-vs-Short : WFPC2 ISR 2002-03
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
CTE and Long-vs-Short : WFPC2 ISR 2002-03
4. Preflashing is useful method of reducing effect of CTE
for some observations (i.e. bright objects on faint
background), but added noise and longer overheads
limit its effectiveness.
5. Detection thresholds for broad band observations
reduced by 0.1-0.2 mag in the ~7 years since WFPC2
was launched, with the worst-case (F336W) being ~ 0.4
mag.
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
New Contamination Rates (McMaster et al.)
F160BW, F170W, F218W, F255W, F336W, F439W
Comparison between
’97-’98 and ’01-’02
Slight increase in
clean count for UV
filters
Decrease of clean
count for F255W and
redwards
Slowing of rate for
filters up to F439W
F170W
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
New Contamination Rates (McMaster et al.)
F160BW, F170W, F218W, F255W, F336W, F439W
SM2 & SM3a
F170W
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
New Contamination Rates (McMaster et al.)
F160BW, F170W, F218W, F255W, F336W, F439W
F439W
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
Dither Working Group Report - MultiDrizzle & PyDrizzle
Automatic Registering, Cleaning & Combining of Dithered Images
(Koekemoer et al.)
MultiDrizzle is a single, integrated "wrapper" script which uses PyDrizzle, along
with other tasks in the dither package, to provide a single integrated approach to
cleaning and drizzling dithered images.
Carries out the following steps:
•Create bad-pixel masks
•Perform sky subtraction
•Optionally carry out single-image CR rejection
•Drizzle images onto separate output frames
•Create a median image from the drizzled images
•"Blot" the median back to the frame of each input image
•Compare the median and original to identify CR's
•Drizzle a final, combined image using the CR masks
WFPC2 UPDATE
TIPS : August 15, 2002 L.M. Lubin
Dither Working Group Report - MultiDrizzle & PyDrizzle
Refinement of Shifts :
Can refine shifts using catalogs (from Sextractor/DAO-Find)
Automatically creates new cosmic ray masks using improved shifts
Testing currently in progress :
CR rejection
Shift refinement
Median-image creation
Variety of WFPC2 & ACS datasets
STIS & NICMOS to be added next
Prototype version already currently available within Dither Working
Group; will be publicly released as soon as it is stabilized after
testing (approximately in the Fall).
MEMORANDUM
TO:
Distribution
DATE:
August 15, 2002
SUBJECT:
Questions and Answers from August 15, 2002 TIPS Meeting
SMOV3B Summary
Presenter – Carl Biagetti
Q: What is the number of external orbits predicted for SMOV3B? How does the actual number of external
orbits executed during SMOV3B compare to SMOV2?
A: SMOV3B was predicted to have about 380-390 external orbits. In actuality, 419 external orbits were
executed, which is much smaller than SMOV2 during which 780 external orbits were used.
Q: Should NICMOS be preparing for SMOV4 as well?
A: Yes, but at this point we do not know how NCS will be handled.
HST Metrics Website
Presenter – Ron Downes
Q: Is there any need to have Instrument Scientists and others to review the content of the website?
A: The content of the website has already been reviewed by the appropriate people, and we will contact
other individuals for input when needed.
Q: Has GSFC been briefed on the scope of this project? The website might be useful for them and can
potentially help the Institute with our reporting requirements? Have we solicited input from them?
A: The website was just recently released, and we will brief GSFC and solicit their input when the site
development has been completed more fully.
ACS Status
Presenter – Mark Clampin
Q: Regarding the 1% precision for the WFC flats calibration, is that pixel-to-pixel?
A: The estimates were based on analysis with stellar fields using L-flats. Formal error estimates gave a
pixel-to-pixel precision of much less than 1%. However, to account for systematic effects that are not fully
understood yet, a conservative estimate of 1% precision is being stated.
Q: At the upcoming calibration workshop, will we be presenting Pydrizzle for ACS?
A: Yes, we will have demos and posters for ACS Pydrizzle at the calibration workshop.
NICMOS Status
Presenter – Daniela Calzetti
Q: How different is the sensitivity between the values used for cycle 11 proposals and what we are seeing
right now?
1
A: The difference is about 10%.
Q: When did we execute the first GO science program after SM3B?
A: The first GO science program was executed on June 12th.
Q: Since OTFR has not yet been updated, how would that impact the GO programs?
A: All GO data will be impacted. We will need to provide updated reference files as soon as possible.
Q: Given the high linear dark current on the edges, should we be defining an aperture in the dithering
pattern to allow the avoidance of the edges?
A: We have been suggesting users to dither to the optimum aperture, and we will further considering the
suggestion of defining an aperture in the dithering pattern.
STIS Status
Presenter – Jeff Valenti
Q: Regarding the application of a global wavelength calibration solution over the entire chip to recover the
accuracy for the echelle wavelengths, would it be possible to apply individual separate solution to the
different order positions?
A: It is not possible because AUTOWAVECAL cannot generate the individual solution base on positions.
WFPC2 Status
Presenter – Lori Lubin
No questions.
2