TIPS-JIM Meeting
15 January 2004, 10am, Auditorium
1.
MultiDrizzle Status and Development
Overview
Anton Koekemoer
2.
Summary of the JWST Mission and
Jerry Kriss
Observatory System Requirements Reviews
3.
WFC3 Calibration Activities at GSFC
John MacKenty
Next TIPS Meeting will be held on 19 February 2004.
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
MultiDrizzle Status and Development Overview
Anton Koekemoer, ACS+WFPC2 Branch
Project Overview
– Forum: Dither Working Group
– Software Development Mechanism
– Development Timeline to Date
MultiDrizzle Requirements
– General
– Instrument-Specific Considerations
MultiDrizzle Testing
– General Overview
– Instrument-Specific Considerations
Priorities and Timescales
– Development and Testing
– Documentation
– Community Feedback
Roadmap for Future Development
1
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
MultiDrizzle Project Overview
Forum - Dither Working Group (established January 2002):
– Purpose:
Coordinate development & implementation of fully integrated software
to automatically register, CR clean and combine dithered HST images
(software intended as successor to CL-based STSDAS “dither” pkg)
– Process:
Provide forum for dialog between INS, SSB, and dither software users
Define requirements and set priorities for development and testing
Determine roadmap for implementation, distribution, documentation
– Membership:
Representatives from INS, SSB, + others attending as needed
Development Mechanism:
– MultiDrizzle requirements initially developed through discussions
within Dither Working Group and interations with users
– MultiDrizzle prototype (Koekemoer, Fruchter, Hook et al.) developed
to demonstrate desired functionality; beta release under STSDAS
– SSB redesigns the code, reproducing the functionality of prototype
– Continual testing by SSB and INS, and dialog with external users
2
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
MultiDrizzle Project Organization
3
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
MultiDrizzle Development to Date
Jan - May 2002:
– Definition of MultiDrizzle requirements in Dither Working Group
– Initial prototype MultiDrizzle (Koekemoer, Fruchter, Hook et al.)
Jun - Sep 2002:
– Distribute prototype to variety of GOs: GOODS, GEMS, High-Z SNe,
GRBs, APPLES, Helix Nebula; external GOs at GSFC, CfA, Caltech,...
Oct - Dec 2002:
– Announce general availability to GOs on beta-test basis (Cal Wkshp)
– Initial suite of ACS, WFPC2 test datasets
Jan - Jun 2003:
– Hand over prototype to SSB for inclusion in STSDAS (Hack et al.)
– More user feedback, improve robustness, refine testing
Jul 2003 to present:
– SSB redesign of MultiDrizzle code (Hack, Hanley et al.) using
prototype MultiDrizzle as a basis for defining functionality
– Develop formal regression test suites
4
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
MultiDrizzle Requirements - General
Fundamental Requirements:
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Combine arbitrary collections of images (including single-group)
Automatically calculate required output image size
Determine shifts from headers
[Optionally refine shifts or allow input delta-shifts]
Carry out sky subtraction on input images
Automatically perform CR rejection:
Drizzle input exposures onto separate, registered output images
Create a clean “median” image
Blot the clean image back to frame of each individual exposure
Run deriv, driz_cr to create cosmic ray masks
Use CR masks in final drizzle combination
– Allow external bad-pixel masks to be imported
– Allow individual steps to be selected when running
Overall philosophy:
– Allow user freedom in specifying behavior via parameters
– Defaults must enable good results from “one-touch” operation
5
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
Requirements – Instrument-Specific
ACS
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WFPC2
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Accurately handle WFC, HRC, SBC imaging data
Single-group images (eg only [sci,1])
Sub-array data
Include new geometric distortion-residual images (Anderson)
Handle 4-group WFPC2 GEIS as well as FITS format files
Single-group images (eg WF3 only)
Sub-array data
Include updated geometric distortion (Platais et al)
NICMOS
– NIC1, NIC2 or NIC3 imaging
– Ability to handle multi-accum datasets
STIS
– CCD as well as FUV, NUV-MAMA datasets
– Imaging (initially) as well as 2d spectroscopy data (later)
6
STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
MultiDrizzle Testing- General Overview
Basic Functionality:
– Do new versions run successfully for small subset of test datasets?
Extended functionality:
– Do new versions work for the full range of datasets?
Functionality tests can be automated by regression:
– Run automatically on a periodic basis
– Comparison performed automatically with reference test images,
and results reported in summary form
Scientific integrity:
– Do functional versions deliver scientifically valid results?
– Different target types:
Sparse extra-galactic fields, crowded stellar fields
Large extended objects or diffuse emission across entire field
Scientific tests require additional analysis, eg:
– PSF measurements of stars to ensure shifts, etc are correct
– x,y position comparisons to verify correct astrometry
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STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
Testing – ACS + WFPC2
ACS WFC, HRC, + WFPC2:
– Basic datasets:
2-point line dither
4-point box dither (single-visit)
– More advanced datasets:
Single-visit, small offsets, higher number of dithers
Single-visit, large offsets (comparable to chip size)
Multi-visit, small + large offsets
– Number of images:
Small datasets (2-3 exposures total)
Medium datasets (4-6 exposures total)
Large datasets
ACS testing lead: Shireen Gonzaga
WFPC2 testing lead: Vera Platais
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STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
Testing (cont’d) - NICMOS, STIS
NICMOS:
Imaging - NIC1, NIC2, NIC3:
– Multi-accum datasets
– Different dither patterns (spiral)
– Large-scale + small-scale dithers to account for chip defects
NICMOS testing lead: Megan Sosey
STIS CCD + MAMAs:
Imaging:
– Mostly large-scale dithering
Spectroscopy:
– Dithering along slit
– Dithering along spectral direction
– CTE: CRs, bad pixels are a major issue (since low background)
STIS testing lead: Linda Dressel
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STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
Priorities and Timescales
Development and Testing:
Near-term (+ 1 month):
– INS: Identify test datasets and create baseline results
– SSB: Include tests in regression mechanisms
– SSB: upgrade current beta-release MultiDrizzle to fully supported
Long-term:
– Maintain database of reference results
– Update test database when warranted by code changes
– SSB release redesigned MultiDrizzle: for users and HST pipeline
Documentation:
– Release TIR describing development plans for MultiDrizzle
– Release updated Dither Handbook V3.0 to user community, with full
description of the use of MultiDrizzle
Community Feedback:
– Continue to collect suggestions and feedback from users
– Incorporate into regular prioritization planning
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STScI TIPS, 15 January 2004
MultiDrizzle Overview - Anton Koekemoer
Proposed Roadmap for Future Development
Mar 2004:
– SSB to upgrade original “prototype” MultiDrizzle to a fully supported
version (eg via patch release, and/or from STSDAS website)
– INS to release updated Dither Handbook V3.0 with full description
of the use of MultiDrizzle software
Jan - Jun 2004:
– INS provide test datasets to SSB (near-term), update as necessary
– SSB to complete the redesigned MultiDrizzle as user software
– SSB to release redesigned MultiDrizzle in Summer 2004 STSDAS
Jul - Sep 2004:
– SSB, INS work on more robust, streamlined MultiDrizzle for fully
automated use in HST Pipeline Operations
– Continue to incorporate feedback and usage patterns from GOs
Oct 2004 onwards:
– Continuing algorithmic development to improve software, eg:
tweakshift (automated catalog-based shift refinement)
more robust CR rejection techniques for few-exposure datasets
11
Summary of the JWST Mission and Observatory
Systems Requirements Reviews,
and
Micro-Shutter Array (MSA) Confirmation Review
Jerry Kriss
01/15/2004
TIPS/JIM
SRR Objectives
Confirm that mission-level and observatory
requirements meet the project objectives
Confirm observatory-level specifications are
sufficient to meet the project objectives
Validate that the mission architecture concept
can support the functional, operational,
interface and performance requirements
Show that the requirements have been flowed
down and are understood at the next level.
01/15/2004
TIPS/JIM
SRR Review Team
Dennis Dillman, Chair
Steve Graham
Alain Berinstain
Ted Harper
Jacques Louet
Colin Jones
Steve Scott
Alexander Krimchansky
Gene Waluschka
Sachi Babu
Tom McCarthy
Mark Fontaine
Joe Schepis
Peiman Maghami
Minh Phan
Dr. Mal Niedner
01/15/2004
GSFC System Review Office
GSFC Project Management
CSA
CSA
ESA
ESA
GSFC Chief Engineer
GSFC
GSFC Optics
GSFC Detectors
GSFC Thermal
GSFC
GSFC Electromechanical
GSFC
GSFC
GSFC Space Sciences
TIPS/JIM
JWST Requirements Tree
JWST Program Plan
JWST-PLAN-000633 L1
Program
Baselined
In CM Review
Drafts Available
Allocation Documents
System
FGS SRD
JWST Science
Requirements Document
JWST-RQMT-002558SR
NIRCam SRD
NIRSpec SRD
JWST Mission
Requirements
JWST-RQMT-000634 MR
JWST Performance
Assurance Requirements
JWST-RQMT-000650 PA
JWST Mission Operations
Concept Document
JWST-OPS-002018 MOC
FGS OCD
MIRI SRD
Budgets
WFE Rev Q 03-JWST-0405
Efficiency
Pointing
WFS&C Requirements
Allocation Document
JWST-RQMT-002017 WFS
NIRCam OCD
EMC Control Plan
JWST-PLAN-002449
NIRSpec OCD
EMC
Performance Quality
Assurance Plan
JWST-PLAN-002412
Contamination Control
Plan
JWST-PLAN-002028
CCP
PQ
MIRI OCD
Segment
Flight Observatory to
Ground Segment IRD
JWST-IRD-000696 FG
Ground Segment
Requirements
JWST-RQMT-001056
GS
JWST Observatory
Specification
JWST-SPEC-002020
RD
Launch Segment
Specification
JWST-SPEC-001999
OL
OBS
JWST-ICD-001998 FGC
Radiation Requirements
Allocation Specification
JWST-SPEC-000871
Observatory to Launch
Segment IRD
JWST-IRD-002000
JWST System
Verification Plan
JWST-PLAN-002027
LS
JWST-ICD-002001
OLC
Environmental Req’s
for the JWST Observatory
JWST-SPEC-003149 EV
Observatory I&T Plan
JWST-PLAN-002030
Observatory to
GSE IRD
D36127 OG
D36128 OGC
Fault Protection
Requirements Document
JWST-RQMT-002450
FP
Element
ISIM Requirements
Document
JWST-RQMT-000835
ISIM
ISIM to OTE and
Spacecraft IRD
JWST-IRD-000640
ISIM to OTE and IOS-IR
JWST-ICD-001831
01/15/2004
SC Requirements Document
JWST-RQMT-002039
SC
IOSC
TIPS/JIM
Spacecraft to OTE
ICD
D35231 SOIC
OTE Specification
JWST-RQMT-002021
OTE
JWST Science Requirements
(John Mather presenting)
Four themes:
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First Light
Assembly of Galaxies
Birth of Star and Planetary Systems
Planetary Systems and the Origins of Life
Level 1 Mission Success Criteria:
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Density of galaxies
Spectra of galaxies
Physical and Chemical properties of young stellar objects
Observing time---5 yr mission, 1.1e9 s on target
Telescope > 25 m2
Strehl ratio > 0.8 at 2 µm
Encircled energy > 0.74 within 0.15 arc sec at 1 µm, stable for > 24 hrs.
Thermal environment zodi limited 0.6 -- 10 µm
Example of how Level 1 requirements flow down: 1st-light objects are rare
(<1 arcmin-2) ==> large, unvignetted FOV with low distortion.
01/15/2004
TIPS/JIM
Requirement Changes Since
the Delta-MDR
Redesigned sun shield---smaller, better
clearances, simpler deployment – but, it could
make mission planning more difficult.
Upgrade the power system to accommodate
ISIM power needs.
01/15/2004
TIPS/JIM
Requirements Still in Work
Moving targets. Quantitative requirements are TBD,
depending on cost.
Sensitivity. New numbers developed, but CCB on hold
pending NGST replan contract change.
Mass allocations are TBD pending resolution of the ISIM
Electronics Compartment (IEC) study.
Ariane 5 change not yet flowed down (no expected impact).
FOV offsets not yet flowed done (no expected impact).
Reliability. Recent MRD change says goal is 92% for
Spacecraft+OTE. Goal for whole observatory is pending.
OTE to ISIM structural interface definition.
X vs. Ka-band study. [Should finish soon in favor of Ka.]
01/15/2004
TIPS/JIM
Key Issues
Concept for locating ISIM electronics in Region 2 is not viable.
• FPEs must be within 6m of focal planes, in Region 2
• Adding ICE boxes advantageous
• "Saddle-bag" configuration won't work. (Too massive; thermal
problems.) Further work underway. (IEC trade study. Will take FPE
rqmnts into account.)
Mass Allocations
• Current mass reserves are at 21%. Would like to be at 25%. Biggest
problem areas are the IEC accommodation, and the sun shield
containment system.
• Spacecraft is 250 kg over its allocation
• OTE is 405 kg over its allocation
• MIRI dewar is 20 kg over its allocation; NIRCam is 7 kg too heavy.
01/15/2004
TIPS/JIM
(ISIM Region 1)
(ISIM Region 2)
(ISIM Region 3)
01/15/2004
TIPS/JIM
SRR Summary Results
The board thought that the review was excellent.
~60 Requests for Action (RFAs) generated.
Major issues in the RFAs:
• Request for an Observatory-level TV test.
• Request for deployment tests in TV.
• Desire to make several of the Mission/Obs rqmnts less
vague and more verifiable (e.g., those related to eventdrive ops).
• Need to do a better flow down of the efficiency rqmnt and
tie it in to data quality and reliability in a more
comprehensive way.
• Fault handling requires more development.
01/15/2004
TIPS/JIM
Micro-Shutter Array (MSA)
Confirmation Review
Held 12/18/03 at GSFC to assess whether the MEMS microshutter array should be the slit-defining mechanism for
NIRSpec.
Successes:
• Fabricated 128 x 64 arrays (flight will be 384 x 175)
• Demonstrated 2-D addressing
• Implemented light shields
• Performed cryogenic life tests
• Measured pixel failure rate at end-of-life
• Measured open/closed shutter contrast ratio [2,00010,000 warm; ~200 cold (due to shutter curvature)]
• Performed an acoustic test
01/15/2004
TIPS/JIM
100 µm
20 µm
01/15/2004
Magnetic Stripes on MSA Frontside
MSA Light Shields
100 µm
TIPS/JIM
MSA Backside
Micro-Shutter Array (MSA)
Confirmation Review
Concerns:
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Yield is still low
Light shields frequently break off
Shutters curve and bend when cooled
Life testing does not meet <10% of rows with a failedopen shutter
• Crude acoustic/shake tests increase rate of failed-opens
Further development needed, but optimism prevails.
The MSA remains the preferred approach, and the European
selection is proceeding on this basis.
01/15/2004
TIPS/JIM
WFC3 TIPS Presentation
January 15, 2004
Optical
Stimulus
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
1
Highlights
• Major Milestone: first system level testing
– STScI lead instrument calibration run (ambient testing)
– UVIS channel with flight detector
– Successfully validated:
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Image quality and throughput of UVIS channel (1st look at UV)
Instrument operation with full flight electronics and SITS system
STScI pipeline(s) and ability to work with data volume
WFC3 ambient test environment (CASTLE system and warm det)
WFC3 ICAL team preparedness (proposals/SMS/staffing)
– Testing found two significant anomalies (filter ghosts and Xtalk)
• Program schedule has slipped several months
– Optical alignment issue with detector packages (now resolved)
– Need for expanded science testing
• WFC3 Science Oversight Committee @ STScI 5-6 Feb
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
2
Optics Testing and TEC Power
• Optics testing found significant mis-alignment of flight
CCD package
– No harm/risk to detector focal plane (external mounting ring)
– Cause traced to Ball Aerospace alignment step (details still under
investigation but understood sufficiently to proceed)
– Has resulted in hold on UVIS Flight Spare and IR Flight packages
– Much credit to George Hartig and Sylvia Baggett
• Anomalous behavior of CCD TEC controller during
cooldown observed during optics testing
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Jan 15, 2004
Problem tracked by GSFC electronics team to LVPS component
Ball substituted hollow core transformer
Fix in process (3-4 months for parts fab/test)
Operational workaround in place for ambient testing (no impact)
WFC3 TIPS – John W. MacKenty
3
Test Environment
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CASTLE system working well
– Flats and point sources
– Interleaved with SMS running
on the SITS system
– Driven by STScI scientist
generated proposals
– ICAL team working very well
together
– Kudo’s to Neill Reid, Ray
Kutina and the rest of the
ICAL team
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
4
Flat Fields and Point Sources
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F814W Flat field shows good
performance with low level
flare in corner (not a problem)
Point sources can show oval
ghosts from chip to window
reflections (modeled previously
and within expectations).
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
5
System Throughput (Preliminary)
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System throughput tested with a
set of wide and medium filters
Meets expectations
– Validates SI component level
measurements
– First test of UV image quality
and throughput
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
6
Air-gap Filter Ghosts
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Ghost intensity is a function of
wavelength
– Most pronounced at edges of
bandpass
– Present at both blue and red
sides of bandpass
– Initial attempts to sum flux
have not yet succeeded
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Jan 15, 2004
Images at left show F225W
with 4nm input at 10nm steps
on red side of the passband
WFC3 TIPS – John W. MacKenty
7
Air-gap Ghosts (2)
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Ghosts are worst in F218W and
F225W
F225W
– Far exceed 0.2% CEI Spec
– Can contain 30+% of total flux
for very red sources
– Morphology is highly position
dependent within field
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Team working with Barr
Associates and JPL to
– Model cause
– Duplicate behavior with spares
in optical test setup at GSFC
– Fabricate alternate filters
F218W
• Single substrate now possible
• Change gap or use two filter
slots to realized these 2 filters
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
8
F606W Artifact
F606W
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Unexplained compact ghosts in
F606W
White light features few 0.1%
Monochromatic light
– Very faint in band center
– 10% at edges of band
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F814W
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Jan 15, 2004
Not seen in F625W, F814W
Filter manufactured by Omega
on single substrate (different
technology than UV filters)
Scan of all filters underway that
should complete next Tuesday
or Wednesday
WFC3 TIPS – John W. MacKenty
9
CCD Electronics Cross-talk
• Image in one quadrant of the UVIS field of view can create
features in the other three quadrants.
– Seen in ACS (but WFC3 effect is few times more pronounced)
– Can suppress features in other chip using slower timing pattern
• Isolates source to limited part of signal chain
Jan 15, 2004
WFC3 TIPS – John W. MacKenty
10
Hardware Flow
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Jan 15, 2004
UVIS Flight Detector package realigned at Ball this month
Mini-ambient calibration (validates
realignment and established SOFA
position)
SOFA removal to fix electronics
redundancy issue – filter swap??
Full ambient test of UVIS channel
(CSM removed to replace
motor/resolver set)
IR detector delivery and noise tests in
ambient
System level thermal vacuum testing
(first calibration of IR channel)
WFC3 TIPS – John W. MacKenty
11