The bibliography below lists in reverse chronological order, the majority of related reports, papers, and presentations produced by STScI. These supplement other papers from the scientific community on observed HST PSF variations and resulting attempts at calibration.

NICMOS SM-2 SMOV Alignment Results
O. Lupie 01 Aug 1997

Transforming Non-COSTAR Aperture Positions to the New Vehicle Reference
M. Lallo 01 Sep 1996


Post-2003 Jitter File Description Document 
Defines the current format of the HST jitter file products. Supplement to the "Pre-2003 Jitter File Description Document" 
J. Baum 02 Feb 2003

Pre-2003 Jitter File Description Document 
Specifies the HST jitter files prior to spring 2003; describes their interpretation and application. For observations after this date, see "Post-2003 Jitter File Description Document" 
M. Lallo 24 Jun 2002

Instrument Science Reports

ISRs are technical reports written by members of the Observatory Group about various aspects of the instrument and data. They usually contain in-depth information about specific topics.

ISR TEL 2019: A Comprehensive Approach to HST Focal Plane Geometric Calibration
J. Sahlmann, E. Nelan, J. Averbukh, C. Cox, M. Lallo
06 Aug 2019

Velocity Aberration Correction for Parallel Observations
C. Cox 01 Oct 1997

An Investigation into the Guidance of FOC GTO 4073
S. Holfeltz 01 Jun 1994

A Determination of the Pointing History during FOS Scans of Mars
C. Cox 01 Dec 1993

Attitude Determination and Target Location
C. Cox 01 Nov 1992

Experience with the Hubble Space Telescope: 20 years of an archetype 
Optical Engineering paper describing the Hubble Mission, covering optical design and performance. Special emphasis is placed on the Space Telescope Science Institute's unique experience with Hubble's behavior as an astronomical telescope in the environment of low earth orbit for over two decades. 
M. Lallo, Jan 2012

ISR 2012-01: COS FUV Focus Determination for the G140L Grating
Describes the procedures for determining the COS FUV fine-focus for the G140L grating.
P. Ghavamian 03 Oct 2012

ISR 2012-14: Breathing, Position Drift, and PSF Variations on the UVIS Detector
L. Dressel 13 Jul 2012

Keeping the Hubble Space Telescope in Focus 
SPIE paper describing the focus model details and development.
C. Cox & M. Lallo, 1 Jun 2012

20 years of Hubble Space Telescope optical modeling using Tiny Tim 
SPIE paper describing the evolution and applications of the Tiny Tim PSF Simulation software package.
J. E. Krist & R. N. Hook, 1 Oct 2011

ISR-WFC3-2011-07, High Contrast Imaging using WFC3/IR 
Presents results of performing both classical and LOCI (Locally Optimized Combination of Images) PSF subtractions on WFC3/IR images of a bright (V=6.9) star with simulated companions. 
A. Rajan et al., 10 Feb 2011

ISR-TEL-2011-01, Evaluation of the HST Focus Model 
Describes the performance of the current focus model which includes a new secular formula and updates to SI-specific offsets.
C. Cox & S.-M. Niemi, 23 Feb 2011

ISR-TEL-2010-03, Phase Retrieval to Monitor HST Focus: II. Results Post-Servicing Mission 4 
Discusses the results of focus monitoring since the last HST Secondary Mirror adjustment in July 2009, after Servicing Mission 4. Examines current focus of ACS & WFC3. 
S.-M. Niemi & M. Lallo, 2 Dec 2010

ISR-TEL-2010-02, HST Focus in SMOV4: Strategy for OTA adjustment & SI Focus 
Describes the observatory-level effort to produce optimal focus during Servicing Mission Observatory Verification 4.
M. Lallo et al., 1 Dec 2010

ISR-TEL-2010-01, Phase Retrieval to Monitor HST Focus: 1. WFC3 UVIS Software Implementation 
Describes the adaptation and calibration of HST phase retrieval code to WFC3, and its subsequent use for focus and image monitoring.
S.-M. Niemi et al., 1 Aug 2010

ISR-WFC3-2009-45, WFC3 SMOV Programs 11424, 11434: UVIS Channel On-orbit Alignment 
Describes the setting of the UVIS channel corrector mechanisms for optimal image quality and confocality with the other SIs.
G.F. Hartig et al., 14 Dec 2009

ISR-WFC3-2009-46, WFC3 SMOV Programs 11425, 11435: IR Channel On-orbit Alignment 
Describes the setting of the IR channel corrector mechanisms for optimal image quality and confocality with the other SIs.
G.F. Hartig et al., 14 Dec 2009

ISR-WFC3-2009-38, WFC3 SMOV Programs 11436/8: UVIS On-orbit PSF Evaluation 
Assessment of image quality in the WFC3 UVIS channel on orbit, following its optical alignment to the HST OTA.
G.F. Hartig, 10 Nov 2009

ISR-WFC3-2009-37, WFC3 SMOV Programs 11437/9: IR On-orbit PSF Evaluation 
Assessment of image quality in the WFC3 IR channel on orbit, following its optical alignment to the HST OTA.
G.F. Hartig, 10 Nov 2009

ISR-WFC3-2008-41, WFC3 IR PSF Evaluation in Thermal-Vacuum Test #3 
Assessment of image quality of the WFC3 IR channel in a flight-like thermal-vacuum environment.
G.F. Hartig, 16 Sep 2008

ISR-WFC3-2008-40, WFC3 UVIS PSF Evaluation in Thermal-Vacuum Test #3 
Assessment of image quality in the WFC3 UVIS channel in a flight-like thermal-vacuum environment.
G.F. Hartig, 20 Aug 2008

ISR-WFC3-2008-014, WFC3 Support in Tiny Tim 
Discusses the extension of the PSF simulator, Tiny Tim, to model WFC3 PSFs.
R. Hook & F. Stoehr, 27 Jun 2008

ISR-ACS-2008-03, HST Focus Variations with Temperature 
Describes the temperature-based HST focus model that is the basis of our current (post-2002) modeling tool.
D. Di Nino et al., 7 May 2008

HST Focus & PSF Stability 
Telescopes Group Talk Series, Talk #1 
M. Lallo, 19 Sep 2007

ISR-ACS-2007-12, ACS PSF Variations with Temperatures 
Describes observed PSF widths and their correlation with HST temperatures. Predates the temperature-based focus model detailed in Di Nino et al., (2008).
K. C. Sahu et al., 18 Sep 2007

ISR-TEL-2006-01, Modeling Aberrations in the Advanced Camera for Surveys 
Investigates the plausibility of optical misalignments as the cause of apparent aberration changes implied by phase retrieval of HRC PSFs. 
K. Houairi et al., 13 Oct 2006

Temporal Optical Behavior of HST: Impact on Science Observations 
SPIE paper giving some discussion and examples that relate measurements of defocus wavefront error to characterizations more common to science data analysis (e.g. FWHM, and ellipticity).
R. B. Makidon et al., May 2006

Temporal Optical Behavior of HST: Focus, Coma & Astigmatism History 
SPIE paper describing variations of HST aberrations as revealed by ongoing monitoring using phase retrieval techniques.
M. Lallo et al., May 2006

ISR-ACS-2006-01, PSFs, Photometry, and Astrometry for the ACS/WFC 
Develops and provides a method for characterizing the HST PSF using the "effective PSF". A given observed ACS WFC PSF can be fit by interpolating between an array of fiducial PSFs over the detector, and by employing a "perturbation PSF" to capture the time-variability due mainly to focus changes. Effective PSF grids for 6 common WFC filters are provided, along with FORTRAN code for performing this analysis.
J. Anderson & I. R. King., Feb 2006

ISR-TEL-2005-03, HST Temporal Optical Behavior & Current Focus Status 
Reviews the timescales, mechanisms, and importance of variations in aberrations (focus, coma, astigmatism). Presents focus status of the observatory.
M. Lallo et al., 27 Oct 2005

HST Temporal Optical Behavior: Models & Measurements with ACS 
HST Calibration Workshop presentation describing apparent behavior of coma, astigmatism, and focus in ACS/HRC, and their effects on measured PSF characteristics.
R. B. Makidon et al., 30 Oct 2005

ISR-TEL-2005-02, Guiding Errors in 3-Gyro: Experience from WF/PC, WFPC2, STIS, NICMOS and ACS 
This report summarizes typical behavior gleaned from several observations with ACS, WF/PC, WFPC2, STIS and NICMOS.
R. L. Gilliland, 20 Feb 2005

Telescope Image Modeling (Tiny Tim) Handbook 
User's manual for "Tiny Tim". Software package for simulating HST PSFs. NOTE: this is the general User's Guide. It pre-dates WFC3 capability and the web-based user-input defocus values.
J. E. Krist, 1 Jun 2004

ISR-ACS-2003-06, ACS field-dependent PSF variations
Examines PSF width and ellipticity variations over WFC and HRC field resulting from optical and charge diffusion effects.
J. E. Krist, 1 Jun 2003

OTA Focus Review Memo 
Reviews focus history, mirror moves, and typical accuracies of measurements and commands.
M. Lallo, 25 Jun 2002

On-orbit alignment & imaging performance of HST ACS 
SPIE paper documenting the on-orbit optical alignment of the ACS, with an assessment of residual aberrations and comparisons with models. Effects of HST OTA focus changes are also discussed.
G. F. Hartig et al., Jan 2002

ISR-OTA-2001-01, HST Focus in Year 2000 - A Review of the Cycle 9 Focus Monitor Program 
Discusses the state of HST focus during the science cycle following an HST refocusing in June 2000.
M. Lallo, 1 Feb 2001

SESD-97-01, Modelling HST Focal-Length Variations 
This report laid out the first attempt at a comprehensive temperature-based HST focus model. Though the specific model has since been replaced (Di Nino et al., 2008, & Cox 2011), the temperatures and temperature functions that most closely correlate with focus changes were first identified here. Also described was an attempt at a predictive model, expressing the focus function in terms of HST attitude parameters, rather than the resulting temperature changes. 
J. Hershey, Jun 1998

ISR-WFPC2-1997-10, WFPC2 Photometry from Subtraction of Observed PSFs 
Based on observed PSFs from WFPC2 calibration programs, a series of PSF subtraction tests were performed and the resulting photometry analyzed.
J. Surdej et al., 3 Oct 1997 (postscript)

WFPC2 Photometry from Subtraction of TinyTim PSFs 
Describes a method for determining best fitting model PSFs for WFPC2/PC1 observations.
M. Rémy et al., Sept 1997 (postscript)

ISR-WFPC2-1997-01, Impact of Focus Drift on Aperture Photometry 
Examines the impact of long term and short term focus variations on small aperture photometry performed on WF & PC channels of WFPC2.
A. Suchkov & S. Casertano, 31 Jan 1997

Phase-retrieval analysis of pre- and post-repair HST images 
Applied Optics paper discussing phase retrieval techniques used for HST PSF monitoring and characterization.
J. E. Krist & C. J. Burrows, 1 Aug 1995

ISR-OTA-18, Focus Monitoring and Recommendation for Secondary Mirror Move 
Focus monitoring and recommendation for secondary mirror move.
S. Casertano, 1 Jan 1995

SESD-1993-16, Orbital Focus Variations in the Hubble Space Telescope 
This report first described the relationship between observed HST orbital focus changes and temperatures differences measured at HST's Light Shield just fore of the Secondary Mirror.
P. Y. Bély et al., Aug 1993

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