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HST Focus & Optics Documentation:

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.
Niemi, S.-M., & Lallo, M. 02 Dec 2010 (pdf)

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. 01 Dec 2010 (pdf)

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. 01 Aug 2010 (pdf)

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 (pdf)

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

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 (pdf)

Temporal Optical Behavior of HST: Impact on Science Observations
R. B. Makidon et al., May 2006

Temporal Optical Behavior of HST: Focus, Coma & Astigmatism History
M. Lallo et al., May 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 (pdf)

HST Temporal Optical Behavior: Models & Measurements with ACS
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
As background information to support interpretation of results during testing under 2-gyro operation, this report summarizes typical behavior gleaned from several observations with ACS, WF/PC, WFPC2, STIS and NICMOS.
R. Gilliland 20 Feb 2005 (pdf)

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. Krist 01 Jun 2004 (pdf)

ACS field-dependent PSF variations...
Examines PSF width and ellipticity variations over WFC and HRC field resulting from optical and charge diffusion effects.
J. Krist 01 Jun 2003 (pdf)

OTA Focus Review Memo
Focus history, mirror moves, and typical accuracy are reviewed.
M. Lallo 25 Jun 2002 (pdf)

On-orbit alignment & imaging performance of HST ACS
G. F. Hartig et al. Jan 2002

HST Focus in Year 2000 - A Review of the Cycle 9 Focus Monitor Program
OTA-2001-01: After the last HST refocusing in June 2000,an enhanced OTA focus monitor(8829) began running as a cycle 9 observatory-level calibration to supplement...
M. Lallo 01 Feb 2001 (pdf)

Modelling HST Focal-Length Variations
Paper on the Modelling HST Focal-Length Variations.
J. Hershey 01 Jan 2000 (pdf)

Phase-retrieval analysis of pre- and post-repair HST images
J. Krist & C. Burrows, 1 Aug 1995

Focus Monitoring and Recommendation for Secondary Mirror Move
OTA-18: Focus monitoring and recommendation for secondary mirror move.
S. Casertano 01 Jan 1995 (pdf)