"8 f_/_ ]_5_ cR-189365 L f . INSI1TLJTE loop Hubble Space Telescope Faint Object Camera Instrument Handbook [Post-COSTAR] (NASA-CR-189365) HUBBLE SPACE N94-36795 TELESCOPE FAINT OBJECT CAMERA INSTRUMENT HANDBOOK (POST-COSTAR), VERSION 5.0 (Space Telescope Unclas Science Inst.) 104 p G3/89 0014038 .... 7 = _............... :___i .................... Version 5.0 -: May 1994 Revision History Handbook Version 1.0 May 1985; edited by F. Paresce Handbook Version 2.0 April 1990; edited by F. Paresce Handbook Version 3.0 April 1992; edited by F. Paresce Handbook Version 4.0 February 1993; edited by A. Nota, R. Jedrzejewski, W. Hack Handbook Version 5.0 May 1994; edited by A. Nota, R. Jedrzejewski, W. Hack ,,j The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., for the National Aeronautics and Space Administration. i . REPORT DOCUMENTATION PAG OMB or ANo. provo0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathartng and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Mana_lement and Budget, Paperwork,Reduction Proiect I0704-0188), Washin_lton, DC 20503. 1. AGENCY USE ONLY (Leaveblank) 2. REPORTDATE 3. REPORTTYPE AND DATESCOVERED May 1994 Contractor Report 14. TITLE AND SUBTITLE 5. FUNDING NUMBERS Rubble Space Telescope Faint Object Camera Instrument Handbook (v. 5.0) [Post-COSTAR] 6. AUTHOR(S) 633 Editors: A. Nota, R. Jedrzejewski, P. Greenfield and W. Hack 7. PERFORMINGORGANIZATIONNAME(S)ANDADDRESS(ES) 8. PERFOR_NGORGAN1ZATION REPORTNUMBER Space Telescope Science Institute 3700 San Martin Drive Baltimore, MD 21218 9o SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITO_NG AGENCYREPORTNUMBER National Aeronautics and Space Administration Washington, D.C. 20546-0001 CR-189365 11. SUPPLEMENTARY NOTES Technical Monitor: R. Dilling, Code 633 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTIONCODE Unclassified-Unlimited Subject Category 82 Report is available from the NASA Center for AeroSpace Information, 800 Elkridgc Landing Road, Linthicum Heights, MD 21090; (301) 621-0390. 13. ABSTRACT(Maximum200words) The Faint Object Camera (FOC) is a long-focal-ratio, photon-counting device capable of taking high-resolution two-dimensional images of the sky up to 14 by 14 arcseconds squared in size with pixel dimensions as small as 0.014 by 0.014 arcseconds squared in the 1150 to 6500 ._ wavelength range. Its performance approaches that of an ideal imaging system at low light levels. The FOC is the only instrument on board the Hubble Space Telescope (HST) to fully use the spatial resolution capabilities of the Optical Telescope Assembly (OTA) and is one of the European Space Agency's contributions to the HST program. 14. SUBJECT TERMS 15. NUMBEROF PAGES Hubble Space Telescope 96 16. PRICE CODE 17. SECURITYCLASSIFICATION 18. SECURITYCLASSIFICATION 19. SECURITYCLASSIFICATION 20. LIMITATIONOF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT \ Unclassified Unclassified Unclassified Unlimited NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) \ Prescribed by ANSI Std. 239-t8, 298-102 FAINT OBJECT CAMERA INSTRUMENT HANDBOOK [Post-COSTAR] A. Nota R. Jedrzejewski P. Greenfield W. Hack Space Telescope Science Institute 3700 San Martin Baltimore, MD 21218 Version 5.0 May 1994 FOC Instrument Handbook Version 5.0 i CAUTION The procedures for creating a Phase II proposal are being reviewed and revised as this is written. We strongly recommend that users check the Phase II docu- mentation carefully. We also recommend checking on STEIS at that time for a revised version of this Instrument Handbook. Major changes from the FOC Instrument Handbook,version (4.0) 1. The F/48 Camera is not available in Cycle 5, due to the high background count rate and high-voltage turn-on problems which have occurred in the past two years. The F/48 was last successfully switched on December 22, 1993, before the deployment of the COSTAR corrective optics. The camera remained on for the duration of the observation. While the acquisition image showed a background level which, although high, was consistent with the previous dark count images, a preliminary analysis of the following images showed immedi- ately that the background increased dramatically with time, eventually reaching saturation levels approximately two hours after HV switch-on. Whether this characteristic of increasing background is a permanent condition of the F/48 is not clear. As a consequence, the F/48 will not be made available to GOs during Cycle 5, pending further testing and analysis. See section 6.4 for further details. 2. The Point Spread Function description has been updated to reflect the results from SMOV and early Cycle 4 calibrations. COSTAR has restored much of the OTA capability, in that the COSTAR-corrected PSF contains more than 75% of the light within a radius of 0.1 arcsecond at visible wavelengths while only losing less than 20% of the light to the two reflections at the two extra mirror surfaces. The net increase in sensitivity is a factor of approximately 3--4 at visible wavelengths. Section 6.1 contains all the new information. 3. The Absolute Detector Quantum Efficiency has been updated after execution of the related Cycle 4 Calibration program. A new OTA + COSTAR + FOC central absolute quantum efficiency curve is provided as a function of wavelength for the four FOC imaging and spectrographic configurations. The data represent the product of in-orbit measurements for the new F/96 relay+OTA absolute quantum efficiency, and ground-based reflectance calibrations of the COSTAR mirrors for the new F/48. The predicted loss of light from two reflections of MgF2 coated aluminum COSTAR mirrors amounts to a 20% loss in the visible and a 35% loss in the ultraviolet. The loss due to the COSTAR mirrors is more than compensated by the improvement in image quality, since the encircled energy performance is improved from 18% within a 0.1" radius to -_80% within the same area, based on theoretical PSFs. For a detailed discussion, see Section 6.3. In addition, a format dependence sensitivity effect has been studied, and the results are provided in Section 6.3.1 4. The Format-Dependent Sensitivity Effect has been measured and has been found to be substantial (as much as a 45% change). Section 6.3.1 lists the relative sensitivities of the more common imaging formats. 5. The Geometric Distortion discussion has been updated (Section 6.11) and new values for the FOC plate scale are provided in Section 6.12). 6. The prescription for Estimating Exposure Times has been updated to take into ac- count the new PSF and DQE parameters (see Section 7.0). FOG Instrument Handbook Version $.0 ii CONTENTS 1.0 INTRODUCTION 2.0 COSTAR OVERVIEW 6 3.0 INSTRUMENT OVERVIEW 4.0 DETAILED INSTRUMENT DESCRIPTION 12 4.1 Transfer Optics .................................. "................12 4.2 Focal Plane Apertures ........................................................1914 4.3 InternalCalibration System ....................................... iiii:i:iiii 21 4.4 Filter Wheels ............................................ 21 4.4.1 Ba.ndpass and Neutral Density Filters .................. 29 4.4.2 Objective Prisms ....................................................... 30 4.4.3 Polarizers ....................................... 34 4.5 Long Slit Spectrographic Facility ........................................... "" 37 4.6 Detectors ..................................... 4.6.1 Image Intensifier and Coupling Lens .................................... 37 ............................ 38 4.6.2 TV Tube . _................................. .................... 38 4.7 Video Processing Unit ................................... ............. 39 4.8 Science Data Store ............................................. 41 5.0 OBSERVING ARRANGEMENTS 5.1 Imaging, Occultation and Spectrographic Modes .............................. 41 5.2 Target Acquisit_0n Modes ' .... 44 5.2.1 Mode I Target Acquisition - INTeractive ACquisition ................... 44 5.2.2 Mode III T_sgettioAnCqUisi ti°n- Blind Pointing ............................ 4_ 5.2.3 Early ACQ " " " •.................................................... 146 5.3 The FOC Target Acquisition Apertures ....................................... 47 6.0 INSTRUMENT PERFORMANCE 47 .,.,°,.,l.,o.l., 6.1 The Point Spread Function (PSF) ............................. 50 6.1.1 Image Quality and Field Dependence of the PSF ......................... 51 , o,. 6.2 Dynamic Range .......... • ...................................... .. 51 6.2.1 Uniform Illumination .................................................. 52 ...e.°,.. Io,°..,°t 0 ,,,.,.. 6.2.2 Non-Uniform Illumination ..................... .................... 54 6.3 Absolute Quantum Efficiency ............................ .. 58 .,,,i°°**. 6.3.1 Format-de pe ndent Sensitivity .................... " .......... 58 ao i. o. 6.4 Detector Background ................................................... 60 6.5 Stray Light ........................................ .........................