--------------------------------- Page 1 --------------------------------- Archive Interface Control Document Deep Impact Flight Data HRI Visible CCD (HRIV), MRI Visible CCD (MRI), and ITS Visible CCD (ITS) Raw and Calibrated Science Data Products Prepared by: Deep Impact Archive Team University of Maryland, Astronomy Department College Park, MD 20742 January 29, 2005 Last revised February 20, 2007 --------------------------------- Page 2 --------------------------------- Modification History -------------------- Date Name Description 2005-01-29 S. McLaughlin Created draft 2006-01-31 S. McLaughlin Updated draft to reflect changes to FITS-formatted data, file names, data set IDs, and PDS labels 2006-06-12 S. McLaughlin Updated for resolution of liens from the April 2006 PDS peer review of VIS flight data. 2006-09-28 S. McLaughlin Added Navigation data sets 2006-10-17 S. McLaughlin Added items to Project Documents and Data Set sections; updated text relating to Navigation data sets 2007-02-20 S. McLaughlin Updated for version 2.0 of the reduced data set 2007-09-27 S.McLaughlin Corrected INTEGRATION_DURATION calculation for VIS modes 4,6,7,8. --------------------------------- Page 3 --------------------------------- Table of Contents 1 INTRODUCTION .........................................................5 1.1 PURPOSE AND SCOPE ................................................5 1.2 APPLICABLE DOCUMENTS..............................................5 1.2.1 EXTERNAL STANDARD REFERENCES..................................5 1.2.2 PROJECT DOCUMENTS.............................................5 1.2.3 SCIENTIFIC REFERENCES.........................................6 1.3 CONTACT NAMES AND ADDRESSES.......................................8 2 INSTRUMENT DESIGN AND DATA PRODUCT GENERATION.........................9 2.1 INSTRUMENT OVERVIEW...............................................9 2.1.1 HRIV..........................................................9 2.1.2 MRI..........................................................11 2.1.3 ITS..........................................................13 2.1.4 INSTRUMENT MODES AND OVERCLOCK AREAS.........................15 2.1.5 FILTERS (HRIV AND MRI ONLY)..................................16 2.2 DATA SET AND DATA PRODUCT OVERVIEW...............................17 2.3 DATA PRODUCT GENERATION AND LABELING.............................19 2.3.1 CALIBRATION PROCESS..........................................19 2.3.2 IMAGE ORIENTATION AND PIXEL READOUT ORDER....................23 2.4 DATA SET ORGANIZATION............................................27 2.4.1 BROWSE.......................................................27 2.4.2 CALIB........................................................29 2.4.3 CATALOG......................................................29 2.4.4 DATA.........................................................30 2.4.5 DOCUMENT.....................................................30 2.4.6 INDEX........................................................30 2.5 DATA FILE NAMING CONVENTIONS AND PRODUCT IDS.....................31 2.6 STANDARDS USED IN DATA PRODUCT GENERATION........................33 2.6.1 PDS STANDARDS................................................33 2.6.2 TIME STANDARDS...............................................33 2.6.3 REFERENCE FRAME STANDARDS....................................33 2.6.4 IMAGE ORIENTATION............................................33 3 DETAILED SPECIFICATIONS OF DATA PRODUCTS.............................35 3.1 SAMPLE PDS LABELS................................................35 3.1.1 SCIENCE LEVEL 2 (RAW) VISIBLE CCD DATA PRODUCT ..............35 3.1.2 SCIENCE LEVEL 3/4 (CALIBRATED) VISIBLE CCD DATA PRODUCT......39 3.2 PDS OBJECT AND KEYWORD DEFINITIONS...............................44 --------------------------------- Page 4 --------------------------------- 4 USING THE DATA PRODUCTS..............................................57 4.1 INDEX FILES......................................................57 4.2 RELATED DATA SETS................................................57 4.3 FLIGHT HARDWARE CONSIDERATIONS...................................57 4.4 KNOWN ANOMALIES..................................................58 4.5 RECOMMENDED SOFTWARE TO READ DATA PRODUCTS.......................59 4.5.1 IDL..........................................................59 4.5.2 PDS-SBN TOOLS................................................59 5 TECHNICAL/PROGRAMMING INFORMATION....................................60 5.1 BRIEF DESCRIPTION OF ODL USED FOR PDS LABELS.....................60 5.2 ARCHITECTURE NOTES...............................................60 5.2.1 INTERNAL REPRESENTATION OF DATA TYPES........................60 5.2.2 FILE SYSTEM (ISO 9660).......................................60 5.3 FILE COMPRESSION FORMATS.........................................61 5.4 NAIF/SPICE.......................................................61 6 APPENDICES...........................................................62 6.1 GLOSSARY.........................................................62 6.2 ACRONYMS.........................................................63 6.3 DATA PROCESSING LEVELS ..........................................64 --------------------------------- Page 5 --------------------------------- 1 Introduction 1.1 Purpose The purpose and scope of this document is to define the PDS products for the science data, including some navigation images, acquired by the visible CCD instruments (HRIV, MRI, and ITS) during the cruise and encounter phases of the DI mission. This document is intended to provide enough information to enable users to understand and use the data products. This document includes information about how the data were processed, formatted, labeled, and identified. The structure of the data sets and an example of a raw and calibrated CCD image data product are included. This document is not intended to provide a detailed description of the CCD instruments nor does it provide methods for interpreting HRIV, MRI, and ITS data. A thorough discussion of the CCD instruments is provided in Hampton et al 2005 [4]. Klaasen, et al. 2005 [5] and Klaasen, et al. 2006 [15] provide an overview of the flight data and the calibration process, while Mastrodemos, et al. 2005 [16] discuss auto-navigation of which a subset of the images were archived. Carcich, 2006 [17] describes how the navigation images were created and calibrated for the archive. Also, Carcich, 2006 [18] discusses the known 1-2 second discrepancy between the spacecraft clocks and UTC. For discussions of expected scientific results and the properties of the comet 9P/Tempel 1, see Sunshine, et al. 2005 [6], Belton, et al. 2005 [7], Lisse, et al. 2005 [8], Thomas, et al. 2005 [9], Richardson, et al. 2005 [10], and Schultz, et al. 2005 [11]. For the history and dynamics of mission target, see Yeomans, et al. 2005 [12]. For overviews of the mission and scientific objectives, see A'Hearn, et al. 2005 [13] and Blume, 2005 [14]. 1.2 Applicable Documents 1.2.1 External Standard References [1] PDS Standards Reference, JPL, D-7669, Version 3.6, August 1, 2003 PDS Standards Reference, JPL, D-7669, Version 3.7, March 20, 2006 [2] PDS Data Dictionary, JPL, D-7116, Revision E, August 28, 2002 and the Deep Impact Local Data Dictionary created from the PDS Full Data Dictionary generated on December 6, 2006 (Version OPS) 1.2.2 Project Documents All of these documents are included in the Deep Impact Documentation Set (PDS volume ID DIDOC_0001): --------------------------------- Page 6 --------------------------------- [3] Deep Impact Project Data Management Plan, JPL, D-21386 [4] An Overview of the Instrument Suite for the Deep Impact Mission, Hampton et al, Space Science Reviews, 2005 [5] Deep Impact: The Anticipated Flight Data, Klaasen, et al. Space Science Reviews, 2005 [6] Expectations for Spectroscopy of Tempel 1 from Deep Impact, Sunshine, et al. Space Science Reviews, 2005 [7] Properties of the Nucleus of Comet 9P/Tempel 1: Target of the Deep Impact Mission, Belton, et al. Space Science Reviews, 2005 [8] The Coma of Comet 9P/Tempel 1, Lisse, et al. Space Science Reviews, 2005 [9] Comet Geology with Deep Impact Remote Sensing, Thomas, et al. Space Science Reviews, 2005 [10] Impact Cratering Theory and Modeling for the Deep Impact Mission: From Mission Planning to Data Analysis, Richardson, et al. Space Science Reviews, 2005 [11] Expectations for Crater Size and Photometric Evolution from the Dee Impact Collision, Schultz, et al. Space Science Reviews, 2005 [12] This History and Dynamics of Comet 9P/Tempel 1, Yoemans, et al. Space Science Reviews, 2005 [13] Deep Impact: A Large-Scale Active Experiment on a Cometary Nucleus, A'Hearn, et al. Space Science Reviews, 2005 [14] Deep Impact Mission Design, Blume, Space Science Reviews, 2005 [15] Deep Impact Instrument Calibration, Klaasen, et al. 2006, submitted to Optical Engineering [16] Autonomous Navigation for the Deep Impact Mission Encounter with Comet Tempel 1, Mastrodemos, et al. Space Science Reviews, 2005 [17] Deep Impact Navigation Images Report, Carcich, 2006 [18] Deep Impact Spacecraft Clock Correlation, Carcich, 2006 1.2.3 Scientific References Publications of results from Deep Impact will be provided here. The journal Icarus will publish a special edition of the results from Deep Impact. Ground-and space-based results will be included. The special edition should be published in 2007. [A] Deep Impact: Excavating Comet Tempel 1, A'Hearn, et al. 2005, Science, 310, 258-264 --------------------------------- Page 7 --------------------------------- [B] Deep Impact: Observations from a Worldwide Earth-based Campaign, Meech, et al. 2005, Science, 310, 265-269 [C] Parent Volatiles in Comet 9P/Tempel 1: Before and After Impact, Mumma, et al. 2005, Science, 310, 270-274 [D] Subaru Telescope Observations of Deep impact, Sugita, et al. 2005, Science, 310, 274-278 [E] The Dust Grains from Comet 9P/Tempel 1 Before and After the Encounter with Deep Impact, Harker, et al. 2005, Science, 310, 278-280 [F] Deep Impact Observations by OSIRIS Onboard the Rosetta Spacecraft, Keller, et al. 2005, Science, 310, 281-283 --------------------------------- Page 8 --------------------------------- 1.3 Contact Names and Addresses Michael A'Hearn Deep Impact Principal Investigator and PDS Small Bodies Node Manager Department of Astronomy University of Maryland College Park, MD 20742 301-405-6076 Stephanie McLaughlin Deep Impact Archive Team and PDS Small Bodies Node Staff Department of Astronomy University of Maryland College Park, MD 20742 301-405-3605 --------------------------------- Page 9 --------------------------------- 2 Instrument Design and Data Product Generation 2.1 Instrument Overview 2.1.1 HRIV The High Resolution Imager (HRI) consisted of a long-focal-length telescope with a dichroic beam splitter located in front of the focal plane, that reflected visible light (0.3 to 1.0 microns) through a filter wheel to a CCD for direct, optical imaging. The beam splitter transmitted the near-infrared light (1 to 5 microns) to a 2-prism spectrometer. For convenience, we considered these as two separate instruments, HRIV and HRII, sharing the telescope since the two focal planes operated in parallel asynchronously. The HRI telescope was a classical Cassegrain design with the following parameters: Primary aperture : 30.0 cm diameter, round Primary focal ratio : 4.5 Secondary Obscuration : 9.7 cm diameter, round Secondary magnification : 7.8x (net Cassegrain focal length 10.5 m) Back focal distance : 30.0 cm The dichroic beam-splitter had equal transmission and reflection occurring at about 1.05 microns. The filter wheel contained two clear apertures and 7 filters. Five of the filters were roughly 100 nanometers in bandwidth, centered at 450, 550, 650, 750, and 850 nanometers. The shortest-wavelength filter was effectively a short-wavelength pass filter starting at 400 nanometers and limited to about 340 nanometers on the short end by the rapid decline in beamsplitter reflectivity. The longest wavelength filter was a long-pass filter starting at 900 nanometers that used the CCD response to define the long-wavelength cutoff at about 960 nanometers. The visible detector was a 1024 x 1024 split-frame, frame-transfer CCD with 21-micron-square pixels, with each quadrant read out through a separate amplifier. The electronics allowed readout of centered sub-frames in multiples of 2: 64x64, 128x128, and so on, with or without rows of overscan. Transfer time, to move the two halves of the image from the exposing area to the two, shielded areas, was about 5.2 milliseconds. Readout time for a full frame was 1.8 seconds. The HRIV instrument in full-frame 1024 x 1024 mode had the following field-of-view characteristics: Pixel Size : 21 micrometers Pixel FOV : 2.0 microradians Instrument FOV : 2.0 milliradians or 0.118 degrees Surface Scale : 1.4 meters/pixel at 700 kilometers --------------------------------- Page 10 --------------------------------- There is a 1/3-pixel, horizontal gap for a clocking phase between the upper and lower halves of the CCD. It was inserted by the manufacturer to facilitate the simultaneous upward and downward reading of the upper and lower quadrants. The gap causes a 10 percent reduction in the sensitivity of the two central rows (that is, one row immediately above the gap and one below it). The HRIV instrument was calibrated by using in-flight data as well as pre-launch data taken during thermal-vacuum tests (TV2 and TV4) performed in 2002 and 2003. The calibration of the HRIV instrument is discussed by Klaasen, et al. 2006 [15]. The HRIV instrument generally performed as expected during flight. However, early images of stars indicated the HRI telescope was out of focus. An analysis showed the focus was forward of the CCD, so bakeouts were performed in late February and early March 2005 to improve the focus. The bakeouts reduced the defocus from 1.0 cm to 0.6 cm, which caused the width of star images to decrease from about 12 pixels to about 9 pixels. Star images continued to have a three-fold symmetry (six points) resulting from the three-point mounting of the primary and secondary mirrors. Most of the expected resolution can be regained by applying algorithms to deconvolve the HRIV images. For more information, see Klaasen, et al. 2006 [15]. For navigation imaging [16], an HRIV observation was typically snipped into one, or more, smaller rectangular areas containing the target(s) of interest reduce the download time. This processing was performed on board the spacecraft, and the snips for each observation were downloaded as individual packets. The Deep Impact Science Data Center at Cornell University reconstructed the packets for each observation into the original, raw, 1008x1008 pixel image, without overclock rows and columns [17]. The three instruments on the flyby spacecraft, HRII, HRIV and MRI, were mounted on a separate instrument platform together with the star trackers. The three instruments were nominally co-aligned. --------------------------------- Page 11 --------------------------------- 2.1.2 MRI The Medium Resolution Imager consisted of an f/17.5 Cassegrain telescope followed by a filter wheel feeding directly onto a CCD for direct, optical imaging. The MRI telescope was a classical Cassegrain design with the following parameters: Primary aperture : 12.0 cm diameter, round Primary focal ratio : 3.75 Secondary Obscuration : 6.6 cm diameter, round Secondary magnification : 4.75x (net Cassegrain focal length 210 cm) Back focal distance : 30.0 cm The filter wheel contained two clear apertures and 8 filters. The filters included duplicates of some of the medium-band filters in the High Resolution Images and filters that isolated OH, CN, and C2 as well as the green and violet continuum. These narrow-band filters were designed to match the Hale-Bopp filter sets used for ground-based programs since 1996. The longest wavelength filter was actually a long-pass filter that used the CCD response to define the long-wavelength cutoff at about 960 nanometers. The detector was a 1024 x 1024 split-frame, frame-transfer CCD with 21-micron-square pixels. The electronics allowed readout of centered sub-frames in multiples of 2: 64x64, 128x128, and so on, with or without rows of overscan. Transfer time, to move the two halves of the image from the exposing area to the two shielded areas, was about 5.2 milliseconds. There were readout amplifiers in each of the four quadrants. Readout time for a full frame was 1.8 seconds. Net pixel scale was 10 microradians/pixel (2 arcseconds/pixel). The MRI instrument in full-frame 1024 x 1024 mode had the following field-of-view characteristics: Pixel Size : 21 micrometers Pixel FOV : 10.0 microradians Instrument FOV : 10.0 milliradians or 0.587 degrees Surface Scale : 7 meters/pixel at 700 kilometers There is a 1/3-pixel, horizontal gap for a clocking phase between the upper and lower halves of the CCD. It was inserted by the manufacturer to facilitate the simultaneous upward and downward reading of the upper and lower quadrants. The gap causes a 10 percent reduction in the sensitivity of the two central rows (that is, one row immediately above the gap and one below it). The MRI instrument was calibrated by using in-flight data as well as pre-launch data taken during a thermal-vacuum test (TV4) performed in 2003. The calibration of the MRI instrument is discussed by Klaasen, et al. 2007 [15]. The MRI instrument generally performed as expected during flight. --------------------------------- Page 12 --------------------------------- For navigation imaging [16], an HRIV observation was typically snipped into one, or more, smaller rectangular areas containing the target(s) of interest reduce the download time. This processing was performed on board the spacecraft, and the snips for each observation were downloaded as individual packets. The Deep Impact Science Data Center at Cornell University reconstructed the packets for each observation into the original, raw, 1008x1008 pixel image, without overclock rows and columns [17]. The three instruments on the flyby spacecraft, HRII, HRIV, and MRI were mounted on a separate instrument platform together with the star trackers. The three instruments were nominally co-aligned. --------------------------------- Page 13 --------------------------------- 2.1.3 ITS The Impactor Targeting Sensor (ITS) consisted of an f/17.5 Cassegrain telescope feeding directly onto a CCD for direct, optical imaging. It was an exact clone of the Medium Resolution Instrument and its visible CCD camera except that the filter wheel had been deleted. In all other respects it was identical. The ITS telescope was a classical Cassegrain design with the following parameters: Primary aperture : 12.0 cm diameter, round Primary focal ratio : 3.75 Secondary Obscuration : 6.6 cm diameter, round Secondary magnification : 4.75x (net Cassegrain focal length 210 cm) Back focal distance : 30.0 cm The visible detector was a 1024 x 1024 split-frame, frame-transfer CCD with 21-micron-square pixels. The electronics allowed readout of centered sub-frames in multiples of 2: 64x64, 128x128, and so on, with or without rows of overscan. Transfer time, to move the two halves of the image from the exposing area to the two shielded areas, was about 5.2 millisecond. There were readout amplifiers in each of the four quadrants. Readout time for a full frame was 1.8 seconds. Net pixel scale was 10 microradians/pixel (2 arcseconds/pixel). Images were transmitted to the flyby spacecraft for re-transmission to Earth. The ITS instrument in full-frame 1024 x 1024 mode had the following field-of-view characteristics: Pixel Size : 21 micrometers Pixel FOV : 10.0 microradians Instrument FOV : 10.0 milliradians or 0.587 degrees Surface Scale : 0.2 meters/pixel at 20 kilometers There is a 1/3-pixel, horizontal gap for a clocking phase between the upper and lower halves of the CCD. It was inserted by the manufacturer to facilitate the simultaneous upward and downward reading of the upper and lower quadrants. The gap causes a 10 percent reduction in the sensitivity of the two central rows (that is, one row immediately above the gap and one below it). The ITS instrument was mounted behind the main deck of the Impactor spacecraft and looked through a rectangular cutout on one edge of the copper cratering mass at the front of the impactor. The ITS instrument was calibrated by using in-flight data as well aa pre-launch data taken during a thermal-vacuum test (TV3) performed in January and February 2003. The calibration of the ITS instrument is discussed in Klaasen, et al. 2006 [15]. The ITS instrument generally performed as expected during flight. --------------------------------- Page 14 --------------------------------- For navigation imaging [16], an HRIV observation was typically snipped into one, or more, smaller rectangular areas containing the target(s) of interest reduce the download time. This processing was performed on board the spacecraft, and the snips for each observation were downloaded as individual packets. The Deep Impact Science Data Center at Cornell University reconstructed the packets for each observation into the original, raw, 1008x1008 pixel image, without overclock rows and columns [17]. The ITS instrument was mounted behind the main deck of the impactor spacecraft and looked through a rectangular cutout on one edge of the copper cratering mass at the front of the impactor. --------------------------------- Page 15 --------------------------------- 2.1.4 Instrument Modes and Overclock Areas The imaging modes for the CCD instruments are provided below. Modes where the light blocker opens and closes are identified by ''shuttered'' in the Mode column. Modes where the light blocker remained open are identified by ''unshuttered''. The CCD arrays had several serial overclock columns (line samples) and several parallel overclock rows (lines) around the edge of the array. Pixels in the overclock areas were excluded from the MINIMUM and MAXIMUM values in the PDS labels. See Hampton, et al. 2005 [4] for more details about the instrument modes and the overclock rows and columns. Serial Parall Min Frame- Img O'clck O'clck Cmmd to-Frame Mode Size Cols Rows Exp Time # Mnemonic Mode (pix) (x-pix) (y-pix) (s) (s) - -------- ------------------------- ---- ------- ------- --- --------- 1 FF Full Frame (shuttered) 1024 8 8 0 1.634 2 SF1 Sub-Frame 1 (shuttered) 512 4 4 0 0.737 3 SF2S Sub-Frame 2 (shuttered) 256 4 4 0 0.430 4 SF2N Sub-Frame 2 (unshuttered) 256 4 4 4 0.232 5 SF3S Sub-Frame 3 (shuttered) 128 2 2 0 0.312 6 SF3N Sub-Frame 4 (unshuttered) 128 2 2 4 0.113 7 SF4O Sub-Frame 4 (unshuttered) 64 0 1 4 0.062 8 SF4NO Sub-Frame 4 (unshuttered) 64 0 0 4 0.062 8 FFD Diagnostic (shuttered) 1024 8 8 0 1.634 --------------------------------- Page 16 --------------------------------- 2.1.5 Filters (HRIV and MRI only) The characteristics of the filters for the HRIV and MRI instruments were: Filter ---------MRI Filter---------- ---HRI Filter-- Wheel Center Width Target Center Width Position (nm) (nm) Measurement (nm) (nm) -------- ----- -------- ------------ ----- -------- 1 650 >700(1) Context 650 >700(1) 2 514 11.8 C2 in coma 450 100 3 526 5.6 Dust in coma 550 100 4 750 100 Context 350 100(3) 5 950 100(2) Context 950 100(3) 6 650 >700(1) Context 650 >700(1) 7 387 6.2 CN in coma 750 100 8 345 6.8 Dust in coma 850 100 9 309 6.2 OH in coma 650 100 (1) Filters in positions 1 & 6 are uncoated and not band limited (2) The 950 nm filter is longpass (3) The coating on the 350 nm filter is shortpass, the substrate limits the short wavelength throughput --------------------------------- Page 17 --------------------------------- 2.2 Data Set and Data Product Overview For the PDS archive, flight data are grouped into two, general mission phases: Phase Start Date End Date Targets --------- ----------- ----------- ------------------------------- CRUISE 12 Jan 2005 30 Apr 2005 In-flight Calibrations ENCOUNTER 01 May 2005 13 Jul 2005 Tempel 1 Imaging, In-flight Calibrations HRIV, MRI, and ITS data products for the flight phase of the DI mission were grouped into the following data sets in the PDS archive: DIF-CAL-HRIV-2-9P-CRUISE-V1.0 DIF-CAL-MRI-29P-CRUISE-V1.0 DII-CAL-ITS-2-9P-CRUISE-V1.0 - Cruise - Raw, calibration data in units data number. - 2-D FITS images (*.fit) with an extension for a quality flag map. DIF-C-HRIV-2-9P-ENCOUNTER-V1.0 DIF-C-MRI-2-9P-ENCOUNTER-V1.0 DII-C-ITS-2-9P-ENCOUNTER-V1.0 - Encounter - Raw comet images and calibration data in units of data number. - 2-D FITS images (*.fit) with an extension for a quality flag map. DIF-C-HRIV-3/4-9P-ENCOUNTER-V2.0 DIF-C-MRI-3/4-9P-ENCOUNTER-V2.0 DII-C-ITS-3/4-9P-ENCOUNTER-V2.0 - Encounter - Version 2.0 supersedes version 1.0 below. The calibration process was improved and the version of the archived SPICE kernels was used to calculate geometric parameters. Calibrated comet data in physical units of radiance (not cleaned and reversible [RADREV] or irreversibly cleaned [RAD]) or reflectance (I-over-F, irreversibly cleaned [IF]). - 2-D FITS images with extensions for a quality flag map, and a signal-to-noise map, (*.fit). Calibration files: Nominally, FITS image files (*.fit) and ASCII tables in the /CALIB subdirectory. DIF-C-HRIV-3/4-9P-ENCOUNTER-V1.0 DIF-C-MRI-3/4-9P-ENCOUNTER-V1.0 DII-C-ITS-3/4-9P-ENCOUNTER-V1.0 - Superseded by version 2.0 above - Encounter - Only calibrated comet data in physical units of radiance, (not cleaned and reversible [RADREV]). - 2-D FITS images with extensions for a quality flag map, and a signal-to-noise map, (*.fit). Calibration files: Nominally, FITS image files (*.fit) and ASCII tables in the /CALIB subdirectory. DIF-CAL-HRIV-2-NAV-9P-CRUISE-V1.0 DIF-CAL-MRI-2-NAV-9P-CRUISE-V1.0 DII-CAL-ITS-2-NAV-9P-CRUISE-V1.0 - Cruise - Raw, calibration images for navigation in units of data number. - 2-D FITS images (*.fit) without an image quality map. DIF-C-HRIV-2-NAV-9P-ENCOUNTER-V1.0 DIF-C-MRI-2-NAV-9P-ENCOUNTER-V1.0 DII-C-ITS-2-NAV-9P-ENCOUNTER-V1.0 - Encounter - Raw comet and calibration images for navigation in units of data number. - 2-D FITS images (*.fit) without an image quality map. --------------------------------- Page 18 --------------------------------- DIF-C-HRIV-3-NAV-9P-ENCOUNTER-V1.0 DIF-C-MRI-3-NAV-9P-ENCOUNTER-V1.0 DII-C-ITS-3-NAV-9P-ENCOUNTER-V1.0 - Encounter - Only calibrated comet images for navigation in physical units of radiance (not cleaned and reversible [RADREV]). - 2-D FITS images with extensions for a quality flag map, and a signal-to-noise map, (*.fit). Calibration files: Nominally, FITS image files (*.fit) and ASCII tables in the /CALIB subdirectory. DIF-C-HRIV/MRI/ITS-5-TEMPEL1-SHAPE-V1.0 DIF-C-HRII-5-TEMPEL1-SURF-TEMP-MAPS-V1.0 - Encounter - Derived data such as shape models, and thermal maps of the surface. - Nominally: ASCII tables (*.tab) and 2-D FITS images (*.fit). --------------------------------- Page 19 --------------------------------- 2.3 Data Product Generation and Labeling All raw and calibrated HRIV, MRI, and ITS FITS image files were produced in the DI data pipeline that is maintained by the DI SDC at Cornell University. The data pipeline takes raw telemetry with imbedded data, as downloaded from the DI flyby spacecraft, and constructs raw FITS image files. The data pipeline inputs the raw FITS files, calibrates the data, and outputs calibrated FITS images. The calibration process is described below. For details about the SDC and flow of data, refer to the DI PDMP [3], Klaasen, et al. 2005 [5], and Klaasen, et al. 2006 [15]. Calibration files, such as flat fields, were the result of the DI science team's analysis of ground-based thermal-vacuum and in-flight calibration data. Calibration files were stored at the DI SDC and used by the calibration portion of the DI data pipeline. Calibration files used to reduced HRIV, MRI, and ITS images are included in the reduced Deep Impact data sets. PDS data labels and index tables for raw and calibrated data products were generated by Applied Coherent Technology Corporation (ACT) of Herndon, Virginia. All PDS data labels are detached. 2.3.1 Calibration Process The goal of the data calibration process for the HRIV, MRI, and ITS instruments was to: - Convert the raw data numbers (DNs) returned from each pixel in each image or spectrum to absolute scientific units of scene radiance or scene reflectance (I-over-F or I/F). - Determine from where in the scene or its surroundings the photons originated that produced the signal in each pixel. The analysis of thermal-vacuum and in-flight calibration data and the resulting calibration pipeline is presented in the DI Calibration Pipeline paper by Klaasen, et al. 2006 [15] and in the DI Anticipated Flight Data publication by Klaasen, et al. 2005 [5]. Carcich, 2006 [17] discusses how the pipeline was used to calibrate navigation images. The following excerpt from the DI Instrument Calibration paper [15] is provided here as an overview of the pipeline. --------------------------------- Page 20 --------------------------------- Figure 0 - A flowchart describing the data processing pipeline used to calibrate Deep Impact images. Some modules are not applied to all instruments. Input calibration files, such as the Lookup tables for decompression, are identified by red text. There are a few exceptions to this flow chart for navigation images. When reducing navigation data, dark subtraction was performed on board the spacecraft, and a specific bias correction was derived for each quadrant because there were no overclocks for navigation frames. ''Standard Steps For each image, there is a standard set of procedures and settings applied in our pipeline processing in order to calibrate the images automatically (see Figure 0). In general, these default settings are the best the science team has been able to derive for the data set as a whole and thus do not necessarily reflect the best possible processing for any particular image. However, there are some observations around encounter, especially with the IR spectrometer, that contain very valuable scientific information but are not processed --------------------------------- Page 21 --------------------------------- optimally by the default settings. For these cases, the automated pipeline has the ability to specify special settings for particular observations. The standard pipeline begins by decompressing the image if it was compressed on the spacecraft. Images can be compressed using one of four 14-bit to 8-bit lookup tables optimized for different types of exposures. To uncompress the images, a reverse lookup table is used which maps each 8-bit value to median of all corresponding 14-bit values. All saturated pixels are flagged in the quality map. Then an IR image is linearized. A VIS image does not need this step because the instrument responds linearly. Next, a dark frame is subtracted from the image. If a dark frame was created by the science team for the specific observation, then it is subtracted. Otherwise, a dark model is used to generate the frame. After the dark subtraction, a flat field is only applied to unbinned IR images because the best binned-mode flat field does not seem to provide any noticeable improvement in SNR. After bad pixels are flagged, the image is radiometrically calibrated to produce a radiance image in W/[m2 sr um] and an I/F image. For a VIS image, this is simply done by dividing the image by integration time and then multiplying by the appropriate conversion factor for the given filter and desired output. For an IR image, the procedure is more complicated as the absolute calibration is wavelength dependent, which in turn is temperature dependent. First, the wavelength and bandwidth for each pixel are calculated. Then, each pixel is multiplied by the appropriate wavelength-dependent calibration factor and divided by integration time and the pixel's spectral bandwidth. Once this radiance image is created, a copy is converted to I/F by dividing by the solar spectrum at the target's distance from the sun and then multiplying by pi. I/F data are unitless. At this point, two reversible data products have been created, one radiance image and one I/F image, and copies are run through the rest of the pipeline, which performs a series of non-reversible steps. First, the data are interpolated over the bad pixels and gaps. For a VIS image, this interpolation is performed using thin plate splines anchored by the valid data around the edges of each hole. For an IR image, a linear interpolation is performed in the spatial dimension only. Next, a despiking routine is applied in order to remove cosmic rays. This routine performs a sigma filter by calculating the median of each NxN box, where N is odd, and then replacing the central pixel with the median if it is more than M median deviations from the median. By default, both M and N are set to 3. The median deviation of a set S is defined as: Med(| S - Med(S) |). Lastly, a VIS image is deconvolved if this option is turned on for the pipeline. This is especially important for the HRIVIS instrument that is out of focus. --------------------------------- Page 22 --------------------------------- Optional Steps Beyond the automated calibration pipeline described above, a manual calibration can be performed where the user can specify his/her own settings and calibration files for each step. Also, any processing module can be disabled, and there are two extra ones that can be enabled. The first such module is a noise-reduction module that is applied after the despiking routine. This applies the BayesShrink wavelet thresholding algorithm (Chang, et al. 2000) with a robust mean noise estimator (Johnston and Silverman, 1997) to remove some of the noise. The other step that can be enabled applies a rubber sheet geometric distortion correction. This is not normally applied as the optical distortion though the telescope is minimal.'' See the instrument calibration document [15] for a detailed description of the image quality and signal-to-noise maps created by the pipeline and appended to the primary FITS image as image extensions. --------------------------------- Page 23 --------------------------------- 2.3.2 Image Orientation and Pixel Readout Order The following section was excerpted from the DI Calibration Pipeline paper by Klaasen et al. 2006 [15]. ''In order to understand the data from the instruments at the level of calibrations, it is important to understand both the way in which pixels are read out from the detector and also the way in which they are stored in the resultant FITS/PDS images. Throughout this paper we identify the four physical quadrants of the detectors as A through D (or just A and B in the case of the IR detector, which only uses 2 of the quadrants on the physical detector). The nomenclature in Figures 1, 2, and 3 assumes the standard convention for displaying FITS files: The faster-varying index in the data file (for line samples) is displayed to the right and the slower varying index (for lines) is displayed up (in PDS images the directions are controlled by keywords, which for our images are set to match the standard FITS display). Thus, the first byte of the FITS/PDS file appears in the lower-left corner of the window and the last byte in the FITS/PDS file appears in the upper-right. All FITS/PDS archival images are structured to display a true image of the sky, with arbitrary rotation about the center of the image (ecliptic north is to the right in this particular image), rather than a mirror image of the sky. The header information in the downlinked data is always written in the first 100 bytes of quadrant A. Figure 1. A full-frame, HRIV frame taken shortly before impact, displayed with the FITS convention. This orientation reproduces a true sky image. The first and last bytes are those read from the FITS file and are not connected with the order of readout. Quadrants A, B, C and D noted throughout this paper are labeled in the image. --------------------------------- Page 24 --------------------------------- In Figure 1 we show an in-flight, visible image from HRI, in which the directions in the labels are referred to by the order of the bytes (pixels) in the archived data files. The images from the thermal-vacuum calibrations have the same orientation. For MRI and ITS, the different number of reflections in the optical path of the instruments lead to a right-left mirroring between the physical quadrants and the image of the sky and also a mirroring between the thermal-vacuum calibrations and the in-flight data. Since the quadrant labeling refers to physical quadrants, the thermal-vacuum calibrations have the same orientation of the quadrants for all three instruments (A in upper left and D in lower right) but they have different orientations for in-flight data, i.e., the in-flight data for MRI and ITS have quadrant A in the upper right and quadrant D in the lower left for normally displayed FITS images. Thus the quadrants for in-flight images from MRI and ITS are shown in Figure 2. Figure 2. A full-frame, MRI frame taken at nearly the same time as the HRIV image in Figure 1. Displayed with the FITS convention, a true sky image is reproduced. The first and last bytes are those read from the FITS file and are not connected with the order of readout. Quadrants A, B, C and D noted throughout this paper are labeled in the image. The readout order of the pixels is independent of the order of bytes in the FITS images since each quadrant is read out independently in parallel and the bytes are then rearranged into an image. The direction of the split-frame rapid transfer is up and down in Figures 1 and 2, symmetric about the centerline. This affects the smear of bright sources in short exposures. After shifting to the shielded region of the detector, the top and bottom rows are read out first (top and bottom of the relevant subframe when only a subframe is read), --------------------------------- Page 25 --------------------------------- and in each of these rows the outermost pixels are read out first. The rows immediately above and below the centerline are read out last, and within these two rows, the pixels immediately adjacent to the centerline are read out last. The header information is overwritten on the first 100 bytes of quadrant A (upper left quadrant for HRI inflight images and upper right quadrant for in-flight images with MRI and ITS) after the image is constructed. Overclocked pixels and rows are read out after the true pixels, but they are moved to the outside of the FITS/PDS image to preserve the contiguity of the image in normal displays. The situation for the near-IR spectrometer is shown in Figure 3. The normally displayed image, whether using the FITS standard display convention or displaying via the relevant PDS keywords, will have wavelength increasing from left to right and the long spatial dimension of the slit oriented vertically. The vertical spatial direction in the spectrometer image is the same as in the HRI visible image, terminator at the top and limb at the bottom for a spectrum at the time of Figure 1. There are only two quadrants used although the actual detector has two additional quadrants that are not exposed to light and are not read out. The orientation is the same both for in-flight data and for thermal-vacuum calibrations, with A on the left in a standard FITS/PDS display while B is on the right. When the image is constructed, the header information is overwritten on the first 100 bytes of quadrant A. Figure 3. A full-frame, HRII frame taken shortly before impact, displayed with the FITS convention. For this FITS display, the wavelength increases as the fastest-varying axis increases to the right. The slowest-varying axis is the spatial direction along the slit. The first and last bytes are those read from the FITS file and are not connected with the order of readout. IR quadrants A and B noted throughout this paper are labeled in the image. Since the IR detector is reset and read out on a pixel-by-pixel basis, the readout order affects the actual time at which a pixel is exposed, unlike the situation for the visible CCDs. Each pixel has the same exposure duration, but the exposure of the last pair of pixels read out does not start until one delay-time before the first pair of pixels is read out. As with the lower half of the visible images, the bottom row is read out first and within that row the outermost (leftmost and rightmost) pixels are read out first. The --------------------------------- Page 26 --------------------------------- spectral row at the upper end of the slit in this standard display is read out last and, within that row the two pixels on either side of the center-line are read out last. The header information is again written over the first 100 bytes of quadrant A, now in the lower left of a normal display. --------------------------------- Page 27 --------------------------------- 2.4 Data Set Organization HRIV, MRI, and ITS flight data sets are organized using the subdirectories recommended by the PDS standards: - Browse (optional) - Calib (for reduced data sets only) - Catalog - Data - Document - Index 2.4.1 Browse This directory contains a thumbnail file and a full-size JPEG file representing each CCD image found in the /data/radrev/ directory. The browse images are grouped by the observation day of year. The project did not generate thumbnails for navigation images; therefore the navigation data sets do not have a browse directory. 2.4.2 Calib This directory contains the files used to calibrate raw Tempel 1 data and is only included in the reduced data set. The DI science team produced these files as a result of the analysis of thermal-vacuum and in-flight calibration data. The calibration files are grouped into the following subdirectories: ABSCALVS - This subdirectory contains one ASCII text table of the absolute calibration constants for each instrument (image) mode. specifies the constant for converting raw data numbers to units of radiance, W/(m**2 sr um). The second column specifies the constant for converting from units of radiance to units of reflectance (i.e., I-over-F or the observed radiance over the input solar radiance, unitless). ADCLUT - This subdirectory contains a lookup table for the correcting for uneven bit weighting caused by the analog-to-digital conversion. The single table applies to all instrument modes. As of this archive, the corrections had not been derived. Therefore, the input pixel values are the same as the output values to prevent the automated calibration pipeline from changing the data. BADPIX - This subdirectory contains maps that identify bad pixels for each instrument mode. Bad pixels are set to a value of 1. Good pixels are set to 0. Pixels in the serial and parallel overclock columns and rows are flagged as good (0). For each image mode, there is one row of warm pixels near the top and bottom edge. These rows are flagged as bad (1). --------------------------------- Page 28 --------------------------------- BIAS - This subdirectory contains a bias correction map for each instrument mode. DECOMPRS - This subdirectory contains the four lossy lookup tables used to decompress raw data. DRKMODEL - This subdirectory contains maps for modeling the dark signal for each instrument mode. FILTERS - This subdirectory contains one transmission profile table each filter. FLAT - This subdirectory contains flat fields for every combination instrument mode and filter. PSF - This subdirectory contains a map of the point-spread function for each HRIV or MRI filter. For ITS, only one PSF file is provided. For MRI and ITS, the PSF is simply a centered-delta function. For HRIV, the PSF files can be used to deconvolve an out-of-focus HRIV image. XTALK - This subdirectory contains tables that specify the amount of gain from electronic cross talk that occurs between all possible combinations of the four quadrants of the CCD. There is one table for each instrument mode. However, after this data set was delivered to PDS for the review, it was discovered that the calibration pipeline used in incorrect tables, containing all zeros, for instrument modes 2 through 9. The tables for these modes should have been identical to the table for mode 1. However, this omission has a negligible effect (less than one percent) on the calibrated data. --------------------------------- Page 29 --------------------------------- 2.4.3 Catalog This directory contains catalog files required by PDS: - DATASET.CAT - Description of the data set - HRIV.CAT, MRI.CAT, or ITS.CAT - Description of the instrument - DIF.CAT or DII.CAT - Description of the flyby or impactor spacecraft - DEEP_IMPACT.CAT - Description of the mission - PERSON.CAT - Contact information for personnel who created the data set - REFERENCE.CAT - List of publications cited in the catalog files - 9P_TEMPEL_1_1867_G1.CAT - Catalog file for the mission target - CALIBRATION.CAT - Generic catalog file for calibration targets (TARGET_DESC keywords in the PDS data labels provides the specific target name such as Jupiter or Canopus) 2.4.4 Data This directory contains the raw and calibrated CCD image data, grouped by the year, day of year of the observation, and level of calibration (for calibrated images): /data//// where: - year is 4 digits - day of year is 3 digits - level = not used for raw data, RADREV for calibrated but uncleaned data in units of radiance (calibration steps can be reversed to get back to the raw DN), RAD for calibrated and irreversibly cleaned data in units of radiance, and IF for calibrated and irreversibly cleaned data in units of reflectance (I-over-F). Calibration products for the CCD instruments are located in the data directory of the calibration data set and are grouped by type of calibration file, for example: /data/{type}/ where: - type = FLAT or BIAS, for example --------------------------------- Page 30 --------------------------------- 2.4.5 Document A separate volume, DIDOC_0001, provides documentation pertaining to the raw and reduced HRII, HRIV, MRI, and ITS science and navigation data sets, as well the entire DI archive, and nominally includes: - Image logs with notes from the encounter, starting at 28 hours before impact. - The instrument calibration paper by Klaasen, et al. 2006 [15] - Navigation images report by Carcich, 2006 [17] - List cross-referencing raw and reduced navigation FITS file names - Chapters in Deep Impact Mission: Looking Beneath the Surface of a Cometary Nucleus, published by Space Science Reviews - A report about the known discrepancy between the two spacecraft clocks and UTC - A description of the quaternion found in the PDS labels - A day of year calendar for 2005 (converts day of year to month and day) - The IDL programs used for the calibration pipeline (provided only as documentation; the programs are not supported) - The DI local Data Dictionary which consists of the full PDS Data Dictionary plus keywords specific to DI, such as DEEPIMPACT:IMAGE_MID_TIME - The Project Data Management Plan for the mission - This Archive Interface Control Document 2.4.6 Index This directory contains a file that serves as an index into the products in the data directory. Index file includes all of the values found in the data label that are relevant to science, such as INSTRUMENT_IMAGE_MODE, INTEGRATION_DURATION, etc. --------------------------------- Page 31 --------------------------------- 2.5 Data File Naming Conventions and Product IDs The naming convention for the products in the data directory for the raw and calibrated science (non-navigation) data sets is: hicccccccccc_sssssss_nnn{_xx}.fit or .lbl where: - hi = instrument (''hv'' for HRIV, ''mv'' for MRI, or ''iv'' for ITS) - cccccccccc = spacecraft clock count at the mid-point of the exposure, without the clock partition string - ssssssss = exposure ID - nnn = image number with exposure ID - xx = rr for RADREV (units of radiance, calibrated, not cleaned but can be reversed to raw DN), r for RAD (units of radiance, calibrated and irreversibly cleaned), if for IF (units of reflectance or I-over-F, calibrated and irreversibly cleaned), not used for RAW The naming convention for the products in the data directory for the raw navigation data sets is: dxissssssss_yyyydddhhmmssuuu.lbl or fit where: - d = Deep Impact - x = image usage (A for AutoNav or O for OpNav) - i = instrument (HRIV, MRI, or ITS) - cccccccccc = spacecraft clock count at the mid-point of the exposure, without the clock partition string - ssssssss = exposure IDs for science data; image number within an exposure ID was always one of one - yyyy = ground-received time (GRT) year - ddd = GRT day of year - hhmmss = GRT hours, minutes, and seconds - uuu = suffix to provide uniqueness when two images were acquired or processed within the same second It is important to note that a different file naming convention was used for the calibrated NAV images. A cross-reference of the raw and calibrated file names is included on the Deep Impact documentation volume. Some images were downloaded more than once and processed by the SDC. For this case, each version of a raw image was included in this data set. For multiple downloads of one image, the exposure IDs in the file names are identical but the ground-received times are different. --------------------------------- Page 32 --------------------------------- The naming convention for the products in the data directory for the calibrated navigation data sets is: ixcccccccccc_sssssss_nnn{_xx}.fit or .lbl where: - i = instrument (''h'' for HRIV, ''m'' for MRI, or ''i'' for ITS) - x = image usage (A for AutoNav or O for OpNav) - cccccccccc = spacecraft clock count at the mid-point of the exposure, without the clock partition string - ssssssss = exposure ID - nnn = image number with exposure ID - xx = rr for RADREV (units of radiance, calibrated, not cleaned but can be reversed to raw DN) --------------------------------- Page 33 --------------------------------- 2.6 Standards Used in Data Product Generation 2.6.1 PDS Standards The version 3, PDS3, of the PDS Standards Reference [1] and revision E of the PDS Data Dictionary and the Deep Impact Local Data Dictionary [2] were followed when generating the data products. 2.6.2 Time Standards Times given in the PDS labels are UTC, unless otherwise specified. 2.6.3 Reference Frame Standards PDS labels for raw and calibrated data products contain geometry keywords and values based on the inertial reference frames Earth mean equator J2000 (EMEJ2000). The exception is the ECLIP_NORTH_CLOCK_ANGLE which in the Ecliptic J2000 frame (ECLIPJ2000). Definitions of geometry keywords are defined in section 3.2 of this document and explicitly refer the appropriate reference frames. 2.6.4 Image Orientation For consistency, raw and reduced images, as produced by the DI data pipeline and analyzed by the science team, are stored in this PDS archive. In particular, the top of an HRIV and MRI image corresponds to the top of the vertical slit of the IR (HRII). The LINE_DISPLAY_DIRECTION and SAMPLE_DISPLAY_DIRECTION keywords in the product labels describe how the data should be displayed. For raw and calibrated image, samples are displayed from left to right and lines from the bottom to the top, such that the first pixel read from the FITS file is displayed in the lower-left corner of a graphics window and the last pixel in the upper-right. Although this orientation provides views ''as seen'' by the flyby spacecraft, it places ecliptic north approximately to the right, ecliptic east approximately to the top, and the sun towards the bottom for all HRIV and MRI images from approach to shield mode at encounter. As the flyby spacecraft came out of shield mode, it turned and looked back at Tempel 1. Therefore, all post-images have ecliptic north approximately to the left and the sun towards the bottom. The orientation of the impactor spacecraft after its release from the flyby produced ITS images with ecliptic north was toward the upper right corner --------------------------------- Page 34 --------------------------------- and the sun toward the lower right. This topic is discussed in Klaasen, et al. 2006 [15]. See section 2.3.2 for more information. --------------------------------- Page 35 --------------------------------- 3 Detailed Specifications of Data Products 3.1 Sample PDS Labels This section provides sample PDS labels for raw and calibrated HRIV, MRI, and ITS FITS data, including navigation images. Data products for the HRIV, MRI, and ITS instruments have self-consistent formats. Samples of data products for only the HRIV instrument are provided here. 3.1.1 Science Level 2 (Raw) Visible CCD Data Product This is an example of a PDS label for a raw HRIV FITS image, in units of data number. Labels for raw HRIV, MRI, and ITS navigation images are identical to the sample below, except several keywords in the FITS header do not exist because the information was not included in the minimal image headers. PDS_VERSION_ID = PDS3 RECORD_TYPE = "FIXED_LENGTH" RECORD_BYTES = 2880 FILE_RECORDS = 289 ^HEADER = "HV0173628244_9000007_001.FIT" ^IMAGE = ("HV0173628244_9000007_001.FIT", 14) ^EXTENSION_QUALITY_HEADER = ("HV0173628244_9000007_001.FIT", 197) ^EXTENSION_QUALITY_IMAGE = ("HV0173628244_9000007_001.FIT", 198) DATA_SET_ID = "DIF-C-HRIV-2-9P-ENCOUNTER-V1.0" INSTRUMENT_HOST_NAME = "DEEP IMPACT FLYBY SPACECRAFT" INSTRUMENT_HOST_ID = "DIF" INSTRUMENT_NAME = " DEEP IMPACT HIGH RESOLUTION INSTRUMENT - VISIBLE CCD" INSTRUMENT_ID = "HRIV" /***** PRODUCT INFORMATION *****/ PRODUCT_ID = "HV0173628244_9000007_001_FIT" PRODUCT_NAME = " DI FLIGHT DATA, RAW HRIV, HV0173628244_9000007_001.FIT" PRODUCT_CREATION_TIME = 2006-06-14T20:17:05 PRODUCT_TYPE = "EDR" /***** TIME INFORMATION *****/ START_TIME = 2005-07-03T02:06:54.263 STOP_TIME = 2005-07-03T02:06:55.763 DEEPIMPACT:IMAGE_MID_TIME = 2005-07-03T02:06:55.013 START_JULIAN_DATE_VALUE = 2453554.5881280 STOP_JULIAN_DATE_VALUE = 2453554.5881454 MID_JULIAN_DATE_VALUE = 2453554.5881367 SPACECRAFT_CLOCK_START_COUNT = "1/0173628243.143" SPACECRAFT_CLOCK_STOP_COUNT = "1/0173628245.015" DEEPIMPACT:SPACECRAFT_CLOCK_MID_COUNT = "1/0173628244.079" DEEPIMPACT:TIME_FROM_IMPACT_VALUE = -99460.808 EARTH_RECEIVED_TIME = 2005-07-03T02:14:15.348 /***** OBSERVATION INFORMATION *****/ MISSION_PHASE_NAME = "9P ENCOUNTER" DEEPIMPACT:MISSION_ACTIVITY_TYPE = "CONTINUOUS COMET IMAGING" OBSERVATION_TYPE = "EIGHT-FILTER SET EVERY HOUR" TARGET_NAME = "9P/TEMPEL 1 (1867 G1)" TARGET_DESC = "9P/TEMPEL 1 (1867 G1)" --------------------------------- Page 36 --------------------------------- INSTRUMENT_MODE_ID = 2 DEEPIMPACT:COMPRESSED_IMAGE_VALUE = "UNCOMPRESSED" COMPRESSOR_ID = "N/A" OBSERVATION_ID = 9000007 IMAGE_NUMBER = 1 DEEPIMPACT:COMMANDED_IMAGE_COUNT = 1 FILTER_NUMBER = 6 FILTER_NAME = "CLEAR6" CENTER_FILTER_WAVELENGTH = 650 DEEPIMPACT:MINIMUM_EXPOSURE_DURATION = 3.500 DEEPIMPACT:COMMANDED_EXPOSURE_DURATION = 1497.000 DEEPIMPACT:INTERFRAME_DELAY_DURATION = 0.000 DEEPIMPACT:INTEGRATION_DURATION = 1500.500 INSTRUMENT_TEMPERATURE = ( 301.085 , 301.220 , 293.094 , 299.235 , 271.769 , 169.922 , 137.828 , 136.716 , 129.781 , 136.879 , 84.172 ) INSTRUMENT_TEMPERATURE_POINT = ( "INSTRUMENT CONTROLLER PROCESSING BOARD", "CCD SIGNAL PROCESSING BOARD", "IR SIGNAL PROCESSING BOARD", "LVPS SIGNAL PROCESSING BOARD", "CCD PREAMP BOX", "CCD ON-CHIP SENSOR", "PRISMS", "PRIMARY MIRROR", "SECONDARY MIRROR", "SPECTRAL IMAGING MODULE COVER", "IR FPA ON-CHIP SENSOR" ) INSTRUMENT_VOLTAGE = ( 1.206 , 1.213 , 1.206 , 1.217 , 5.123 , 5.120 , 5.113 , 5.105 , 5.027 , -4.985 , 5.002 , -9.187 , 0.245 , 0.742 , 3.407 , "UNK" ) INSTRUMENT_VOLTAGE_POINT = ( "CCD OFFSET FROM ADC REF QUAD A", "CCD OFFSET FROM ADC REF QUAD B", "CCD OFFSET FROM ADC REF QUAD C", "CCD OFFSET FROM ADC REF QUAD D", "CCD OUTPUT AMP DRAIN QUAD A", "CCD OUTPUT AMP DRAIN QUAD B", "CCD OUTPUT AMP DRAIN QUAD C", "CCD OUTPUT AMP DRAIN QUAD D", "CCD SERIAL CLOCK POSITIVE", "CCD SERIAL CLOCK NEGATIVE", "CCD PARALLEL CLOCK POSITIVE", "CCD PARALLEL CLOCK NEGATIVE", "IR RESET", "IR SUBSTRATE", "IR BIASGATE", "IR CALIB LAMP" ) /***** IMAGE INFORMATION *****/ HORIZONTAL_PIXEL_SCALE = 2048.983 VERTICAL_PIXEL_SCALE = 2048.983 --------------------------------- Page 37 --------------------------------- /***** GEOMETRY PARAMETERS *****/ NOTE = " Earth Mean Equator and Vernal Equinox J2000 is the inertial reference system used to specify observational geometry. Geometric parameters are based on the best available SPICE data at the time this product was created. Refer to the Deep Impact SPICE archive for the most current observational geometry. The spacecraft clock count at the middle of the exposure was used to derive the geometry." RIGHT_ASCENSION = 201.420367314 DECLINATION = 25.035073706 CELESTIAL_NORTH_CLOCK_ANGLE = 133.7396 SOLAR_NORTH_POLE_CLOCK_ANGLE = 108.051 QUATERNION = (0.827605818751, 0.289183970834, -0.452533027354, -0.163263893548) QUATERNION_DESC = "QUATERNION_DESC.ASC" DEEPIMPACT:INST_EMEJ2000_VELOCITY_VECTOR = (-1.481594643370e-007 ,1.168240855000e-006 , 9.458584315910e-008 ) DEEPIMPACT:TARGET_SC_POSITION_VECTOR = (864149.437 , 339014.841 , -433471.085 ) DEEPIMPACT:TARGET_SC_VELOCITY_VECTOR = (-8.6863 , -3.4081 , 4.3569 ) TARGET_CENTER_DISTANCE = 1024491.3340 SC_SUN_POSITION_VECTOR = (89518957.536 , 189795055.268 , 80807358.928 ) SPACECRAFT_SOLAR_DISTANCE = 224868041.347 TARGET_SUN_POSITION_VECTOR = (90383106.973 , 190134070.109 , 80373887.843 ) TARGET_SUN_VELOCITY_VECTOR = (-27.0100 , 8.4617 , 9.6191 ) TARGET_HELIOCENTRIC_DISTANCE = 225344253.287 SC_EARTH_POSITION_VECTOR = (119020067.997 , 52913218.155 , 21467981.102 ) DEEPIMPACT:SC_GEOCENTRIC_DISTANCE = 132009315.786 EARTH_TARGET_POSITION_VECTOR = (-119883773.220 , -53252228.000 , -21037040.305 ) EARTH_TARGET_VELOCITY_VECTOR = (-1.7372 , -13.6608 , -11.8722 ) TARGET_GEOCENTRIC_DISTANCE = 132855093.742 PHASE_ANGLE = 62.186 /***** PROCESSING_HISTORY_TEXT *****/ PROCESSING_HISTORY_TEXT = "RAW" OBJECT = HEADER BYTES = 37440 HEADER_TYPE = "FITS" INTERCHANGE_FORMAT = "BINARY" RECORDS = 13 DESCRIPTION = " FITS format defined in NASA/Science Office Standards Technology 100-1.0 " END_OBJECT = HEADER OBJECT = IMAGE LINE_SAMPLES = 512 LINES = 512 SAMPLE_BITS = 16 SAMPLE_TYPE = "MSB_INTEGER" AXIS_ORDER_TYPE = "FIRST_INDEX_FASTEST" LINE_DISPLAY_DIRECTION = "UP" SAMPLE_DISPLAY_DIRECTION = "RIGHT" OFFSET = 32768 UNIT = "DATA NUMBER" MINIMUM = 361 MAXIMUM = 5461 MEDIAN = 372.0 STANDARD_DEVIATION = 768.6 END_OBJECT = IMAGE --------------------------------- Page 38 --------------------------------- OBJECT = EXTENSION_QUALITY_HEADER BYTES = 2880 HEADER_TYPE = "FITS" INTERCHANGE_FORMAT = "BINARY" RECORDS = 1 DESCRIPTION = " This extension contains a quality map for the primary image array. Each of the one-byte pixels in this map is composed of eight bits. Each bit represents a specific characteristic about the corresponding pixel in the primary image array. For a raw image, only the bit for a missing data value is set (bit 1 below). The remaining 7 bits apply only to a calibrated image and are thus set to zero for a raw image. The bits are described below and are listed from the least-significant (0) to most-significant (7): 0 = Bad 1 = Data for this pixel was not received from the spacecraft or this pixel is one of the image header bytes. 2 = Despiked 3 = Interpolated 4 = Partially saturated 5 = Mostly saturated 6 = ADC saturated 7 = Ultra compressed " END_OBJECT = EXTENSION_QUALITY_HEADER OBJECT = EXTENSION_QUALITY_IMAGE LINE_SAMPLES = 512 LINES = 512 SAMPLE_BITS = 8 SAMPLE_TYPE = "MSB_UNSIGNED_INTEGER" AXIS_ORDER_TYPE = "FIRST_INDEX_FASTEST" LINE_DISPLAY_DIRECTION = "UP" SAMPLE_DISPLAY_DIRECTION = "RIGHT" END_OBJECT = EXTENSION_QUALITY_IMAGE END --------------------------------- Page 39 --------------------------------- 3.1.2 Science Level 3/4 (Calibrated) Visible CCD Data Product This is an example of a PDS label for reversible, calibrated HRIV FITS science image, in units of radiance (RADREV, not cleaned). Labels are identical for RAD (radiance units, cleaned) and I-over-F (unitless, cleaned) science images. Labels for reduced HRIV, MRI, and ITS navigation images are identical to the example below, except several keywords in the FITS header do not exist because the information was not included in the minimal image headers. PDS_VERSION_ID = PDS3 RECORD_TYPE = "FIXED_LENGTH" RECORD_BYTES = 2880 FILE_RECORDS = 841 ^HEADER = "HV0173628244_9000007_001_RR.FIT" ^IMAGE = ("HV0173628244_9000007_001_RR.FIT", 18) ^EXTENSION_QUALITY_HEADER = ("HV0173628244_9000007_001_RR.FIT", 383) ^EXTENSION_QUALITY_IMAGE = ("HV0173628244_9000007_001_RR.FIT", 384) ^EXTENSION_SNR_HEADER = ("HV0173628244_9000007_001_RR.FIT", 476) ^EXTENSION_SNR_IMAGE = ("HV0173628244_9000007_001_RR.FIT", 477) DATA_SET_ID = "DIF-C-HRIV-3/4-9P-ENCOUNTER-V2.0" INSTRUMENT_HOST_NAME = "DEEP IMPACT FLYBY SPACECRAFT" INSTRUMENT_HOST_ID = "DIF" INSTRUMENT_NAME = " DEEP IMPACT HIGH RESOLUTION INSTRUMENT - VISIBLE CCD" INSTRUMENT_ID = "HRIV" /***** PRODUCT INFORMATION *****/ PRODUCT_ID = "HV0173628244_9000007_001_RR_FIT" PRODUCT_NAME = " DI FLIGHT DATA, REDUCED HRIV, HV0173628244_9000007_001_RR.FIT" PRODUCT_CREATION_TIME = 2006-11-13T16:40:35 PRODUCT_TYPE = "RDR" /***** TIME INFORMATION *****/ START_TIME = 2005-07-03T02:06:54.263 STOP_TIME = 2005-07-03T02:06:55.763 DEEPIMPACT:IMAGE_MID_TIME = 2005-07-03T02:06:55.013 START_JULIAN_DATE_VALUE = 2453554.5881280 STOP_JULIAN_DATE_VALUE = 2453554.5881454 MID_JULIAN_DATE_VALUE = 2453554.5881367 SPACECRAFT_CLOCK_START_COUNT = "1/0173628243.143" SPACECRAFT_CLOCK_STOP_COUNT = "1/0173628245.015" DEEPIMPACT:SPACECRAFT_CLOCK_MID_COUNT = "1/0173628244.079" DEEPIMPACT:TIME_FROM_IMPACT_VALUE = -99459.252 EARTH_RECEIVED_TIME = 2005-07-03T02:14:15.348 /***** OBSERVATION INFORMATION *****/ MISSION_PHASE_NAME = "9P ENCOUNTER" DEEPIMPACT:MISSION_ACTIVITY_TYPE = "CONTINUOUS COMET IMAGING" OBSERVATION_TYPE = "EIGHT-FILTER SET EVERY HOUR" TARGET_NAME = "9P/TEMPEL 1 (1867 G1)" INSTRUMENT_MODE_ID = 2 DEEPIMPACT:COMPRESSED_IMAGE_VALUE = "UNCOMPRESSED" COMPRESSOR_ID = "N/A" OBSERVATION_ID = 9000007 IMAGE_NUMBER = 1 DEEPIMPACT:COMMANDED_IMAGE_COUNT = 1 FILTER_NUMBER = 6 FILTER_NAME = "CLEAR6" CENTER_FILTER_WAVELENGTH = 650 DEEPIMPACT:MINIMUM_EXPOSURE_DURATION = 3.500 DEEPIMPACT:COMMANDED_EXPOSURE_DURATION = 1497.000 DEEPIMPACT:INTERFRAME_DELAY_DURATION = 0.000 --------------------------------- Page 40 --------------------------------- DEEPIMPACT:INTEGRATION_DURATION = 1500.500 INSTRUMENT_TEMPERATURE = ( 301.085 , 301.220 , 293.094 , 299.235 , 271.769 , 169.922 , 137.828 , 136.716 , 129.781 , 136.879 , 84.172 ) INSTRUMENT_TEMPERATURE_POINT = ( "INSTRUMENT CONTROLLER PROCESSING BOARD", "CCD SIGNAL PROCESSING BOARD", "IR SIGNAL PROCESSING BOARD", "LVPS SIGNAL PROCESSING BOARD", "CCD PREAMP BOX", "CCD ON-CHIP SENSOR", "PRISMS", "PRIMARY MIRROR", "SECONDARY MIRROR", "SPECTRAL IMAGING MODULE COVER", "IR FPA ON-CHIP SENSOR" ) INSTRUMENT_VOLTAGE = ( 1.206 , 1.213 , 1.206 , 1.217 , 5.123 , 5.120 , 5.113 , 5.105 , 5.027 , -4.985 , 5.002 , -9.187 , 0.245 , 0.742 , 3.407 , "UNK" ) INSTRUMENT_VOLTAGE_POINT = ( "CCD OFFSET FROM ADC REF QUAD A", "CCD OFFSET FROM ADC REF QUAD B", "CCD OFFSET FROM ADC REF QUAD C", "CCD OFFSET FROM ADC REF QUAD D", "CCD OUTPUT AMP DRAIN QUAD A", "CCD OUTPUT AMP DRAIN QUAD B", "CCD OUTPUT AMP DRAIN QUAD C", "CCD OUTPUT AMP DRAIN QUAD D", "CCD SERIAL CLOCK POSITIVE", "CCD SERIAL CLOCK NEGATIVE", "CCD PARALLEL CLOCK POSITIVE", "CCD PARALLEL CLOCK NEGATIVE", "IR RESET", "IR SUBSTRATE", "IR BIASGATE", "IR CALIB LAMP" ) /***** IMAGE INFORMATION *****/ HORIZONTAL_PIXEL_SCALE = 2048.707 VERTICAL_PIXEL_SCALE = 2048.707 /***** GEOMETRY PARAMETERS *****/ NOTE = " Earth Mean Equator and Vernal Equinox J2000 is the inertial reference system used to specify observational geometry. Geometric parameters were calculated using version 1.0 of the Deep Impact SPICE data set archived in PDS." SPICE_FILE_NAME = ("NAIFSTARNAMES_2005321_V01.TPC", "IMPACTTOI_0006.TPC", "NAIF0008.TLS", "PCK00008.TPC", "DI_TEMPEL1_V01.TPC",