This data set description was provided by Stephanie McLaughlin and Dennis Wellnitz, University of Maryland, who participated in the ground calibration tests of the Deep Impact instruments.  Data Set Overview:  This data set contains image and temperature data acquired during the preflight thermal-vacuum test (TV4) of High Resolution Instrument's Infrared Spectrometer (HRII) and Visible CCD (HRIV) and the Medium Resolution Instrument's Visible CCD (MRI) for Deep Impact. The experiments performed during TV4 were designed by the Ball Aerospace team with input from the Deep Impact science team. TV4 was conducted by Don Hampton of Ball Aerospace. Several science team members were present at all times to assist with the experiments and perform real-time analysis of the data.  The main objective of TV4 was to obtain calibration data for all three instruments on the Flyby spacecraft at the 140K temperature range for the HRI optics, warmer than TV2 where the lowest nominal temperature was 130K. The warmer operating temperature of the IR focal plane array (FPA) caused bad pixels to bloom in the HRII instrument.  Also, during TV4, several calibration experiments were performed for the HRII instrument, which had a light-reduction filter inserted into the middle of the spectrometer's slit after TV2 when it was determined that the HRII instrument would overexpose the nucleus of the comet during encounter:  - Perform tests at the nominal operating temperatures of 130K for the HRI optics and 106K for the IR FPA. - Determine best focus at the operating temperatures. - Obtain flat fields from various blackbody sources to measure the response of the FPA at different wavelengths. - Determine the non-linearity of the FPA. - Activate the internal calibration lamp. - Check for stray light. - Check for spectral motion caused by motion of the HRIV filter wheel. - Check adjustments made to the FPA spectral and spatial registrations based on TV1 results. - Check the spatial and spectral dispersion of the FPA.  Also, during TV4, several calibration experiments were performed for the HRIV and MRI instruments:  - Check focus. - Check co-alignment and co-focus with the HRII instrument. - Check registration of the parallel overclock columns and the serial overclock rows. - Test the photo-response of the CCD by using several calibrated blackbody sources and obtain flats. - Measure dark current as the CCD cools. - Measure bias.  To meet these objectives, the entire instrument platform for the Flyby spacecraft was placed inside the Rambo thermal-vacuum chamber. A test bench was setup outside the chamber to direct light from an external source through the main window of the chamber. The chamber was also equipped with a side window made of Zinc-Selenide to simulate the window of the Ball 8 chamber that was used during TV2.  TV4 activities are summarized in the following chart.  Avg Temperatures(K) Date/(DOY) FPA Prism CCD Tests ---------- -------------------- --------------------------------- 2003-02-23 304 305 306 Warm functional tests of all 3 (054) instruments  2003-02-24 304 305 306 Warm functional tests of all 3 (055) instruments  2003-02-25 304 305 306 Warm functional tests of all 3 (056) instruments HRIV: Warm focus  2003-02-26 ~282 ~281 ~291 Begin cooldown; Functional tests (057) HRIV: Focus, Dark current MRI: Dark current  2003-02-27 ~242 ~240 ~253 Continue cooldown (058) HRII: Test IR delay procedure HRIV: Dark current MRI: Dark current, Linearity, Flats, Focus,  2003-02-28 ~150 ~166 ~185 Continue cooldown (059) HRIV: Dark current MRI: Dark current  2003-03-01 ~109 ~142 ~165 Continue cooldown (060) HRII: Test light-reduction filter, Dark current, Flats, Argon source HRIV: Bias, Darks MRI: Bias, Darks, Latent image, Internal stimulator, Focus  2003-03-02 ~106 ~140 ~170 Cold (061) HRII: Light-reduction filter tests HRIV: Flats, Ambient light, Bias MRI: Flats, Ambient light, Bias  2003-03-03 ~106 ~140 ~173 HRIV: Co-boresight with MRI, Focus (062) MRI: Focus, Flats, Alignment  2003-03-04 ~106 ~140 ~170 MRI: Focus, Flats, Alignment (063)  2003-03-05 ~106 ~140 ~172 HRII: Ambient light (064) HRIV: Focus, Latent image, Flats Shutter block test, Bias MRI: Imaging  2003-03-06 ~105 ~139 ~168 HRII: Calibration lamp, Argon and (065) Krypton sources, Co-focus with HRIV, Light-reduction filter tests, Flats, Ambient light, Darks HRIV: Internal stimulator, Bias, Flats MRI: Flats  2003-03-07 ~106 ~139 ~172 Encounter sequence for all 3 (066) instruments HRII: IR delay tests, Flats, CO, CH4, and N2 gas cells, Darks, Linearity, Boresight with respect to HRIV HRIV: HRII boresight  2003-03-08 ~104 ~139 ~168 No data taken (067)  2003-03-09 ~104 ~139 ~168 Encounter sequence for all 3 (068) instruments  2003-03-10 ~106 ~144 ~180 Encounter sequence for all 3 (069) instruments HRII: Image test targets MRI: Image test targets  2003-03-11 ~134 ~160 ~185 HRIV: Warm imaging (070) MRI: Focus  2003-03-12 ~241 ~244 ~254 MRI: Warm imaging (071)   For more information about the mission, the HRI and MRI instruments, and the anticipated flight data, see A'Hearn, et al. (2005) [AHEARNETAL2005], Hampton, et al. (2005) [HAMPTONETAL2005], and Klaasen, et al. (2005) [KLAASENETAL2005].  Parameters:  HRII -----  The HRII spectral image data are in units of raw data numbers. For TV4, all seven of the HRII's image modes were tested:  Image MinExp X-Size Y-Size #Images Mode# (sec) (pix) (pix) Output Binning Comments ----- ------ ------ ------ ------- ------- ---------------------- 1 2.862 512 256 1 2x2 2 1.432 512 126 1 2x2 3 0.717 512 64 1 2x2 4 2.861 1024 512 1 1x1 5 2.865 512 256 1 2x2 6 1.432 1024 512 2 1x1 Reset then data frame 7 2.864 1024 512 1 1x1 Memory check mode  In this table, MinExp is the frame-to-frame minimum exposure times, X-Size is spectral dimension and Y-Size is spatial dimension of the FPA. For all image modes except 6, the reset frame is automatically subtracted, on-chip, from the data frame and the result is output. For more information about the image modes, see Hampton, et. al (2005) [HAMPTONETAL2005].  HRIV/MRI --------  The HRIV and MRI image data are in units of raw data numbers. The following image modes were defined and tested during TV4:  Image MinExp X-Size Y-Size Mode# (ms) (pix) (pix) Binning Comments ----- ------ ------ ------ ------- ------------------------- 1 3.5 1024 1024 1x1 Shuttered 2 3.5 512 512 1x1 Shuttered 3 3.5 256 256 1x1 Shuttered 4 217.8 256 256 1x1 Not shuttered 5 3.5 128 128 1x1 Shuttered 6 98.4 128 128 1x1 Not shuttered 7 47.4 64 64 1x1 Not shuttered 8 47.4 64 64 1x1 Not shuttered,no overscan 9 3.5 1024 1024 1x1 Shuttered; diagnostic  In this table, MinExp is the minimum exposure time and the term shuttered means the light blocker in the HRIV or MRI instrument is always used (opened and closed). For all modes, additional exposure time can be commanded. For unshuttered modes, a delay time (duration to wait before the start of the CCD readout) can also be commanded. For more information about the image modes, see Hampton, et. al (2005) [HAMPTONETAL2005].  Please note that the results from TV2 indicated the need for additional image modes with shorter minimum exposure times. Four new image modes were defined and implemented for all of the Deep Impact CCDs after TV2.  Data:  Images ------  The data are in the form of FITS files with attached FITS headers and detached PDS labels. One data files contains one HRII, HRIV or MRI image. The fastest-varying axis is considered the X axis and the slowest-varying, the Y axis. TV4 data filenames have this format: Iyymmdd_hhmmss_sss_x.FIT where the 'yymmdd_hhmmss_sss' string the date, time and subseconds stamp provided by the ground-support computer when it stored the original data file. The clock on the ground-support computer was set to local Mountain time. The 'x' string is valued with 'A' for HRIV or MRI data, and 'B' for HRII data. After TV2, the ground-support computer was modified to store the reset and data frames for HRII image mode 6 into two separate data files with unique time stamps; the reset frame was store first, then the data frame.  For TV4, the ground-support computer stored data files in a native image format, called 'IMG'. The raw data numbers were 14-bit and and left justified. A 100-byte image header was pre-pended to each data array. The 'IMG' data were converted to FITS at the Deep Impact Science Data Center (SDC) at Cornell University, using algorithms developed by Ball Aerospace for testing of the instruments and to allow real-time analysis of data during thermal-vacuum tests. During the conversion, raw data numbers were right justified to give the actual, true data numbers. Data in the 100-byte image header are captured in the FITS header.  After TV2, the Field Programmable Gate Arrays (FPGA) for each of the CCDs was adjusted so that the columns of serial overclocks and several rows of parallel overclocks would be correctly located around the edges of the CCD array.  During TV4, the amplifier gains for the IR FPA were not correct. This caused the right side of the array (columns 513-1014) to have a bias about 2000 DN (data number) greater than the left side fo the array (columns 1-512). Amplifier gains were corrected after TV4.  It is important to note that the higher IR FPA temperature during TV4 (106K) caused bad pixels to bloom noticeably when compared to data from TV2, when IR FPA temperatures range was about 86-90K.  Instrument Temperatures -----------------------  The instrument temperatures found in the PDS labels were extracted from the temperature keywords in the FITS headers. During TV4, ground-support equipment correctly recorded temperatures in the image headers. As a check, temperatures of various components of the HRII/HRIV and MRI instruments were also recorded every 5 minutes by two thermister monitors (computers). Temperature data, in fixed-width ASCII table format, are available in the data directory. There is one table of HRII/HRIV temperatures and one table of MRI. Time stamps in the temperature file are are based on local Mountain time and are within several minutes of the time stamps in the FITS filenames. Temperatures found in the tables or the PDS labels can be used for analysis  It is important to note that the IR FPA temperatures recorded by the thermister monitor were adjusted by -3.26K before being stored in the temperature table. After thermal-vacuum 4 (TV4), Ball Aerospace personnel analyzed all IR FPA temperatures and determined the temperatures recorded by the monitor needed to be adjusted by -3.26K because the cable connected to this temperature point included about 18 inches of manganin wire which resulted in higher temperature measurements due to its higher electrical resistance.  .Ancillary Data:  The DOCUMENT directory provides the HRII/HRIV and MRI image logs recorded during TV4. The logs contain an entry for each image acquired during TV4 and include image parameters such as mode and experiment type. The logs include a brief description of each type of experiment performed during TV4 and a summary of the experiments performed on each test date.  The DOCUMENT directory also provides daily reports written by the test leaders and distributed to the test team and the science team. The reports describe in detail the test activities as well problems and successes encountered during TV4.  The DOCUMENT directory includes the local PDS data dictionary used to produce the labels as well as sample IDL code used to read and extract temperatures from the TV4 HRII/HRIV temperature table.  Media/Format:  This data set is released as a logical data volume.

1) The time stamp in the FITS filename can vary by several tens of seconds of the actual time the image was acquired.  2) The project elected store and archive MRI FITS images from flight with the sky orientation during the approach to Tempel 1: East is to the left and North is up. However, MRI FITS images from TV4 were stored in the engineering orientation with East to the right and North up. When comparing MRI FITS images from TV4 to those acquired during flight, a left-to-right flip about the y axis is required for the TV4 data.  3) The images in this archive were used extensively by the science team and Ball Aerospace engineers to verify the instruments were operating within requirements and to calibrate the instruments. These data were reviewed internally by the Deep Impact project before release to the planetary community.