Data Set Overview
=================
This dataset contains raw and reduced near-infrared images of
comet 9P/Tempel 1, the target of the Deep Impact mission. Images
were obtained from UT July 2-9, 2005, before, during, and after
the Deep Impact encounter by M. Knight, R. Swaters, and N.
Samarasinha using the Simultaneous Quad Infrared Imaging Device
(SQIID) on the Kitt Peak National Observatory (KPNO) 2.1-m
telescope.

Observations were made simultaneously in J (1.1-1.402 microns), H
(1.535-1.809 microns), and K (1.95-2.30 microns). L band images
were not saved due to saturation of the detectors caused by the
high sky background in the summer. The calibration procedure and
photometric results are described in detail in the paper
'Ground-based visible and near-IR observations of Comet 9P/Tempel
1 during the Deep Impact encounter' by Knight et al. 2007.

The published light curve for this data set is being combined with
that of the optical data set collected on 2-5 July 2005 from
San Pedro Martir (DI/EAR-C-I0276-2/3-MARTIR15M-TMPL1-V1.0) and is
in preparation at the Small Bodies Node.

Processing
==========
Images were processed using the IRAF UPSQIID package. The UPSQIID
package is available for download at
http://www.noao.edu/kpno/sqiid/upsqiid.tar.
A guide to data reductions using UPSQIID is available at
http://www.noao.edu/kpno/sqiid/upsqiidpkg.html.
Both the UPSQIID IRAF package (UPSQIID.TAR) and the guide to
reductions (UPSQIIDPKG.*) are reproduced in this archive with
permission from NOAO.

A dark frame was created for each filter, exposure, and coaddition
combinition using the USQDARK routine. This incorporates both the
base current (bias) and a time-dependent current (dark). Flat
fields were constructed for each filter each night from standard
star fields and off source pointings using the USQFLAT routine.
Processed images in this archive were created by subtracting the
dark frame and dividing by the flat field frame.

Images were processed further for the photometric calculations in
Knight et al. 2007. This included correcting for non-linearity and
subtraction of a median background. The response of the SQIID
detectors is non-linear for large counts. In general this effect
is small enough to be ignored. If the user wishes to correct for
the non-linearity they should refer to the non-linearity section
(section 8) of the SQIID user's manual (SQIIDMANUAL.*).

The standard star field S791-C (RA = 13h17m29.6s, Dec =
-05d32m37s) from Persson et al. (1998) was selected for its
proximity to the comet in both RA and Dec throughout the run,
allowing standard star observations to be interspersed with
comet observations. The stars in the field were used to
calculate atmospheric extinction corrections and absolute flux
calibrations. For photometric calculations, additional standard
star photometry was obtained from 2MASS (Skrutskie et al. 2006). 
Magnitudes were calculated using a circular 3.5 arcsec radius
aperture (13 pixel radius).

Further discussion of the calibration and photometric results can
be found in Knight et al. 2007.


Data
====
This data set consists of a calibrated photometry table and plot,
1770 reduced images (1431 comet frames, 72 sky frames, and 267
standard star frames) and 2894 raw images (1124 dark frames
plus the same 1770 frames in the reduced archive). The reduced
images are supplied as flattened, bias and dark subtracted
two-dimensional FITS image files with headers produced by the
SQIID data acquisition software.

The geometric circumstances of the comet and the sky conditions
from Knight et al. 2007 are reproduced here.

UT Date  UT time  r      delta  comet    standard  conditions
(2005)   (h)      (AU)   (AU)   airmass  star airmass
                                range    range
----------------------------------------------------------------
July 2   5.1-5.3  1.506  0.884  1.8-2.0  none      partly cloudy
July 3   3.8-6.8  1.506  0.889  1.5-4.0  1.4-1.7   photometric
July 4   4.1-7.3  1.506  0.894  1.5-8.4  1.4-2.0   high sky
                                                   background
July 5   3.5-6.5  1.506  0.899  1.4-3.5  1.4-2.0   photometric
July 6   3.7-6.5  1.506  0.905  1.5-3.8  1.4-2.1   photometric
July 7   3.7-6.5  1.506  0.910  1.5-4.0  1.4-2.2   photometric
July 8   3.7-6.5  1.506  0.915  1.5-3.9  1.4-2.3   photometric
July 9   3.7-6.5  1.507  0.921  1.5-3.7  1.4-2.1   photometric

When displaying a FITS image from this data set, North is
approximately up and East is to the left.


Summary of included material
============================
Products
--------
RAW/N1/         : Raw images from July 2, 2005 (UT)
    N2/         : Raw images from July 3, 2005 (UT)
    N3/         : Raw images from July 4, 2005 (UT)
    N4/         : Raw images from July 5, 2005 (UT)
    N5/         : Raw images from July 6, 2005 (UT)
    N6/         : Raw images from July 7, 2005 (UT)
    N7/         : Raw images from July 8, 2005 (UT)
    N8/         : Raw images from July 9, 2005 (UT)

REDUCED/N1/     : Calibrated images from July 2, 2005 (UT)
        N2/     : Calibrated images from July 3, 2005 (UT)
        N3/     : Calibrated images from July 4, 2005 (UT)
        N4/     : Calibrated images from July 5, 2005 (UT)
        N5/     : Calibrated images from July 6, 2005 (UT)
        N6/     : Calibrated images from July 7, 2005 (UT)
        N7/     : Calibrated images from July 8, 2005 (UT)
        N8/     : Calibrated images from July 9, 2005 (UT)


Ancillary data
--------------
OBS_LOG.TXT         : Observing log
COMET_POS.TXT       : File of comet positions in each image
KPNO_MAGNITUDES.TAB : Table of KPNO near-IR magnitudes of 9P/Tempel 1
KPNO_PHOTOMETRY.*   : Plot of KPNO near-IR photometry of 9P/Tempel 1
SQIIDMANUAL.*       : SQIID user's manual (ASCII text and PDF)
SQIIDSUPPL.*        : SQIID user's manual supplement
                      (ASCII text and PDF)
UPSQIIDPKG.TXT      : IRAF UPSQIID data reduction package user's
                      manual
UPSQIID_SOFTWARE    : Directory of IRAF UPSQIID data
                      reduction package programs

Confidence Level Overview
=========================
Standard techniques were used for the reduction of the data and
are documented in Knight et al. 2007.

Images have not been corrected for the non-linearity of the CCD.
See section 8 of the SQIID user's manual (SQIIDMANUALDOC.*).for
more details.