DATA_SET_DESCRIPTION |
Required Reading
================
The format of all Alice data are described in detail by the EAICD
document located in the /DOCUMENT directory. In addition, the
Rosetta Alice logbook file, RA_LOGBOOK_NNN.ASC, also located in
the DOCUMENT directory provides observational details such as
observation target, commanded exposure time, etc., for all Alice
data. The Alice team strongly recommends reading this
documentation before using the data.
Data Set Overview
=================
This data set contains calibrated data acquired by the Rosetta
Orbiter ALICE UV Spectrometer during the second earth swing-by
phase of the Rosetta mission, which occurred September 13, 2007 to
December 13, 2007. Observations of calibration targets, the earth
and the moon were made during this mission phase. A detailed listing
of all Alice observations is given in the observation log file located
in the DOCUMENT directory.
Processing
==========
The data in this data set are calibrated, CODMAC Level 3 data. As
such, corrections for detector dead time, dark counts, flatfield,
and effective area have generally been applied. The primary FITS
header contains a list of which corrections have been applied to
that file. There are some significant discrepancies in the
absolute calibration that will be corrected in a subsequent
data delivery when the calibration is better understood.
Data
====
The data are in FITS format and text format. Each FITS file
has a detached PDS label so that they can be read either by
FITS or PDS tools. A detailed description of the data format
is given in the ALICE EAICD document located in the DOCUMENT
directory of this data set.
Ancillary Data
==============
No ancillary data included in this data set.
Coordinate System
=================
The geometry items SC_SUN_POSITION_VECTOR,
SC_TARGET_POSITION_VECTOR and SC_TARGET_VELOCITY_VECTOR
provided in the label of the data product are relative to the
Earth Mean Equator frame of J2000.
SUB_SPACECRAFT_LATITUDE, SUB_SPACECRAFT_LONGITUDE are
given in the PLANETOGRAPHIC coordinate system. These parameters
are computed at time t=START_TIME. Distances are given in km,
angles in degrees.
Software
========
All FITS readers should be able to successfully read the data.
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