DATA_SET_DESCRIPTION |
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Data Set history:
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First version
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Data Set Overview:
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The data from the Rosetta Navigation Camera (NavCam) were calibrated by
Bernhard Geiger; the processing pipeline was implemented by Rafael Andres;
the data set was constructed and submitted by Diego Fraga Agudo on behalf
of the Planetary Science Archives (PSA).
The data were acquired between 2016-08-09 and 2016-09-02. The frequency of
navigation slots was one image every hour, with interruption by manoeuvre
slots and OSIRIS-WAC imaging. This resulted in 292 navigation images.
There was one lost navigation image and one image with lost rows, both due to
bad weather at the ground station.
The spacecraft was in elliptical orbits with a 20 degrees tilt with
respect to the terminator plane, i.e. the phase angle ranged between
70 and 110 degrees. The pericentre was gradually reduced and the
apocentre increased while maintaining a constant orbital period of 3 days:
13.7km, 7.5km, 13.7km, 6.7km, 14.4km, 6.0km, 15.1km, 5.5km,
15.5km, 5.0km, 15.9km, 4.6km, 16.2km, 4.4km, 16.4km.
All images in this data set are radiometrically calibrated data taken using
the imaging mode. The data set contains images using NavCam CAM1
onboard the Rosetta S/C. NavCam instrument contains a second identical camera
called CAM2 but this was used mainly as a backup and the few images taken with
it have not been calibrated and are not included in the Level 3 datasets.
The images can be found in the DATA/CAM1 directory.
For each image, the user can also find the FITS format of the
observation in the EXTRAS/CAM1 directory.
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Filename Convention:
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In DATA:
The filenaming convention for all data levels is given by:
__.
ROS CAM1 YYYYMMDDThhmmss C IMG
CAM2 Q LBL
Where X can be C, Q or be absent. It is present for level 3 data (C for image
and label file, Q for quality map). It is absent for level 2 products.
Examples:
ROS_CAM1_20160308T154502C.IMG
ROS_CAM1_20160308T154502Q.IMG
ROS_CAM1_20160308T154502C.LBL
In BROWSE:
The filenaming convention for all data levels is given by:
__C.
ROS CAM1 YYYYMMDDThhmmss PNG
CAM2 LBL
Examples:
ROS_CAM1_20160308T154502C.PNG
ROS_CAM1_20160308T154502C.LBL
In EXTRAS:
The filenaming convention for all data levels is given by:
__CF.
ROS CAM1 YYYYMMDDThhmmss FIT
CAM2 LBL
Where C indicates it is a calibrated image file and F indicates it is in FITS
format.
Examples:
ROS_CAM1_20160308T154502CF.FIT
ROS_CAM1_20160308T154502CF.LBL
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Geometry Information - Coordinate System:
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The label files include the following geometric variables:
- SC SUN POSITION VECTOR: The vector from the spacecraft to the Sun
in equatorial J2000 inertial frame.
- SC TARGET POSITION VECTOR: The vector from the spacecraft to the
centre of the comet nucleus in equatorial J2000 inertial frame.
- SC TARGET VELOCITY VECTOR: The spacecraft to comet nucleus velocity
vector in in equatorial J2000 inertial frame.
- TARGET CENTER DISTANCE: The distance between the spacecraft and the
comet nucleus centre. (Note that also for checkout and stellar
calibration images the comet nucleus distance is given here.)
- SUB SPACECRAFT LATITUDE and SUB SPACECRAFT LONGITUDE: The latitude
and longitude of the sub-spacecraft point derived from the Flight
Dynamics body-fixed reference frame implicitly specified by the
information provided in the comet attitude file CATT.
- RIGHT ASCENSION and DECLINATION: Right Ascension and Declination of
the camera boresight direction in equatorial J2000 inertial frame.
- CELESTIAL NORTH CLOCK ANGLE: The direction of celestial north at the
center of the image - measured from the upward direction,
clockwise to the direction toward celestial north.
- SOLAR ELONGATION: The angle between the line of sight of observation
and the direction of the Sun.
All geometric values are calculated for the time t = IMAGE TIME
(and not START TIME).
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CITATION_DESCRIPTION |
Geiger, B., Andres, R. and Fraga, D.,
ROSETTA-ORBITER 67P NAVCAM 3 ROSETTA EXTENSION 3 MTP033 V1.0,
RO-C-NAVCAM-3-EXT3-MTP033-V1.0,
ESA Planetary Science Archive and NASA Planetary Data System, 2020.
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