======================================================================
Data Set Overview:
======================================================================

The data from the Rosetta Navigation Camera (NavCam) was extracted by
Bernhard Geiger and Michael Kueppers; the data set was constructed and
submitted by Colin Archibald on behalf of the Planetary Science
Archives (PSA).

The data have been observed and measured during the lead up to and
flyby of the asteroid 2867 Steins.  The data arises from the time
period 4 August 2008 and 5 September 2008 (closest approach on 5
September 2008).

All images in this data set are raw and uncalibrated data taken using
the imaging mode.  The data set contains images resolved using both
NavCams onboard the Rosetta S/C and the DATA directory is organised
to reflect this with two sub directories:
 - CAM1
 - CAM2

Each NavCam has seven different operational modes, however, only
data acquired under the IMAGING MODE will be present in the data
sets released and so only this mode shall be presented in any detail.
A point of note: IMAGING MODE can be operated under the other
available modes.

The MODE DESCRIPTION table below outlines the details of the
IMAGING MODE.

======================================================================
Mode Description:
======================================================================

IMAGING MODE:

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|     SUB MODE      | FRAME RATE |   WINDOW SIZE  | INTEGRATION TIME |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| IDLE              |    1 s     |      N/A       |        N/A       |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| COVER POSITIONING |   0.8 s    |      N/A       |        N/A       |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| IMAGE ACQUISITION |    35 s    |   20 x 20 px   |       10 ms      |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| IMAGE ACQUISITION |    35 s    | 1024 x 1024 px |       30  s      |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The IDLE sub mode allows for the window size of the CCD to be set up
before the IMAGE ACQUISITION mode begins operation.  The sizes and
times shown here for the IMAGING MODE are the lowest and upper bounds
there are hundreds more possibilities for WINDOW SIZE, and hence read
out time, under this sub mode.

Generally the rule is that if a window size is one full row (1024 px)
spanned over one pixel then the readout time will be 4.1 ms, thus the
full window (1024 x 1024 px) will have a total readout time of 4.2 s
(including transfer time of 1.3 ms for the image to be received to
the Solid State Mass Memory (SSMM)).

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Filename Convention:
======================================================================

The filenaming convention for all data levels is given by:

           __.
              ROS     CAM1    YYYYMMDDThhmmss    IMG
                      CAM2                       LBL
                                                (JPG)

Examples:
        ROS_CAM1_20100530T224504.IMG
        ROS_CAM1_20100530T224504.LBL
       (ROS_CAM1_20100530T224504.JPG)
        ROS_CAM2_20100620T231651.IMG
        ROS_CAM2_20100620T231651.LBL
       (ROS_CAM2_20100620T231651.JPG)

(In the case of the BROWSE directory)

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Geometry Information - Coordinate System:
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The geometry item SC_SUN_POSITION_VECTOR provided in the label of the
data product is relative to the ECLIPJ2000 frame. This reference frame
is built up by  Ecliptic Coordinates related to Equinox of Epoch
J2000.

Orientation:
 - X: Pointing from SUN to Vernal Equinox            
 - Y: perpendicular to X in Ecliptic Plane           
 - Z: Perpendicular to Ecliptic plane, pointing north.

The items:
 - RIGHT_ASCENSION   
 - DECLINATION       
are given in the PLANETOCENTRIC coordinate system.

All these geometry parameters are computed at time t = START_TIME.

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N/A