Lucy L'LORRI Data Didymos Raw Collection

Data Set Overview
===============================================================================
This collection contains raw panchromatic (350 - 850 nm) images acquired by the
L'LORRI instrument during the Lucy Mission Didymos Encounter. Data
acquisition is described in Section 7 of the Lucy LLORRI DART Observation Archive
User’s Guide V2.0.  This document can be found in the the L'LORRI document collection.

Closest Approach occurred at 17:51:16 UT April 20, 2025 at a distance of 962 km. All tCA 
calculations (time of closest approach) are calculated from this date.


Version 1.0 of this collection was produced in July, 2023, which was before the 
final L'LORRI data processing pipeline was completed, as such version 1.0 products
should be used carefully. Data processing for these products is described in the
Lucy L'LORRI DART Observation Archive User’s Guide V2.0 found in the L'LORRI 
document collection. Caveats and limitations are given in this document.

Version 2.0 of this collection was produced in August 2025 with the production 
version of the L'LORRI data processing pipeline. This is the same pipeline that
produced the L'LORRI Dinkinesh data products. Data processing for these products
is described in the L'LORRI Software Interface Specification (lorri_sis) found
in the L'LORRI document collection. 

Difference between V1.0 and V2.0:

1) File-naming convention: e.g., lor_0717462911_02260_eng_01.fit ----> lor_0717462911_02260_00001_4x4_eng_03.fit
    - ObsID Count field has been added after the ObsID field
    - Image format field ("1x1", "4x4") has been added after the ObsID Count field

2) The keyword content of the primary FITS headers (and the PDS4 labels) has been significantly changed/expanded:
    - some formatting has changed, e.g., section separators have been added to improve readability
    - some of the names have been changed, e.g. "INSTRU" ----> "INSTRUME"
    - a lot of new keywords have been added, e.g.:
        - various flavors of exposure start/stop/mid times
        - product description keywords, e.g., processing location, software used, etc.
        - uplink planning information, e.g., command load, mission segment, SAP and visit names, etc.
        - greatly expanded set of geometrical information, states, pointings, rates, targets in FOV, etc.
        - full listing of the SPICE kernels used in the processing
        - expanded WCS section, with inclusion of SIP distortion model coefficients
        - full listings of the image header contents, both raw and converted values
        - section added for S/C-recorded HK, primarily temperature information
        
3) The "IMAGE HEADER" and "IMAGE DESCRIPTOR" extensions have been modified to give a true apples-to-apples
   comparison of the raw image header contents.  Before, the contents of the image descriptor packet had
   been broken out separately, which made the data arguably more user-friendly but less easy to compare to
   the actual image header.



Data Products 
===============================================================================
Products contained within this collection are .FITS images described in the
L'LORRI SIS document. Raw images are not radiometrically calibrated, and
instrument artifacts have not been removed. Image data units are in Digital
Number (DN).


Last Revision
2025-08-25