Telemetry & Level 0 Data Processing
- Level Zero refers to the lowest level of accessible data for a given instrument or spacecraft. Telemetry Checking, APID (Application ID) Lookup, Housekeeping telemetry processing and Image Reconstruction are performed at this level. The only processing done is typically the removal of duplicate data points (due to multiple file sends or a solid state recorder overlap), the removal or minimal repair of bad r/f data, the sorting of the different APIDs, and the matching of the end of one packet to the beginning of the next. The images taken by an instrument are left "as is" - not manipulated, not flat-fielded nor otherwise calibrated. All of the Level Zero data is recorded in the JSOC DRMS (database). In principle the level-0 data could be converted back to telemetry formatted data and is thus redundant with it but is in a more easily usable form using standard data storage protocols. JSOC image data is stored in compressed FITS files. JSOC metadata is stored in DRMS records but may be exported in several standard protocols (e.g. as part of exported FITS format images or tab delimited text tables).
Telemetry access information
- DDS Data Capture (aka High Speed Bus)
- Offsite Data Archive (raw data)
- MOC Data Product Server Data Retrieval
Accessing the server -- Information about accessing the MOC Product Server
Level 0 Processing
JSOC Level Zero Software Functional Specification.
http://hmi.stanford.edu/development/JSOC_Documents/Level-0-Documents/JSOC-LEVEL0-PROCESSING-FS.pdf- Level 0 Image Processing (HSB Telemetry)
-- Includes Time and Data Quality computations - Level 0 Housekeeping Telemetry Processing
-- "Merged" Housekeeping DRMS record creation
-- "Averaged" Housekeeping DRMS record creation - Housekeeping Configuration File Data Retrieval, Build, and Release to JSOC's TBL_JSOC Directory
JSOC Level Zero Functional Specification describes this functionality in section 3.6. The url link to JSOC Level 0 Functional Specification is shown above in first bullet. Information on running scripts to get housekeeping configuration data, building neccessary data files for Level 0 Processing and checking in files to JSOC CVS system are discussed in the Users Guide at the following link. Users Guide on HK Configuration Data Retrieval, Build, and Release - Production Data Archive (raw and level0)
- Data Accounting
JSOC will also include sub-levels (e.g. Level 0.3, Level 1.5) to indicate various stages of processing. For example, Level 0.3 will represent less processing (and perhaps less information) than Level 0.5.
- Orbit information
- Pointing information