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| = Data Receipt and Processing = == Data Processing == Most spacecraft mission data is typically divided into "levels" of processing and refinement. |
= Telemetry & Level 0 Data Processing = <<TableOfContents>> |
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| * "Raw" data is the basic telemetry transferred from the spacecraft to the ground station, packaged as a file, with only basic r/f integrity checks run, and no processing done to it. * Level Zero refers to the cleanest, time-ordered set of data for a given instrument or spacecraft. 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, 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. * Level One data is usually "unpacked" Level Zero data, generally in the cleanest state possible (barring significant, irreversible data alteration). This data is time-sequenced, quality-filtered, [need more information here] * Level Two data has been irrevocably filtered, flat-fielded, time-sequence-merged, Fourier-transformed or otherwise changed or cleaned up from Level 0ne in a way that is irreversible. Level Two data can be re-created from Level One data, but not one cannot create Level One data from Level Two data. [[BR]] |
* 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 * [[MOCServer|Accessing the server]] -- Information about accessing the MOC Product Server == Level 0 Processing == * JSOC Level Zero Software Functional Specification.<<BR>> http://hmi.stanford.edu/development/JSOC_Documents/Level-0-Documents/JSOC-LEVEL0-PROCESSING-FS.pdf * Level 0 Image Processing (HSB Telemetry) <<BR>> -- Includes Time and Data Quality computations * Level 0 Housekeeping Telemetry Processing <<BR>> -- "Merged" Housekeeping DRMS record creation <<BR>> -- "Averaged" Housekeeping DRMS record creation * Housekeeping Configuration File Data Retrieval, Build, and Release to JSOC's TBL_JSOC Directory <<BR>>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. [[LEV0HKConfig|Users Guide on HK Configuration Data Retrieval, Build, and Release]] * Production Data Archive (raw and level0) * Data Accounting |
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| [[BR]] Important subsections of data processing include: [[BR]] * DDS (aka High Speed Bus) Data Capture * Offsite Data Archive (raw) * MOC Data Product Server Data Retrieval * Level 0 HSB Telemetry (Image) Processing * Includes Time and Data Quality computations * Level 0 Housekeeping Telemetry Processing * "Merged" Housekeeping DRMS record creation * "Averaged" Housekeeping DRMS record creation * Production Data Achive (raw and level0) * Data Accounting * Level 0.5 Processing and DRMS record creation |
* [[Lev0.1Doc|Level 0.1 Data Processing]] * [[Lev0.3Doc|Level 0.3 Data Processing]] * [[Lev0.5Doc|Level 0.5 Data Processing ]] |
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| * Level 1.0 Filtergram Calibration * Removal of overscan/underscan rows & columns * Identification of corrupted pixels * Application of offset and gain correction * Calculation of image center and limb position The JSOC, for the AIA & HMI instruments, defines the processes of Level Zero data to be: 1. Telemetry Checking 1. APID Lookup 1. Image Reconstruction 1. Housekeeping Processing All of the Level Zero data is recorded in the JSOC DRMS (database). More information on Level Zero is contained in the JSOC Level Zero Software Functional Specification. View this document at this link for more details: http://hmi.stanford.edu/development/JSOC_Documents/Level-0-Documents/JSOC-LEVEL0-PROCESSING-FS.pdf === Who uses it? === Typically, mission operations personnel and instrument operators want to see Level Zero data. It is available usually within minutes of receipt and persons very familiar with instrument/spacecraft engineering specs can make the best use of it. All kinds of raw image data and housekeeping data are present, including many useful temperatures, voltages and positions. Those requiring the most immediate spacecraft images are sometimes also Level Zero data users, such as CISM (Center for Integrated Space Weather Modeling). === What is Level 0.X? === The JSOC team has further segregated Level Zero data by making intermediate processing steps between Level Zero and Level One. These include: * ~+'''[:Lev0.1Doc:Level 0.1]'''+~ * ~+'''[:Lev0.3Doc:Level 0.3/Level 0.5]'''+~ === MOC Product Server === * ~+'''[:MOCServer:Accessing the server]''' -- Information about accessing the MOC Product Server +~ |
* [[HKTelTimAve|Housekeeping Telemetry Time Averaging]] |
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