NASA categorizes Data Products based on a system of Levels starting with Level zero. A level zero data product is usually defined as representing raw, but cleaned spacecraft telemetry. Subsequent data levels represent successive levels of data processing involving calibration and the application of science algorithms. The SPP mission has defined five data levels that are described elsewhere.
After generation of the Level-1 FITS files, selected Level-3 products (mostly browse data) will also be generated in the IPP. Level-2 (calibrated) products will be generated onthe- fly by using routines in the Solarsoft library. The best-available calibration will be made available to users as it is obtained via Solarsoft. Most of the code in the IPP will be available in the Solarsoft library. This data product philosophy follows closely the SECCHI data model. The table below summarizes the various WISPR data products.
TheWISPR L1 quick-look data comprises two parts. Part 1 will be a subset of the images (such as subfields) sent down with low-latency to assist in planning selective downlink for other instruments and for planning WISPR observations for the next orbit. Part 2 of the quick-look data will be the remainder of the science telemetry, which is processed as it is played back. The L1 “Final” data set will replace the quick-look Part 2.
Level 2 data is calibrated data. Our experience suggests that it is more efficient to let the user generate the Level 2 data using standard software provided by the WISPR team as part of the Solarsoft library. Users are assured of having the latest calibration factors, and the operations team does not have to generate a new set of data every time calibrations are updated. A best and final Level 2 dataset will be provided when final calibrations are available, or after the end of the mission.
| Data Level |
Product Title | Contents | Format | Latency | Frequency |
|---|---|---|---|---|---|
| L1 | Level-1 quick-look | uncalibrated image data | FITS | T0+minutes | as received; track-dependent |
| L1 | Level-1 final | uncalibrated image data | FITS | T0 +7 days | per orbit |
| L3 | Browse images (quick-look and final) | uncalibrated binned images with background removed, and compressed | PNG, JPG |
L1+ minutes | same as L1 |
| L3 | Browse movies | browse images | MPG | L1+hours | same as L1 |
| L3 | Jmaps | time-elongation plots, uncalibrated | PNG | L1+hours | same as L1 |
| L3 | Syncronic or Carrington maps | heliospheric brightness at selected elongation angles | PNG | L1+hours | same as L1 |
| L2 | Level-2 | calibrated L1, user-generated | FITS | User-depended | as needed |
| L4 | CME masses | FITS | T0 +one year | Annually |
Data Archive
In addition, theWISPR team will provide the final instrument calibration and a complete best and final Level-2 calibrated data set from the entire mission to an appropriate NASA archive at the end of Phase F or the end of the extended mission. The WISPR data policy dictates completely open access to all data, including: Planning, Quick-look, and Final data products, the calibration data, and all procedures to calibrate and perform high-level processing of the data. NRL will maintain a web interface to a database of all science and housekeeping data that will permit users to search for data corresponding to time periods or events of interest using selected values from the image header, as well as to perform trend analysis of instrument housekeeping parameters such as temperatures and voltages. Validated science data will be distributed directly from NRL to requesters based on the results of a database query. Requests for larger amounts of data will be handled through the SPP Science Data Portal or the Virtual Solar Observatory (VSO).
In addition, theWISPR team will provide the final instrument calibration and a complete best and final Level-2 calibrated data set from the entire mission to an appropriate NASA archive at the end of Phase F or the end of the extended mission.
The WISPR data policy dictates completely open access to all data, including: Planning, Quick-look, and Final data products, the calibration data, and all procedures to calibrate and perform high-level processing of the data. NRL will maintain a web interface to a database of all science and housekeeping data that will permit users to search for data corresponding to time periods or events of interest using selected values from the image header, as well as to perform trend analysis of instrument housekeeping parameters such as temperatures and voltages. Validated science data will be distributed directly from NRL to requesters based on the results of a database query. Requests for larger amounts of data will be handled through the SPP Science Data Portal or the Virtual Solar Observatory (VSO).
Data Release Schedule
There will be two versions of WISPR processed science data: quick-look data produced immediately upon receipt of any image telemetry from the spacecraft (including a lowlatency "planning" subset), and final data incorporating any telemetry packets that may be missing or corrupted in the quick-look telemetry and that are later recovered. (See Sect. 4.4.) Quicklook L1 data may be used for mission operations planning purposes and will be made public as soon as it is processed. Final L1 data will replace the quicklook data and will be differentiated from the quicklook L1 data product in the FITS image header via the VERSION keyword. The Final L1 and resulting visualization data products will be (re-)generated after each orbit. These will be suitable for archiving and distribution. Both quick-look and final data will be processed in the same way and will have the same file formats.
Data Catalogues
The WISPR project will use an open source database program such as MYSQL, which is currently being used to manage the housekeeping and image header information on both SECCHI and LASCO. A web-based tool enables searches of the image header database with the ability to select FITS files for download using FTP to the user's computer. The table structures will be similar to the existing tables. For example, the existing IDL tools include the ability to extract any parameter(s) of interest and to generate plots against time or to correlate one parameter against another. It is our intention that the FITS header will mirror the SPASE catalog. To the extent that the required keywords are known, they will be incorporated into the image FITS headers.