Engineering Data

Engineering Data

General Information

Observing the Sun with SEE
XPS and EGS are components of the SEE instrument on the TIMED spacecraft. SEE has a one-axis (x) pointing platform that points the XPS and EGS towards the sun once per orbit with about 14.8 orbits/day. The sun then drifts through the perpendicular field-of-view direction (y) as the spacecraft travels along the orbital trajectory. About 20 10-second integrations are taken during each orbit.

Version and Revision Numbers
Filename convention: see__egs_L2_yyyydoy_ver_rv.ncdf where:

	  yyyydoy = 4-digit year and 3 digit day of year
	      ver = 3-digit data product version number
	       rv = 2-digit data product revision number

Example: see__egs_L2_2002365_005_02.ncdf is the file representing December 31, 2002 version 005 revision 02.

Revision numbers change whenever science data processing occurs. It is common for the EGS Level 2 data to experience several revisions. The highest revision number should always be used. First processing is always 01. Old revisions may be purged at any time.

Version numbers change when major software changes, major calibration changes, or major file format changes have occurred.


Use only data files with the highest version and revision numbers available. It is common for revision 01 files to be incomplete due to availability of essential telemetry and support files from the TIMED Mission Data Center. Old revisions of data files may be removed at any time. Higher versions always take precedence over older versions. Note that new versions usually involve significant changes in the data content and may be incompatible with data format structures from old versions.

Routine Science Data Processing Schedule

Initial processing (rev 01) for a day begins at 4 UT (52 hours after acquisition) and takes about 30 minutes. Second processing begins at 5 UT two days later. Third processing is performed after 30 days. New data product versions may have fewer revisions than old data product versions, since completeness is usually not an issue for reprocessing.

Other Measured Solar Irradiance Data at LASP

  • SME Data – Solar Irradiances from 115-300nm
  • UARS Data – SOLSTICE Solar Irradiances from 119-420nm
  • SORCE Data – Solar Irradiances from 0.1 – 30 nm and 119 nm – 2.5 microns plus Total Solar Irradiance
  • LISIRD – LASP Interactive Solar Irradiance Datacenter provides data for multiple LASP instruments

Solar Irradiance Reference Spectra

Solar Irradiance Models

  • TIME-GCM – HAO/NCAR Upper Atmosphere Model
  • SIP – Solar Irradiance Platform, Solar EUV Irradiance Model
  • NRLEUV (coming soon) – NRL Solar EUV Irradiance Model
  • SunRISE Irradiance Model (coming soon) – HAO/NCAR Solar UV Irradiance Model
  • EUV81 – Hinteregger et al. [1981] Solar VUV Irradiance Model
    sc21refw.dat – data file needed by EUV81
  • EUVAC – Richards et al. [1994] Solar EUV Irradiance Model

SEE Engineering

Engineering Data (internal use)

  • PDF files – daily engineering plots of temperatures, voltages, etc.
  • Text – brief listing of operations and diagnostic information

Operations Log and Utilities

Planning Tools

  • Planning Tools – this is a link for the APL Science Data Systems planning tools web page
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