Atmos Composition Hydrology A-Train AIRS Modeling MAIRS Measures Precipitation

Product Summary

Data Set Short Name: UARSO3BS
Data Set Long Name: UARS Solar-Stellar Irradiance Comparison Experiment (SOLSTICE) Level 3BS
Data Set Version: 001
Platform: Upper Atmosphere Research Satellite
Sensor(s): Solar-Stellar Irradiance Comparison Experiment
Horizontal Resolution: ultraviolet spectral range from 119 to 420 nm x ultraviolet spectral range from 119 to 420 nm
Temporal Coverage: 1991-10-03 - 1999-12-31
Data Holdings Page: View
User's Guide: README.UARSO3BS.doc

 Product Description

The Solar-Stellar Irradiance Comparison Experiment (SOLSTICE) on
NASA's Upper Atmosphere Research Satellite (UARS) measured the energy
input to the upper atmosphere by observing the solar spectral
irradiance in the ultraviolet spectral range from 119 to 420 nm. The
SOLSTICE measured the full disk solar irradiance with high precision
and accuracy to follow short-term (minutes to hours),
intermediate-term (days to weeks), and long-term (11 year sunspot, and
22 year solar magnetic field cycles) variations in the solar output.

The SOLSTICE instrument is a three-channel ultraviolet spectrometer that
measures the magnitude of solar and spectral irradiance in the wavelength
range form 119 to 420 nm. The design of the instrument allows for observations
of both the sun and bright blue stars (whose spectra in the SOLSTICE spectral
range is assumed to be constant) using the same optics. The entrance and exit
slit sizes are varied, and different integration times are used to accommodate
the 5 to 8 order of magnitude difference between the brightnesses of the sun
and blue stars.

SOLSTICE is mounted to the two-axis Solar Stellar Pointing Platform
(SSPP) which can track objects to an accuracy of 1.5 arc minutes.
During the daylight portion of an orbit SOLSTICE is pointed at the
sun, and during the nighttime portion it is pointed toward blue stars.
One or more full spectral scans of the sun at the instrument
resolution is completed each orbit. Stellar scans require longer
integration times, and are only made at a few selected wave- lengths
throughout the spectral range, with typically one or two stars at one
or two wavelengths being observed each orbit.

Two SOLSTICE Level 3 data products are produced each day: Level 3AS,
and Level 3BS. The Level 3AS format is common to all UARS solar instruments.
The Level 3BS format is identical to the Level 3AS format, except that
instrument degradation is included in the 3BS data products.

SOLSTICE_L3AS_DAILY: These data products contain a single array
representing a daily mean solar spectrum. Each element in the array
is spaced at 1.0 nm intervals and centered on the half nm from 115 to
420 nm. The array elements have been normalized to an earth-sun
distance of 1 AU. Also produced, as Level 3AS parameters, are daily
average integrated intensities (Gaussian fits) or core/wing ratios
(Mg-II at 280 nm and Ca-II at 393 nm) for selected solar spectral

SOLSTICE_L3BS_DAILY: These data products are produced from the
corresponding Level 3AS data product, and a table (calibration file)
of instrument degradation function coefficients which have been
determined from selected bright blue stars. The time-degradation
function (which varies with wavelength) is applied to the Level 3AS
irradiance spectrum and the integrated irradiance of the selected
spectral emission features, but not to the core/wing ratios, to
produce the Level 3BS data products.

* NOTE: only SOLSTICE_L3BS_DAILY data are available from the GSFC DAAC.
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  • Last updated: May 11, 2011 04:08:07 GMT