MSTI-III is the third in the Miniature Sensor Iechno1o' Integration series of satellites originally
conceived of and developed by BMDO and now being conducted by the US Air Force1. As the name
implies, the MSTI . satellites are members of the class of satellites which have come to be known as
"smalisats" or, alternatively, as "lightsats". The satellite is tentatively planned for launch in early 1996
into a sun-synchronous orbit which will allow the satellite to revisit a given region at the same solar time,
that is, at the same solar illumination conditions.
Among the objectives ofthe MSTI-III mission is the characterization of the optical properties of clouds
in the mid-wavelength infrared (MWIR), short-wavelength-infrared (SWIR), and visible spectral regions as
a function of spectral band, latitude, season, cloud type, cloud altitude, and solar scattering geometry.
MSTI-III is planned to be operational for a minimum of one year to ensure the collection of a statistically
significant data base. MSTI-III will also image the EartWs limb and surface. Radiometric characterization
and calibration completed in Aug 1995 indicate that MSTI-III will provide high-spatial-resolution infrared
images with high signal-to-noise ratios, based upon the scene radiances predicted for the planned
measurement modes from existing models or estimated from empirical data.
The data-collection experiments planned for MSTI-III and the utility of the MSTI-III data base for the
validation and development of cloud, atmospheric, and surface radiance models are discussed.