One instrument would implement a synergistic combination of multispectral, multiangle, and polarimetric techniques.

A proposed remote-sensing instrument, to be carried aboard a spacecraft in orbit around the Earth, would gather data on the spatial distribution and radiative characteristics of tropospheric aerosols. These data are needed for better understanding of the natural and anthropogenic origins of aerosols, and of the effects of aerosols on climate and atmospheric chemistry.

The instrument would implement a synergistic combination of multispectral, multiangle, and polarimetric measurement techniques to increase the accuracies of aerosol-optical-depth and aerosol-particle-property characterizations beyond what is achievable by use of each technique by itself. Additional benefits expected to be realized by the specific novel combination of different measurement techniques in one instrument include the following:

• The instrument could make simultaneous measurements (described below) that are essential for determining the mesoscale variability of aerosols;
• The instrument would have a wideswath, high-resolution imaging capability for discerning clouds and for frequent global sampling; and
• The cost of building this instrument would be less than the cost of building separate instruments for the various measurements.

Features of the design and performance of the instrument would include spectral coverage from near ultraviolet to short-wave infrared, global spatial coverage within a few days, simultaneous intensity and polarimetric imaging at multiple view angles, kilometer to subkilometer spatial resolution, and measurement of the degree of linear polarization in one visible and one short-wave infrared spectral band.