"Micro-CPI" (wherein "CPI" signifies "cloud-particle imager") is the name of a small, lightweight electronic camera that has been proposed for use in research on clouds. The Micro-CPI would be incorporated into a small autonomous or remotely piloted airplane of a type that is now used in meteorological research and that is capable of remaining aloft for times long enough (typically about 30 hours) to collect statistically significant sets of data.

According to a preliminary design, the Micro-CPI would have a mass <1.5 kg and would consume less than 7 W of electric power. It would acquire and digitize highresolution (3-µm-pixel) images of ice particles and water drops at a rate up to 1,000 particles (and/or drops) per second. The Micro-CPI incorporates a particle detection laser that triggers the camera imaging laser, and also counts and sizes very small (<1-µm) aerosol particles and cloud drops up to about 100 µm in diameter. The Micro-CPI could record data for an observation time of more than 30 hours and could operate autonomously.

Although a quantitative estimate of the cost of the Micro-CPI is not yet available, it has been projected that the cost would be low, relative to the costs of cameras of conventional design that could offer the same imaging capabilities. This is fortunate because there could be a potential need in the coming years to launch hundreds or even thousands of small uninhabited aircraft carrying cameras of Micro-CPI design as part of an effort to measure properties of clouds on a global scale. There are also potential applications in the measurement of drop-size distributions in sprays, especially in the agricultural and painting industries.

This work was done by Paul Lawson of SPEC Inc. for Goddard Space Flight Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Electronics/Computers category. GSC-14950-1