Project Title:

Quantum-Well Cloud Sensor

92-1-08.04-7001                                                   NAS05-32441
Quantum-Well Cloud Sensor
Space Instruments, Inc.
4403 Manchester Avenue, Suite 203
Encinitas, CA  92024
James W. Hoffman                                     (619-944-7001)

Abstract:

     The radiation characteristics of clouds are important factors
in understanding the Earth's climate. Cloud properties in the
infrared region have not previously been well measured from space.
The quantum-well cloud sensor (QCS) is an innovative spaceborne
instrument for imaging clouds and measuring their thermal
brightness and bi-directional reflectance in selected long
wavelength spectral bands. It also provides stereo viewing of
clouds for altitude measurements. The QCS utilizes a GaAs,
quantum-well, infrared photodetector (QUIP) array. This detector
array has extremely good pixel-to-pixel uniformity and negligible
i/f noise, which is important for future geostationary sensors
that will use long signal integration times to compensate for
their narrow field of views. In contrast to doped-silicon and
HgCdTe arrays which are expensive, difficult to produce, and low
yielding, the QUIP arrays promise to be more easily and uniformly
producible and significantly less expensive. The anticipated
results of Phase I are a feasibility analysis and a conceptual
design for a complete instrument which could be built in Phase II
and flown on a get-away special on the shuttle.

Potential Commercial Application:

Potential Commercial Applications:  Due to the lower manufacturing
cost and negligible i/f noise of the QUIP detector array, the
quantum-well cloud sensor is intended to be the forerunner of a
line of commercial mid- and long-wavelength sensors.

                                     ***