Project Title:
Imaging Radiometer for the Characterization of Boundary Layer Phenomena
92-1-02.07-0204 NAS01-19906
Imaging Radiometer for the Characterization of
Boundary Layer Phenomena
SSG, Inc.
150 Bear Hill Road
Waltham, MA 02154
Wallace K. Wong (617-890-0204)
Abstract:
The critical boundary layer condition between laminar and
turbulent flow over an airfoil area is indicated by extremely
small temperature differences (a noise-equivalent T of .1øC). The
complexity of the measurement problem is dramatically increased by
the 100 K ambient temperature and the need for a non-perturbing
technique. The core innovation is the exploitation of wide-
spectral band, cryogenic optical systems, and commercial, mosaic
plane focal array technologies in a unique, calibratable imaging
radiometer operating at 100 K. The focal plane array (FPA) is an
Si:Ga array with response to 18 æm which uses the long wavelength
radiation emitted by the cold surface. Phase I trade studies will
determine the optimum combination of spatial resolution, noise-
equivalent T, field of regard, and instrument size with the fixed
FPA configuration to best meet the sensor requirements. Upon their
completion, a preliminary optical design and a conceptual system
design will be performed, and a prototype optical system will be
developed. The system will provide the desired sensitivity
increase in airfoil testing and permit improved design of high-
speed aircraft and high-altitude vehicles. The concept is
applicable to any remote, high sensitivity, wide-spectral
radiometric measurement application operating over a wide range of
ambient temperatures.
Potential Commercial Application:
Potential Commercial Applications: The concept applies to
calibrated radiometric measurement applications, including design
of commercial aircraft and space vehicles, transfer calibration of
radiometric standards and sensors, and testing of high
sensitivity, low background focal plane arrays.
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