This Small Business Innovation Research Phase I project has as its main objective the development of a solar telescope and detector capable of imaging heat flow inhomogeneities at the sun's photosphere, with uniform photometric response over all wavelengths between the ultraviolet and infrared. Such a Solar Bolometric Imager (SBI) would provide an innovative new tool for identifying mechanisms of long-term solar luminosity variation. These variations are of great interest in studies of climate fluctuation, an issue of central importance in Global Change studies. The opportunity for innovation arises from recent advances in uncooled, relatively high-definition (80,000 element) thermal arrays. The main aim in Phase I is to determine whether the spectral absorptance of these arrays can be modified by careful deposition of gold blacks, to provide uniform response over the wavelength range between 0.33( and about 2( containing most of the solar radiation that reaches the Earth's surface. If this can be achieved while retaining the detectivity and time constant of the array, an all-reflecting telescope to complete the design of the SBI will be designed in Phase I. The SBI will be constructed and operated for one year in Phase II, during the period of increasing solar activity in the forthcoming sunspot cycle 23. A successful ground-based SBI would form the basis for a space-borne SBI as an imaging complement to absolute radiometers used for measuring fluctuations in the total irradiance. Commercial applications of bolometric imaging with relatively high angular definition include remote sensing and industrial metrology (calibration of thermographic cameras, lighting design, combustion research and monitoring). A high definition, uncooled array with good response in the near-IR could also provide the focal plane for a convenient and inexpensive false color spectral imaging camera with many niche applications in biomedical imaging, process control and non-destructive testing.
