Author_Institution :
NASA/GSFC, Greenbelt, MD, USA
Abstract :
NASA has a current and next-generation requirement to collect high-quality in-situ data for the vicarious calibration of ocean color satellite sensors and to validate the algorithms that use the remotely sensed observations. As aquatic remote sensing shifts from the legacy perspective of optically simplistic open oceans toward next-generation observations of myriad optically complex water masses in the coastal zone and polar regions, instrument deployments from small platforms are a necessity. In response to this need, NASA funded the development of a new approach to measuring light: the microradiometer. A microra-diometer consists of a photodetector, preamplifier with controllable gain, high resolution (24 bit) analog-to-digital converter (ADC), microprocessor, and an addressable digital port. The microradiometer interface electronics allows sensors that were not traditionally considered “radiometers” to be treated in like fashion by the system electronics, greatly simplifying the addition of other detectors, such as temperature, water pressure, platform angle, or even supply voltage and current. This latter feature inherently leads to the concept of hybrid microradiometers, and because microradiometers simply plug onto the aggregator board stack, unique configurations of hybrid sensing and detecting capabilities are readily imagined.
Keywords :
analogue-digital conversion; calibration; ocean temperature; oceanographic equipment; photodetectors; preamplifiers; radiometers; remote sensing; underwater optics; ADC; NASA; addressable digital port; aggregator board stack; algorithm validation; analog-to-digital converter; aquatic remote sensing shifts; capability detection; coastal zone; controllable gain; current detector; current generation requirement; high resolution; high-quality in-situ data; hybrid instrument building blocks; hybrid microradiometer concept; instrument deployments; microprocessor; microradiometer interface electronics; myriad optically complex water masses; new measuring light approach development; next-generation observations; next-generation ocean color instruments; next-generation requirement; ocean color satellite sensor vicarious calibration; optically simplistic open ocean legacy perspective; photodetector; platform angle detector; polar regions; preamplifier; remotely sensed observations; small platforms; supply voltage detector; system electronics; temperature detector; unique hybrid sensing configurations; water pressure detector; Oceans; Optical imaging; Optical sensors; Radiometers; Sea measurements; apparent optical properties (AOPs); hybrid instruments; irradiance; microradiometer; photodetector; profiles; radiance; radiometer;