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Accession Number N20130003506
Title OSPREy System Concept, Chapter 1.
Publication Date Jul 2012
Media Count 12p
Personal Author J. H. Morrow S. B. Hooker
Abstract The primary objective of the Optical Sensors for Planetary Radiant Energy (OSPREy) activity is to develop and deploy a new class of commercial radiometers to support existing and next-generation NASA ocean color satellites. An Enhanced Performance Instrument Class (EPIC) sensor is a hybridspectral device combining measurements of spectral irradiance and radiance from recently developed microradiometers with a commercially available hyperspectral spectrograph plus a pointing system. Over common parts of the spectrum, fixed-wavelength microradiometers and the spectrograph can be continuously intracompared to maintain stability and accuracy of the system. Radiance sensors have a nine-position filter-wheel assembly in line with the spectrograph fiber optics to permit hyperspectral polarimetric measurements (three polarized filters), direct-Sun viewing (neutral density filters), stray-light correction (395nm cut-on filter), and dark current measurements (opaque disk). Radiance sensors also have an integrated camera for locating the Sun and Moon (in lieu of a quadrant detector), as well as verifying the condition of all targets (cloud-free solar and lunar disks, cloud presence in sky data, and sea surface debris or foam detection). All sensors include thermal stability control to increase filter and detector stability and reduce drift. The field sensor suite includes shadowband accessories to the solar irradiance sensors, which are combined with radiance observations of the Sun, Moon, sea, and sky across a wide spectral range -- the UV, through the visible (VIS) and into the short-wave infrared (SWIR); 305-1,640nm is the full spectral range for radiance, as well as irradiance because of a new cosine collector design. The diversity of targets and measurement types provides an unprecedented number of near-simultaneous atmospheric and oceanic data products. This new sampling capability is expected to improve (a) the atmospheric correction of ocean color data; (b) the accuracy in satellite data products, particularly in optically complex (coastal) waters; and (c) the understanding of the interaction between the ocean and atmosphere. The combination of wide spectral and dynamic ranges with accurate pointing are also anticipated to have application to terrestrial observations.
Keywords Accuracy
Calibrating
Cameras
Component reliability
Dynamic range
Ocean surface
Oceanography
Polarimetry
Quality control
Radiance
Radiometers
Solar sensors
Spectrographs
Systems engineering
Systems integration
Tracking(Position)
Water color


 
Source Agency National Aeronautics and Space Administration
NTIS Subject Category 48 - Natural Resources & Earth Sciences
Corporate Author Goddard Space Flight Center, Greenbelt, MD.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1318
Contract Number N/A

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