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Title: Stray light correction of the marine optical system,
Description: The Marine Optical System is a spectrograph-based sensor used on the Marine Optical Buoy for the vicarious calibration of ocean color satellite sensors. It is also deployed from ships in instruments used to develop bio-optical algorithms that relate the optical properties of the ocean to its biological content. In this work, an algorithm is applied to correct the response of the Marine Optical System for scattered, or improperly imaged, light in the system. The algorithm, based on the measured response of the system to a series of monochromatic excitation sources, reduces the effects of scattered light on the measured source by one to two orders of magnitude. Implications for the vicarious calibration of satellite ocean color sensors and the development of bio-optical algorithms are described. The algorithm is a one-dimensional point spread correction algorithm, generally applicable to nonimaging sensors, but can in principle be extended to higher dimensions for imaging systems. © 2009 American Meteorological Society., Cited By (since 1996):6, Oceanography, CODEN: JAOTE, , , Downloaded from: journals.ametsoc.org/doi/pdf/10.../2008JTECHO597.1 (16 June 2014).
Author: Feinholz, Flora, Yarbrough, Lykke, Brown, Johnson, Clark
Date: 2009-01-01T00:00:00Z

Title: The Marine Optical Buoy (MOBY) radiometric calibration and uncertainty budget for ocean color satellite sensor vicarious calibration,
Description: For the past decade, the Marine Optical Buoy (MOBY), an autonomous radiometric buoy stationed in the waters off Lanai, Hawaii, has been the primary in-water oceanic observatory for the vicarious calibration of U. S. satellite ocean color sensors, including the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate Resolution Imaging Spectrometer (MODIS) instruments on the National Aeronautics and Space Administration's (NASA's) Terra and Aqua satellites. The MOBY vicarious calibration of these sensors supports international efforts to develop a global, multi-year time series of consistently calibrated ocean color data products. A critical component of the MOBY program is establishing radiometric traceability to the International System of Units (SI) through standards provided by the U. S. National Institute of Standards and Technology (NIST). A detailed uncertainty budget is a core component of traceable metrology. We present the MOBY uncertainty budget for up-welling radiance and discuss approaches in new instrumentation to reduce the uncertainties in in situ water-leaving radiance measurements., Cited By (since 1996):10, Oceanography, Art. No.: 67441M, CODEN: PSISD, ,
Author: Brown, Flora, Feinholz, Yarbrough, Houlihan, Peters, Yong, Mueller, Johnson, Clark
Date: 2007-01-01T00:00:00Z

Title: Radiometric characterization and absolute calibration of the Marine Optical System (MOS) Bench Unit,
Description: The Marine Optical System (MOS) is a dual charge-coupled device (CCD)-based spectrograph system developed for in-water measurements of downwelling solar irradiance E d and upwelling radiance L u. These measurements are currently used in the calibration and validation of satellite ocean color measurement instruments such as the moderate resolution imaging spectroradiometer (MODIS) and the Sea-viewing Wide Field-of view Sensor (SeaWiFS). MOS was designed to be deployed from a ship for single measurements and also integrated into the Marine Optical Buoy (MOBY) for longer time series datasets. Measurements with the two spectrographs in the MOS systems can be compared in the spectral interval from about 580 to 630 nm. In this spectral range, they give different values for L u or E d at a common wavelength. To better understand the origin of this observation and the sources of uncertainty in the calibration of MOBY, an MOS bench unit was developed for detailed radiometric characterization and calibration measurements in a laboratory setting. In the work reported here, a novel calibration approach is described that uses a tunable laser-based, monochromatic, spatially uniform. Lambertian, large area integrating sphere source (ISS). Results are compared with those obtained by a conventional approach using a lamp-illuminated ISS. Differences in the MOS bench unit responsivity between the two calibration approaches were observed and attributed to stray light. A simple correction algorithm was developed for the lamp-illuminated ISS that greatly improves the agreement between the two techniques. Implications for water-leaving radiance measurements by MOS are discussed., Cited By (since 1996):2, CODEN: JAOTE, , , Downloaded from: journals.ametsoc.org/ (13 June 2014).
Author: Habauzit, Brown, Lykke, Johnson, Feinholz, Yarbrough, Clark
Date: 2003-01-01T00:00:00Z

Title: Ocean optics protocols for satellite ocean color semsor validation, revision 4, Volume VI: Special topics in ocean protocols and appendices,
Description: , , ,
Author: Mueller, Clark, Kuwahara, Lazin, Brown, Fargion, Yarbrough, Feinholz, Flora, Broenkow, Kim, Johnson, Yuen, Strutton, Dickey, Abbott, Letelier, Lewis, McLean, Chavez, Barnard, Morrison, Subramaniam, Manov, Zheng, Harding Jr., Barnes, Lykke
Date: 2003-01-01T00:00:00Z

Title: Simultaneous measurement of up-welling spectral radiance using a fiber-coupled CCD spectrograph,
Description: Determination of the water-leaving spectral radiance using in-water instrumentation requires measurements of the upwelling spectral radiance (L u) at several depths. If these measurements are separated in time, changes in the measurement conditions result in increased variance in the results. A prototype simultaneous multi-track system was developed to assess the potential reduction in the Type A uncertainty in single set, normalized water-leaving radiance achievable if the data were acquired simultaneously. The prototype system employed a spectrograph and multi-track fiber-coupled CCD-detector; in situ in-water tests were performed with the prototype system fiber-coupled to a small buoy. The experiments demonstrate the utility of multi-channel simultaneous data acquisition for in-water measurement applications. An example of the potential impact for tracking abrupt responsivity changes in satellite ocean color sensors using these types of instruments as well as for the satellite vicarious calibration is given., Cited By (since 1996):1, Oceanography, Art. No.: 66800J, CODEN: PSISD, ,
Author: Yarbrough, Flora, Feinholz, Houlihan, Kim, Brown, Johnson, Voss, Clark
Date: 2007-01-01T00:00:00Z

Title: Stray light correction algorithm for multichannel hyperspectral spectrographs,
Description: An algorithm is presented that corrects a multichannel fiber-coupled spectrograph for stray or scattered light within the system. The efficacy of the algorithm is evaluated based on a series of validation measurements of sources with different spectral distributions. This is the first application of a scattered-light correction algorithm to a multichannel hyperspectral spectrograph. The algorithm, based on characterization measurements using a tunable laser system, can be extended to correct for finite point-spread response in imaging systems. © 2012 Optical Society of America., Cited By (since 1996):1, Oceanography, CODEN: APOPA, ,
Author: Feinholz, Flora, Brown, Zong, Lykke, Yarbrough, Johnson, Clark
Date: 2012-01-01T00:00:00Z

Title: Stray-light correction algorithm for spectrographs,
Description: In this paper, we describe an algorithm to correct a spectrograph's response for stray light. Two recursion relations are developed: one to correct the system response when measuring broad-band calibration sources, and a second to correct the response when measuring sources of unknown radiance. The algorithm requires a detailed understanding of the effect of stray light in the spectrograph on the instrument's response. Using tunable laser sources, a dual spectrograph instrument designed to measure the up-welling radiance in the ocean was characterized for stray light. A stray-light correction algorithm was developed, based on the results of these measurements. The instrument's response was corrected for stray light, and the effects on measured up-welling in-water radiance were evaluated., Cited By (since 1996):27, Oceanography, CODEN: MTRGA, ,
Author: Brown, Johnson, Feinholz, Yarbrough, Flora, Lykke, Clark
Date: 2003-01-01T00:00:00Z