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Wolfe R.E.,NASA | Nishihama M.,Sigma Space Corporation | Lin G.,Innovim | Tewari K.P.,Innovim | Montano E.,Sigma Space Corporation
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2012

The VIIRS instrument was launched on the NASA/NOAA Suomi NPP satellite in October 2011. This instrument is the first of a series of VIIRS instruments meant to continue the operational and long-term measurements of NASA, NOAA and DOD heritage instruments such as the MODIS instruments on the NASA EOS Terra and Aqua satellites and other. The VIIRS Sensor Data Record product recently achieved Beta Maturity in geometric and radiometric performance after the initial on-orbit instrument characterization and calibration. In this paper, we compare MODIS and VIIRS instrument's geometric characteristics and geolocation accuracy. This VIIRS geometric characterization is on-going and the product to be much more mature by the end of the year. At this time, the MODIS and VIIRS instruments have different but comparable geometric performance and that the VIIRS geometric characteristics will enable it to fulfill the mission objectives. © 2012 IEEE.

Timofeyeva-Livezey M.,National Oceanic and Atmospheric Administration | Horsfall F.,National Oceanic and Atmospheric Administration | Hollingshead A.,Innovim | Meyers J.,National Oceanic and Atmospheric Administration | Dupigny-Giroux L.-A.,University of Vermont
Bulletin of the American Meteorological Society | Year: 2015

The National Oceanic and Atmospheric Administration (NOAA) has responded to the increased demand for local climate information by developing the Local Climate Analysis Tool (LCAT). The tool provides rapid responses to climate questions that historically required an extensive data search, research on appropriate analysis techniques, and complex graphics packages. LCAT offers easy and efficient access to scientifically sound analytical capabilities and trusted climate data. Results obtained from LCAT provide relevant climate information to local technical users, decision makers, and educators that will help build a healthy nation and create resilient communities. To ensure that LCAT responds to the articulated needs for local climate studies, a team of representatives from the NWS field offices routinely collects and ranks needs for capabilities to be incorporated into LCAT. The team also helps to design the LCAT user interface and provides training on the tool's features, methods, and usability. The LCAT framework offers analyses of climate change impacts, climate variability impacts, and correlation.

Chang C.-I.,University of Maryland Baltimore County | Chang C.-I.,National Chung Hsing University | Wu C.-C.,Innovim | Lo C.-S.,National formosa University | Chang M.-L.,National Taipei University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2010

The simplex growing algorithm (SGA) was recently developed as an alternative to the N-finder algorithm (N-FINDR) and shown to be a promising endmember extraction technique. This paper further extends the SGA to a versatile real-time (RT) processing algorithm, referred to as RT SGA, which can effectively address the following four major issues arising in the practical implementation for N-FINDR: 1) use of random initial endmembers which causes inconsistent final results; 2) high computational complexity which results from an exhaustive search for finding all endmembers simultaneously; 3) requirement of dimensionality reduction because of large data volumes; and 4) lack of RT capability. In addition to the aforementioned advantages, the proposed RT SGA can also be implemented by various criteria in endmember extraction other than the maximum simplex volume. © 2009 IEEE.

Olsen M.A.,Morgan State University | Olsen M.A.,NASA | Douglass A.R.,NASA | Kaplan T.B.,Innovim
Journal of Geophysical Research: Atmospheres | Year: 2013

The extratropical stratosphere-troposphere exchange (STE) of ozone from 2005 to 2010 is estimated by combining Microwave Limb Sounder ozone observations and MERRA reanalysis meteorological fields in an established direct diagnostic framework. The multiyear mean ozone STE is 275 Tg yr-1 and 214 Tg yr-1 in the Northern and Southern Hemispheres, respectively. The year-to-year variability is greater in the Northern Hemisphere, where the difference between the highest and the lowest annual flux is 15% of the multiyear mean compared with 6% in the Southern Hemisphere. Variability of lower stratospheric ozone and variability of the net mass flux both contribute to interannual variability in the Northern Hemisphere ozone flux. The flux across the extratropical 380K surface determines the amount of flux across the extratropical tropopause, and the greatest seasonal variability of the 380K ozone flux occurs in the late winter/early spring, around the time of greatest flux. Both the mass flux and the ozone mixing ratios on the 380K surface show recurring spatial patterns, but interannual variability of these quantities and their alignment contribute to the ozone flux variability. The spatial and temporal variability are not well represented when zonal and/or monthly mean fields are used to calculate the ozone STE, although this results in a small high bias of the seasonal amplitude and annual magnitude. If the climatological variability over these 6 years is representative, the estimated number of years required to detect a 2-3% decade-1 trend in ozone STE using this diagnostic is 35-39 years. © 2012. American Geophysical Union.

Wu X.,The Center for Satellite Applications and Research | Liu Q.,University of Maryland University College | Zeng J.,The Center for Satellite Applications and Research | Grotenhuis M.,The Center for Satellite Applications and Research | And 18 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2014

This paper evaluates the first 15 months of the Ozone Mapping and Profiler Suite (OMPS) Sensor Data Record (SDR) acquired by the nadir sensors and processed by the National Oceanic and Atmospheric Administration Interface Data Processing Segment. The evaluation consists of an inter-comparison with a similar satellite instrument, an analysis using a radiative transfer model, and an assessment of product stability. This is in addition to the evaluation of sensor calibration and the Environment Data Record product that are also reported in this Special Issue. All these are parts of synergetic effort to provide comprehensive assessment at every level of the products to ensure its quality. It is found that the OMPS nadir SDR quality is satisfactory for the current Provisional maturity. Methods used in the evaluation are being further refined, developed, and expanded, in collaboration with international community through the Global Space-based Inter-Calibration System, to support the upcoming long-term monitoring. ©2014. American Geophysical Union. All Rights Reserved.

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