Zobrazeno 1 - 10
of 20
pro vyhledávání: '"Roger Tokars"'
Publikováno v:
Frontiers in Marine Science, Vol 8 (2021)
The states of Michigan and Ohio issued shutdown orders in mid-March 2020 in an attempt to slow the spread of the coronavirus (COVID-19), resulting in widespread disruption to economic and human activity. This study, which was commissioned by NASA hea
Externí odkaz:
https://doaj.org/article/9239b193d64b47018a49edfafda52183
Autor:
Bo Yang, Song Shu, Min Xu, Hongxing Liu, Shujie Wang, Richard A. Beck, John D. Lekki, Molly K. Reif, Roger Tokars, Erich Emery, Robert C. Anderson, Yang Liu
Publikováno v:
IEEE Transactions on Geoscience and Remote Sensing. 60:1-16
In previous studies, empirical models have been widely used to map water quality parameters for inland waters using remotely sensed imagery. Due to the complex optical properties of inland waters, empirical models often have limited performances and
Autor:
John D. Lekki, Yang Liu, Bo Yang, Robert C. Anderson, Richard A. Beck, Richard Johansen, Min Xu, Teresa Benko, Erich Emery, Hongxing Liu, Molly K. Reif, Song Shu, Roger Tokars
Publikováno v:
IEEE Transactions on Geoscience and Remote Sensing. 57:4758-4774
Various empirical algorithms have been developed to retrieve chlorophyll-a (Chl-a) from multispectral and hyperspectral images as a proxy variable for algal blooms in inland waters. In most previous studies, a single empirical model (global model) wa
Autor:
John Lekki, Robert C. Anderson, Michael J. Sayers, Reid W. Sawtell, Robert A. Shuchman, Karl R. Bosse, Roger Tokars
Publikováno v:
Journal of Great Lakes Research. 45:596-608
The hyperspectral imaging system (HSI) developed by the NASA Glenn Research Center was used from 2015-2017 to collect high spatial resolution data over Lake Erie and the Ohio River. Paired with a vicarious correction approach implemented by the Michi
Autor:
Stephen Schiller, Jeffrey C. Luvall, Robert C. Anderson, Joseph D. Ortiz, Michael J. Sayers, Richard Becker, Dulci M. Avouris, Robert A. Shuchman, Roger Tokars, John D. Lekki
Publikováno v:
Journal of Great Lakes Research. 45:522-535
The Kent State University (KSU) spectral decomposition method provides information about the spectral signals present in multispectral and hyperspectral images. Pre-processing steps that enhance signal to noise ratio (SNR) by 7.37–19.04 times, enab
Autor:
Reid W. Sawtell, Michael J. Sayers, Robert C. Anderson, John Lekki, Karl R. Bosse, Roger Tokars, Eric Deutsch
Publikováno v:
Journal of Great Lakes Research. 45:434-443
Harmful algal blooms (HABs) have become a major health and environmental concern in the Great Lakes. In 2014, severe HABs prompted the State of Ohio to request NASA Glenn Research Center (GRC) to assist with monitoring algal blooms in Lake Erie. The
Autor:
Roger Tokars, Catharine L. R. McGhan, Richard P. Stumpf, Min Xu, Ou Ma, Hongxing Liu, Carol Tolbert, Erich Emery, Thomas Black, Molly K. Reif, John D. Lekki, Richard Johansen, Richard A. Beck
Publikováno v:
Lake and Reservoir Management. 35:193-207
Johansen RA, Beck R, Stumpf R, Lekki J, Tokars R, Tolbert C, McGhan C, Black T, Ma O, Xu M, Liu H, Reif M, Emery E. 2019. HABSat-1: assessing the feasibility of using CubeSats for the detec...
Autor:
Pushkar Pandit, John J. Pouch, Nathaniel C. Wilson, Tony D. Roberts, Ian R. Nemitz, Skyler Baugher, Sarah A. Tedder, Bertram Floyd, John D. Lekki, Evan J. Katz, Roger Tokars, Brian E. Vyhnalek
Publikováno v:
Broadband Access Communication Technologies XII.
Entangled photon pairs are created by a system consisting of a 1064 nm pump diode laser that is fiber coupled to a high generation rate photon pair source. The source is a dual element periodically poled potassium titanyl phosphate (KTP) waveguide th
Autor:
Roger Tokars, Richard Becker, Joseph D. Ortiz, Robert A. Shuchman, Robert C. Anderson, John D. Lekki, Dulcinea Avouris, Stephen Schiller, Michael J. Sayers, Jeffrey C. Luvall
Publikováno v:
Frontiers in Marine Science, Vol 4 (2017)
Analysis of visible remote sensing data research requires removing atmospheric effects by conversion from radiance to at-surface reflectance. This conversion can be achieved through theoretical radiative transfer models, which yield good results when
Publikováno v:
Geological Society of America Abstracts with Programs.