J
John F. Schalles
Researcher at Creighton University
Publications - 44
Citations - 2736
John F. Schalles is an academic researcher from Creighton University. The author has contributed to research in topics: Colored dissolved organic matter & Phytoplankton. The author has an hindex of 24, co-authored 41 publications receiving 2205 citations. Previous affiliations of John F. Schalles include Emory University & National Oceanic and Atmospheric Administration.
Papers
More filters
Journal ArticleDOI
Remote chlorophyll-a retrieval in turbid, productive estuaries : Chesapeake Bay case study
TL;DR: In this paper, a conceptual model containing reflectance in three spectral bands in the red and near infra-red range of the spectrum was suggested for retrieving chla concentrations in turbid productive waters; it was calibrated and validated in lakes and reservoirs in Nebraska and Iowa.
Journal ArticleDOI
Seamless retrievals of chlorophyll-a from Sentinel-2 (MSI) and Sentinel-3 (OLCI) in inland and coastal waters: A machine-learning approach
Nima Pahlevan,Brandon I Smith,John F. Schalles,Caren Binding,Zhigang Cao,Ronghua Ma,Krista Alikas,Kersti Kangro,Daniela Gurlin,Nguyen Thi Thu Ha,Bunkei Matsushita,Wesley J. Moses,Steven Greb,Moritz K. Lehmann,Michael Ondrusek,Natascha Oppelt,Richard P. Stumpf +16 more
TL;DR: In this paper, a machine-learning model, the Mixture Density Network (MDN), was proposed for consistent, cross-mission retrievals of near-surface concentration of chlorophyll-a (Chla) in various aquatic ecosystems with broad ranges of trophic levels.
Journal ArticleDOI
Optical types of inland and coastal waters
Evangelos Spyrakos,Ruth O'Donnell,Peter D. Hunter,Claire Miller,Marian Scott,Stefan G. H. Simis,Claire Neil,Claudio Clemente Faria Barbosa,Caren Binding,Shane Bradt,Mariano Bresciani,Giorgio Dall'Olmo,Claudia Giardino,Anatoly A. Gitelson,Tiit Kutser,Lin Li,Bunkei Matsushita,Victor Martinez-Vicente,Mark W. Matthews,Igor Ogashawara,Antonio Ruiz-Verdú,John F. Schalles,Emma Tebbs,Yunlin Zhang,Andrew N. Tyler +24 more
TL;DR: In this article, a comprehensive dataset from more than 250 aquatic systems, representing a wide range of conditions, was analyzed in order to develop a typology of optical water types (OWTs) for inland and coastal waters.
Journal ArticleDOI
ESTIMATION OF CHLOROPHYLL a FROM TIME SERIES MEASUREMENTS OF HIGH SPECTRAL RESOLUTION REFLECTANCE IN AN EUTROPHIC LAKE
TL;DR: An algorithm relating the height of the 700‐nm reflectance peak above a reference baseline between 670 and 850 nm to chlorophyll a was accurate and robust despite large variations in optical constituents caused by both strong seasonality in the algal system and short‐term variations in seston from wind‐induced sediment resuspension.
Journal Article
Remote measurement of algal chlorophyll in surface waters: The case for the first derivative of reflectance near 690 nm
TL;DR: In this article, hyperspectral signatures, in fhe visible and near-infrored, associated with two experiments conducted outdoors in large water tanks; one involving relatively low amounts of chlorophyll over a narrow range and a second involving relatively high amounts over a wide range.