A Review of Protocols for Fiducial Reference Measurements of Water-Leaving Radiance for Validation of Satellite Remote-Sensing Data over Water

This paper reviews the state of the art of protocols for measurement of water-leaving radiance in the context of fiducial reference measurements (FRM) of water reflectance for satellite validation. Measurement of water reflectance requires the measurement of water-leaving radiance and downwelling irradiance just above water. For the former there are four generic families of method, based on: (1) underwater radiometry at fixed depths; or (2) underwater radiometry with vertical profiling; or (3) above-water radiometry with skyglint correction; or (4) on-water radiometry with skylight blocked. Each method is described generically in the FRM context with reference to the measurement equation, documented implementations and the intra-method diversity of deployment platform and practice. Ideal measurement conditions are stated, practical recommendations are provided on best practice and guidelines for estimating the measurement uncertainty are provided for each protocol-related component of the measurement uncertainty budget. The state of the art for measurement of water-leaving radiance is summarized, future perspectives are outlined, and the question of which method is best adapted to various circumstances (water type, wavelength) is discussed. This review is based on practice and papers of the aquatic optics community for the validation of water reflectance estimated from satellite data but can be relevant also for other applications such as the development or validation of algorithms for remote-sensing estimation of water constituents including chlorophyll a concentration, inherent optical properties and related products

Avian Attractiveness to Vertically Polarized Light

It is well-known that many animal species can detect polarized light cues of water and water-like objects in the visible and ultraviolet range. However, studies investigating if birds can see polarized light in field-based settings are rare. Furthermore, no studies have yet been conducted to understand avian attractiveness to vertically polarized light, nor have studies considered other natural polarizers of light such as tree sap. I designed a choice-field experiment to investigate if birds can detect, and are attracted to vertically polarized light. First, I cut six pieces of clear vinyl into a foot by 54 inches. I painted each vinyl sheet with Black 3.0, advertised as the blackest paint in the world. Two treatments were wrapped around two trees similar in dbh (\u3c40 dbh) and close in distance (\u3c5 feet): one had shiny exposed, and the other matte, painted side, exposed. Suet feeders were hung directly below each treatment on both trees. Two remote cameras were placed on a fence post away from both tree (10 feet in fall; 6 feet in spring). The suet feeder height, camera distance, and the height of both vinyl stayed the same. These treatments were exposed to birds. A baseline study was conducted before installation of treatments to understand bird biases or preferences to one tree position over the other. I made conclusions about birds being able to see, and their attraction to, vertically polarized light by capturing and counting visitations from images, and comparing treatments’ bird visits over a designated period of time. My results revealed that birds are able to detect and are attracted to vertically polarized light, and use it to guide foraging behavior. Attraction to polarized light is dependent upon the location of the site, as well as the position (left or right tree), and certain species may play a role in these conclusions, though they do not overwhelm the data. The baseline study to treatment comparison reveals that any preferences to one position over the other were eliminated when treatments were added, and the polarized, shiny treatment had more of a signal than the matte treatment when each treatment were compared separately to the baseline. These results suggest a need to expand site-wise across various habitats to understand the effects of site location, to understand the effects of the positionality of treatments on different species of trees, and to understand how different species may have an effect on treatment visitation. Sap was imaged using a polarimeter to understand if natural Maple sap polarizes light compared to my polarized proxy for sap. My analyses reveal that natural Maple sap polarizes light, and this is strongest in the ultraviolet range. My treatments polarize a high degree of light in both the visible and ultraviolet range, making it an effective simulator of natural Maple sap. This exciting discovery gives insight on how birds may navigate a complex landscape according to polarized cues of that landscape (polarization of sap), and how they use these cues to facilitate their foraging behavior (eating sap)

Study of the Remote Measurement of Ocean Color Final Report, 28 Aug. 1967 - 28 Jan. 1968

Spacecraft instrument system specifications for remote measurement of ocean colo

Two facets of insect vision : polarization sensitivity and visual pigments

Summary The polarization pattern of the sky serves many insects as a reference for visual compass orientation. Chapter I specifies thresholds for the behavioral response to polarized light in field crickets (Gryllus campestris) under conditions mimicking those experienced by the animals in their natural habitat. Our results show that the polarization vision system of crickets is extremely sensitive and robust. Photoreceptors involved in the detection of polarized skylight are generally confined to a small part of the insect compound eye, the so-called dorsal rim area (DRA). In Chapter II, we construct a model for the sensory input to the polarization vision system of fruit flies (Drosophila melanogaster) and compare it with data from crickets, thus demonstrating the consequences of two opposite DRA designs for neuronal coding of orientation. Group-specific distinctions in the morphology of DRA ommatidia suggest that polarization vision evolved independently in several insect taxa. However, developmental findings indicate that DRA formation in distantly related species is initiated by homologous signaling pathways. We address the question of DRA ancestry in Chapter III where we report pilot experiments that failed to detect the same selector gene for DRA specification in two- spotted crickets (Gryllus bimaculatus) as previously identified in fruit flies. Polarization vision in crickets is mediated by blue receptors. Electrophysiological data imply that the respective visual pigment is exclusively found in the DRA. We have cloned four visual opsins of G. bimaculatus and investigated their phylogeny as well as their expression pattern in the compound eyes and the ocelli. Chapter IV reveals that the ocellar opsins diverged from those of the compound eyes and that regionalization in the cricket visual system is more complex than assumed earlier. Zusammenfassung Das Polarisationsmuster des Himmels dient vielen Insekten als Kompass zur visuellen Orientierung. Kapitel I beschäftigt sich mit der Reaktionsschwelle, die Feldgrillen (Gryllus campestris) auf polarisiertes Licht zeigen, wenn die Versuchsbedingungen die Verhältnisse im natürlichen Lebensraum der Tiere simulieren. Unsere Ergebnisse verdeutlichen, dass das Polarisationssehsystem von Grillen äußerst empfindlich und robust ist. Die Photorezeptoren, die an der Wahrnehmung von polarisiertem Himmelslicht beteiligt sind, findet man in der Regel nur in der so genannten dorsalen Randregion (DRA) des Komplexauges. In Kapitel II erstellen wir ein Modell für den sensorischen Eingang zum Polarisationssehsystem von Taufliegen (Drosophila melanogaster) und vergleichen es mit Daten von der Grille. Dabei demonstrieren wir die Konsequenzen, die zwei konträre DRA- Typen für die Kodierung der Körperorientierung im Gehirn haben. Taxon-spezifische Unterschiede in der Morphologie der DRA-Ommatidien deuten darauf hin, dass das Polarisationssehen in verschiedenen Insektengruppen unabhängig voneinander entstanden ist. Entwicklungsphysiologische Befunde hingegen lassen vermuten, dass die Ausbildung der DRA selbst in entfernt verwandten Arten durch homologe Signalwege ausgelöst wird. Wir befassen uns mit der Frage der DRA-Herkunft in Kapitel III, wo wir eine Pilotstudie vorstellen, in der das DRA-Selektorgen, das zuvor bei Fruchtfliegen identifiziert wurde, nicht bei Zweifleckgrillen (Gryllus bimaculatus) nachzuweisen war. Polarisationssehen wird bei Grillen durch blauempfindliche Photorezeptoren vermittelt. Elektrophysiologische Daten legen nahe, dass das zugehörige Sehpigment ausschließlich in der DRA vorkommt. Wir haben vier visuelle Opsine von G. bimaculatus kloniert und deren Abstammung sowie ihr Expressionsmuster in den Komplexaugen und Ocellen untersucht. Kapitel IV zeigt, dass sich die Opsine der Ocellen von denen der Komplexaugen unterscheiden und dass das visuelle System der Grille regional stärker spezialisiert ist als bisher angenommen.

Esparcimiento de Rayleigh

Light changesits path and the polarization state if it interacts with a medium whose particles are much smallerthanits wavelength. The phenomenon is most intense for colors of shorter wavelength. Consequently, for whitelight, the colors of the blue-violet region of the spectrum are most affected. In this article we presentseveralexperiments related to the polarization state of dispersed light through colloidal media.La luz modifica su trayectoria y su estado de polarización cuando interacciona con un medio cuyas partículastienen un tamaño mucho más pequeño que la longitud de onda. El fenómeno es más intenso para los colores demenor longitud de onda. De ahí que, en el caso de la luz blanca, se vean más afectados los colores de la regiónazul-violeta del espectro.En este artículo se presentan varios experimentos relacionados con el estado depolarización de la luz esparcida por medios coloidales.Palabras clave: Coloide; Esparcimiento; Longitud de onda; Polarización.Rayleigh scatteringLight changes its path and the polarization state if it interacts with a medium whose particles are much smaller than its wavelength. The phenomenon is most intense for colours of shorter wavelength. Consequently, for white light, the colours of the blue-violet region of the spectrum are most affected. Some of the experiments presented in this article are related to the polarization state of dispersed light through colloidal media.Keywords: Colloid; Scattering; Wavelength; Polarization

Rayleigh scattering

La luz modifica su trayectoria y su estado de polarización cuando interacciona con un medio cuyas partículas tienen un tamaño mucho más pequeño que la longitud de onda. El fenómeno es más intenso para los colores de menor longitud de onda. De ahí que, en el caso de la luz blanca, se vean más afectados los colores de la región azul-violeta del espectro. En este artículo se presentan varios experimentos relacionados con el estado de polarización de la luz esparcida por medios coloidales.Light changes its path and the polarization state if it interacts with a medium whose particles are much smaller than its wavelength. The phenomenon is most intense for colors of shorter wavelength. Consequently, for white light, the colors of the blue-violet region of the spectrum are most affected. In this article we presentseveral experiments related to the polarization state of dispersed light through colloidal media

Dedicated JPSS VIIRS Ocean Color Calibration/Validation Cruise

The NOAA/STAR ocean color team is focused on “end-to-end” production of high quality satellite ocean color products. In situ validation of satellite data is essential to produce the high quality, “fit for purpose” remotely sensed ocean color products that are required and expected by all NOAA line offices, as well as by external (both applied and research) users. In addition to serving the needs of its diverse users within the U.S., NOAA has an ever increasing role in supporting the international ocean color community and is actively engaged in the International Ocean-Colour Coordinating Group (IOCCG). The IOCCG, along with the Committee on Earth Observation Satellites (CEOS) Ocean Colour Radiometry Virtual Constellation (OCR-VC), is developing the International Network for Sensor Inter-comparison and Uncertainty assessment for Ocean Color Radiometry (INSITU-OCR). The INSITU-OCR has identified, amongst other issues, the crucial need for sustained in situ observations for product validation, with longterm measurement programs established and maintained beyond any individual mission. Recently, the NOAA/STAR Ocean Color Team has been making in situ validation measurements continually since the launch in fall 2011 of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (SNPP) platform, part of the U.S. Joint Polar Satellite System (JPSS) program. NOAA ship time for the purpose of ocean color validation, however, had never been allocated until the cruise described herein. As the institutional lead for this cruise, NOAA/STAR invited external collaborators based on scientific objectives and existing institutional collaborations. The invited collaborators are all acknowledged professionals in the ocean color remote sensing community. Most of the cruise principal investigators (PIs) are also PIs of the VIIRS Ocean Color Calibration and Validation (Cal/Val) team, including groups from Stennis Space Center/Naval Research Laboratory (SSC/NRL) and the University of Southern Mississippi (USM); City College of New York (CCNY); University of Massachusetts Boston (UMB); University of South Florida (USF); University of Miami (U. Miami); and, the National Institute of Standards and Technology (NIST). These Cal/Val PIs participated directly, sent qualified researchers from their labs/groups, or else contributed specific instruments or equipment. Some of the cruise PIs are not part of the NOAA VIIRS Ocean Color Cal/Val team but were chosen to complement and augment the strengths of the Cal/Val team participants. Outside investigator groups included NASA Goddard Space Flight Center (NASA/GSFC), Lamont-Doherty Earth Observatory at Columbia University (LDEO), and the Joint Research Centre of the European Commission (JRC). This report documents the November 2014 cruise off the U.S. East Coast aboard the NOAA Ship Nancy Foster. This cruise was the first dedicated ocean color validation cruise to be supported by the NOAA Office of Marine and Air Operations (OMAO). A second OMAO-supported cruise aboard the Nancy Foster is being planned for late 2015. We at NOAA/STAR are looking forward to continuing dedicated ocean color validation cruises, supported by OMAO on NOAA vessels, on an annual basis in support of JPSS VIIRS on SNPP, J-1, J-2 and other forthcoming satellite ocean color missions from the U.S as well as other countries. We also look forward to working with the U.S. and the international ocean community for improving our understanding of global ocean optical, biological, and biogeochemical properties.JRC.H.1-Water Resource

Down the Slant towards the Eye: Hopkins and Ecological Perception

This essay reads Gerard Manley Hopkins’s poetry for its “ecological perception”: a perceptual modality involving the dynamic interaction between human bodies and environmental givens or potentialities. Linking Hopkins’s syncretic ideas about perception to the psychologist J. J. Gibson’s account of our sensitivity to environmental “affordances,” the essay assesses three scales of ecological perception in Hopkins (arboreal, atmospheric, apocalyptic) and stresses the particular relevance of the intermediate (atmospheric) scale for our experience of environmental crisis. In “The Blessed Virgin compared to the Air we Breathe,” Hopkins recognizes the “teleconnections” bridging global systems and specific sites without remaining rooted to the local or bioregional (arboreal) or rushing to a vantage beyond planetary confines (apocalyptic)