Search publications of the members of the Royal Belgian institute of natural Sciences
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Biostratigraphy of the Upper Devonian trigonirhynchiid brachiopods (Rhynchonellida) from Armenia
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Field Intercomparison of Radiometer Measurements for Ocean Colour Validation
- A field intercomparison was conducted at the Acqua Alta Oceanographic Tower (AAOT) in the northern Adriatic Sea, from 9 to 19 July 2018 to assess differences in the accuracy of in- and above-water radiometer measurements used for the validation of ocean colour products. Ten measurement systems were compared. Prior to the intercomparison, the absolute radiometric calibration of all sensors was carried out using the same standards and methods at the same reference laboratory. Measurements were performed under clear sky conditions, relatively low sun zenith angles, moderately low sea state and on the same deployment platform and frame (except in-water systems). The weighted average of five above-water measurements was used as baseline reference for comparisons. For downwelling irradiance ( E d ), there was generally good agreement between sensors with differences of <6\% for most of the sensors over the spectral range 400 nm–665 nm. One sensor exhibited a systematic bias, of up to 11\%, due to poor cosine response. For sky radiance ( L s k y ) the spectrally averaged difference between optical systems was <2.5\% with a root mean square error (RMS) <0.01 mWm−2 nm−1 sr−1. For total above-water upwelling radiance ( L t ), the difference was <3.5\% with an RMS <0.009 mWm−2 nm−1 sr−1. For remote-sensing reflectance ( R r s ), the differences between above-water TriOS RAMSES were <3.5\% and <2.5\% at 443 and 560 nm, respectively, and were <7.5\% for some systems at 665 nm. Seabird-Hyperspectral Surface Acquisition System (HyperSAS) sensors were on average within 3.5\% at 443 nm, 1\% at 560 nm, and 3\% at 665 nm. The differences between the weighted mean of the above-water and in-water systems was <15.8\% across visible bands. A sensitivity analysis showed that E d accounted for the largest fraction of the variance in R r s , which suggests that minimizing the errors arising from this measurement is the most important variable in reducing the inter-group differences in R r s . The differences may also be due, in part, to using five of the above-water systems as a reference. To avoid this, in situ normalized water-leaving radiance ( L w n ) was therefore compared to AERONET-OC SeaPRiSM L w n as an alternative reference measurement. For the TriOS-RAMSES and Seabird-HyperSAS sensors the differences were similar across the visible spectra with 4.7\% and 4.9\%, respectively. The difference between SeaPRiSM L w n and two in-water systems at blue, green and red bands was 11.8\%. This was partly due to temporal and spatial differences in sampling between the in-water and above-water systems and possibly due to uncertainties in instrument self-shading for one of the in-water measurements.
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Data Needs for Hyperspectral Detection of Algal Diversity Across the Globe
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Offshore wind farm artificial reefs affect ecosystem structure and functioning: A synthesis
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Minéralisation et genèse du gîte stratiforme de Ravandje (Iran central)
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Découverte d'anhydrite dans les formations anténamuriennes du sondage de Saint-Ghislain
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Anomalous radiocarbon dates from the early medieval cremation graves from Broechem (Flanders, Belgium): reservoir or old wood effects?
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Dark Ages woodland recovery and the expansion of beech. A study of land use changes and related woodland dynamics during the Roman to Medieval transition period in northern Belgium
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A comparative study of parasites in three latrines from Medieval and Renaissance Brussels, Belgium (14th–17th centuries)
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Wood use in early medieval weapon production
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Bypassing the Suess-effect: Age determination of charcoal kiln remains using OSL dating
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) The significance of palaeoecological indicators in reconstructing estuarine environments: A multi-proxy study of increased Middle Holocene tidal influence in the lower Scheldt river, N-Belgium
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Milieueffectenbeoordeling van de aanleg en exploitatie van een telecommunicatiekabel in het Belgische deel van de Noordzee – Mercator project
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Offshore wind farms as stepping stones for Non-indigenous species
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International Assessment of Priority Environmental Issues for Land Based and Offshore Wind Energy Development
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VERSLAG MEERDAAGSE EXCURSIE GEOLIM 2022, 16-17 september 2022
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Natuursteenonderzoek bij de archeologische opgraving in de Burchtzone
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Archeologische opgraving Noorderterras. Natuursteen in de depositie van ballaststeen en hergebruikte bouwmaterialen van de Burcht, Scheldekaaien/Noorderterras. Studie uitgevoerd in opdracht van de stadsdienst Archeologie, Onroerend Erfgoed Stad Antwerpen
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Spiegelhuis Zoutleeuw. Natuursteendecoratie in de voorgevel. Studie t.a.v. Jan Peeters, eigenaar
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Grondbemonstering. Noorderterras, archeologische opgraving, Mattestraat, spoor 55 (voor Stadsarcheologie Antwerpen)
