Wszystkie pola: remote sensing algorithm - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Spectra of light absorption by phytoplankton pigments in the Baltic; conclusions to be drawn from a Gaussian analysis of empirical data
Autorzy:: Ficek, D.
Kaczmarek, S.
Ston-Egiert, J.
Wozniak, B.
Majchrowski, R.
Dera, J.
Powiązania:: https://bibliotekanauki.pl/articles/47835.pdf
Data publikacji:: 2004
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: phytoplankton pigment
remote sensing algorithm
Baltic Sea
Gaussian analysis
light absorption
Opis:: Analysed by differential spectroscopy, 1208 empirical spectra of light absorption apl(λ) by Baltic phytoplankton were spectrally decomposed into 26 elementary Gaussian component bands. At the same time the composition and concentrations of each of the 5 main groups of pigments (chlorophylls a, chlorophylls b, chlorophylls c, photosynthetic carotenoids and photoprotecting carotenoids) were analysed in 782 samples by HPLC. Inspection of the correlations between the intensities of the 26 elementary absorption bands and the concentrations of the pigment groups resulted in given elementary bands being attributed to particular pigment groups and the spectra of the mass-specific absorption coefficients established for these pigment groups. Moreover, balancing the absorption effects due to these 5 pigment groups against the overall absorption spectra of phytoplankton suggested the presence of a sixth group of pigments, as yet unidentified (UP), undetected by HPLC. Apr eliminary mathematical description of the spectral absorption properties of these UP was established. Like some forms of phycobilins, these pigments are strong absorbers in the 450–650 nm spectral region. The packaging effect of pigments in Baltic phytoplankton was analysed statistically, then correlated with the concentration of chlorophyll a in Baltic water. As a result, a Baltic version of the algorithm of light absorption by phytoplankton could be developed. This algorithm can be applied to estimate overall phytoplankton absorption spectra and their components due to the various groups of pigments from a knowledge of their concentrations in Baltic water.
Źródło:: Oceanologia; 2004, 46, 4
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Modelling light and photosynthesis in the marine environment
Autorzy:: Wozniak, B.
Dera, J.
Ficek, D.
Majchrowski, R.
Ostrowska, M.
Kaczmarek, S.
Powiązania:: https://bibliotekanauki.pl/articles/47660.pdf
Data publikacji:: 2003
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: primary production
pigment
underwater irradiance
marine environment
quantum yield
remote sensing algorithm
bio-optical modelling
photoacclimation
phytoplankton
chromatic acclimation
light absorption
photosynthesis
Opis:: The overriding and far-reaching aim of our work has been to achieve a good understanding of the processes of light interaction with phytoplankton in the sea and to develop an innovative physical model of photosynthesis in the marine environment,suita ble for the remote sensing of marine primary production. Unlike previous models,the present one takes greater account of the complexity of the physiological processes in phytoplankton. We have focused in particular on photophysiological processes,whic h are governed directly or indirectly by light energy,or in which light, besides the nutrient content in and the temperature of seawater,is one of the principal limiting factors. To achieve this aim we have carried out comprehensive statistical analyses of the natural variability of the main photophysiological properties of phytoplankton and their links with the principal abiotic factors in the sea. These analyses have made use of extensive empirical data gathered in a wide diversity of seas and oceans by Polish and Russian teams as well as by joint Polish-Russian expeditions. Data sets available on the Internet have also been applied. As a result,a set of more or less complex,semi-empir ical models of light-stimulated processes occurring in marine phytoplankton cells has been developed. The trophic type of sea, photo-acclimation and the production of photoprotecting carotenoids,c hromatic acclimation and the production of various forms of chlorophyll-antennas and photosynthetic carotenoids,cell adaptation by the package effect, light absorption, photosynthesis, photoinhibition,the fluorescence effect,a nd the activation of PS2 centres are all considered in the models. These take into account not only the influence of light,but also, indirectly,tha t of the vertical mixing of water; in the case of photosynthesis,the quantum yield has been also formulated as being dependent on the nutrient concentrations and the temperature of seawater. The bio-optical spectral models of irradiance transmittance in case 1 oceanic waters and case 2 Baltic waters,dev eloped earlier,a lso are described in this paper. The development of the models presented here is not yet complete and they all need continual improvement. Nevertheless,w e have used them on a preliminary basis for calculating various photosynthetic characteristics at different depths in the sea,su ch as the concentration of chlorophyll and other pigments, and primary production. The practical algorithm we have constructed allows the vertical distribution of these characteristics to be determined from three input data: chlorophyll a concentration,irradiance, and temperature at the sea surface. Since all three data can be measured remotely,ou r algorithm can be applied as the ‘marine part’ of the remote sensing algorithms used for detecting marine photosynthesis.
Źródło:: Oceanologia; 2003, 45, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Algorithm for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 1: Mathematical apparatus
Autorzy:: Wozniak, B.
Krezel, A.
Darecki, M.
Wozniak, S.B.
Majchrowski, R.
Ostrowska, M.
Kozlowski, L.
Ficek, D.
Olszewski, J.
Dera, J.
Powiązania:: https://bibliotekanauki.pl/articles/47484.pdf
Data publikacji:: 2008
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: light-photosynthesis model
algorithm
chlorophyll
mathematical apparatus
temperature
primary production
Baltic ecosystem
remote sensing
Opis:: This article is the first of two papers on the remote sensing methods of monitoring the Baltic ecosystem, developed by our team. Earlier, we had produced a series of detailed mathematical models and statistical regularities describing the transport of solar radiation in the atmosphere-sea system, the absorption of this radiation in the water and its utilisation in a variety of processes, most importantly in the photosynthesis occurring in phytoplankton cells, as a source of energy for the functioning of marine ecosystems. The comprehensive DESAMBEM algorithm, presented in this paper, is a synthesis of these models and regularities. This algorithm enables the abiotic properties of the environment as well as the state and the functioning of the Baltic ecosystem to be assessed on the basis of available satellite data. It can be used to determine a good number of these properties: the sea surface temperature, the natural irradiance of the sea surface, the spectral and spatial distributions of solar radiation energy in the water, the surface concentrations and vertical distributions of chlorophyll a and other phytoplankton pigments in this sea, the radiation energy absorbed by phytoplankton, the quantum efficiency of photosynthesis and the primary production of organic matter. On the basis of these directly determined properties, other characteristics of processes taking place in the Baltic ecosystem can be estimated indirectly. Part 1 of this series of articles deals with the detailed mathematical apparatus of the DESAMBEM algorithm. Part 2 will discuss its practical applicability in the satellite monitoring of the sea and will provide an assessment of the accuracy of such remote sensing methods in the monitoring of the Baltic ecosystem (see Darecki et al. 2008 – this issue).
Źródło:: Oceanologia; 2008, 50, 4; 451-508
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Testing the performance of empirical remote sensing algorithms in the Baltic Sea waters with modelled and in situ reflectance data
Autorzy:: Ligi, M.
Kutser, T.
Kallio, K.
Attila, J.
Koponen, S.
Paavel, B.
Soomets, T.
Reinart, A.
Powiązania:: https://bibliotekanauki.pl/articles/48045.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: remote sensing
algorithm
Baltic Sea
coastal water
chlorophyll a
optical property
phytoplankton assemblage
water reflectance
Opis:: Remote sensing studies published up to now show that the performance of empirical (band-ratio type) algorithms in different parts of the Baltic Sea is highly variable. Best performing algorithms are different in the different regions of the Baltic Sea. Moreover, there is indication that the algorithms have to be seasonal as the optical properties of phytoplankton assemblages dominating in spring and summer are different. We modelled 15,600 reflectance spectra using HydroLight radiative transfer model to test 58 previously published empirical algorithms. 7200 of the spectra were modelled using specific inherent optical properties (SIOPs) of the open parts of the Baltic Sea in summer and 8400 with SIOPs of spring season. Concentration range of chlorophyll-a, coloured dissolved organic matter (CDOM) and suspended matter used in the model simulations were based on the actually measured values available in literature. For each optically active constituent we added one concentration below actually measured minimum and one concentration above the actually measured maximum value in order to test the performance of the algorithms in wider range. 77 in situ reflectance spectra from rocky (Sweden) and sandy (Estonia, Latvia) coastal areas were used to evaluate the performance of the algorithms also in coastal waters. Seasonal differences in the algorithm performance were confirmed but we found also algorithms that can be used in both spring and summer conditions. The algorithms that use bands available on OLCI, launched in February 2016, are highlighted as this sensor will be available for Baltic Sea monitoring for coming decades.
Źródło:: Oceanologia; 2017, 59, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Algorithms for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 2: Empirical validation
Autorzy:: Darecki, M.
Ficek, D.
Krezel, A.
Ostrowska, M.
Majchrowski, R.
Wozniak, S.B.
Bradtke, K.
Dera, J.
Wozniak, B.
Powiązania:: https://bibliotekanauki.pl/articles/47590.pdf
Data publikacji:: 2008
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: light-photosynthesis model
algorithm
chlorophyll
ocean colour
temperature
marine ecosystem
monitoring
empirical validation
primary production
Baltic ecosystem
remote sensing
Opis:: This paper is the second of two articles on the methodology of the remote sensing of the Baltic ecosystem. In Part 1 the authors presented the set of DESAMBEM algorithms for determining the major parameters of this ecosystem on the basis of satellite data (see Woźniak et al. 2008 – this issue). That article discussed in detail the mathematical apparatus of the algorithms. Part 2 presents the effects of the practical application of the algorithms and their validation, the latter based on satellite maps of selected Baltic ecosystem parameters: the distributions of the sea surface temperature (SST), the Photosynthetically Available Radiation (PAR) at the sea surface, the surface concentrations of chlorophyll a and the total primary production of organic matter. Particular emphasis was laid on analysing the precision of estimates of these and other parameters of the Baltic ecosystem, determined by remote sensing methods. The errors in these estimates turned out to be relatively small; hence, the set of DESAMBEM algorithms should in the future be utilised as the foundation for the effective satellite monitoring of the state and functioning of the Baltic ecosystem.
Źródło:: Oceanologia; 2008, 50, 4; 509-538
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: SeaWiFS-derived products in the Baltic Sea: performance analysis of a simple atmospheric correction algorithm
Autorzy:: Bulgarelli, B.
Melin, F.
Zibordi, G.
Powiązania:: https://bibliotekanauki.pl/articles/47664.pdf
Data publikacji:: 2003
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: ocean colour
remote sensing
accuracy analysis
Baltic Sea
atmospheric correction
Opis:: The accuracyan alysis of an approximate atmospheric correction algorithm for the processing of SeaWiFS data has been investigated for the Baltic Sea. The analysis made use of theoretical radiances produced with the FEM radiative transfer code for representative atmosphere-water test cases. The studysho wed uncertainties in the determination of the aerosol optical thickness at 865 nm and of the ˚Angstr¨om exponent lower than ±5% and ±10%, respectively. These results were confirmed bythe analysis of 59 match-ups between satellite-derived and in situ measurements for a site located in the central Baltic. Because of the relativelyhig h yellow substance absorption, often combined with the slanted solar illumination, the retrieval of the water-leaving radiance in the blue part of the spectrum appeared to be highlyd egraded, to the extent that almost no correlation was found between retrieved and simulated values. Better results were obtained at the other wavelengths. The accuracyin the estimation of the remote sensing reflectance ratio R35 decreased with diminishing chlorophyll a concentration and increasing yellow substance absorption, ranging between ±7% and ±47%. The propagation of R35 uncertainties on chlorophyll a estimation was quantified. Keeping the same atmosphere-water conditions, the atmospheric correction scheme appeared sensitive to seasonal changes in the Sun zenith.
Źródło:: Oceanologia; 2003, 45, 4
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Comparison of primary productivity estimates in the Baltic Sea based on the DESAMBEM algorithm with estimates based on other similar algorithms
Autorzy:: Stramska, M.
Zuzewicz, A.
Powiązania:: https://bibliotekanauki.pl/articles/48944.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: ocean colour
satellite remote sensing
Baltic Sea
primary productivity
algorithm
marine ecosystem
chlorophyll concentration
sea surface temperature
photosynthetic active radiation
latitude
Źródło:: Oceanologia; 2013, 55, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: Algorytm automatycznego oszacowania zróżnicowania gatunkowego drzewostanu z wykorzystaniem zdjęć RGB koron drzew
Species diversity of forest stands estimation algorithm using RGB images of the tree crowns
Autorzy:: Kotlarz, J.
Kacprzak, M.
Powiązania:: https://bibliotekanauki.pl/articles/276150.pdf
Data publikacji:: 2017
Wydawca:: Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:: bioróżnorodność
algorytmika
PCA
teledetekcja
klasyfikacja
ISOCLASS
leśnictwo
biodiversity
algorithmic
remote sensing
classification
forestry
Opis:: Ocena różnorodności gatunkowej ekosystemów jest jednym z fundamentalnych działań mających na celu ochronę naturalnych siedlisk, ich zdrowotności i użyteczności dla człowieka. W artykule zaproponowany został algorytm oszacowania wskaźnika Shannona-Wienera różnorodności drzewostanów za pomocą analizy statystycznej (PCA) oraz klasyfikacji (ISOCLASS) zdjęć RGB. Wykonanie zdjęć nie wymaga stosowania drogiego sprzętu i przy zachowaniu odpowiednich warunków oświetleniowych może być użyteczne w bieżącym monitoringu drzewostanów. Z drugiej strony, wskaźniki różnorodności wymagają walidacji in-situ. Algorytm posłużył w sierpniu 2016 r. do oszacowania różnorodności drzew w rezerwacie “Młochowski Grąd”. Za pomocą aparatu fotograficznego zintegrowanego z telefonem Microsoft Lumia 550 pozyskano 24 zdjęcia koron drzew w sześciu wchodzących w skład rezerwatu wydzieleniach leśnych. W wydzieleniu o najwyższej różnorodności wynik otrzymany za pomocą algorytmu ze względu na brak możliwości objęcia na pojedynczych zdjęciach wszystkich obecnych w nim gatunków nie odzwierciedlił faktycznego zróżnicowania drzewostanu. W pięciu wydzieleniach otrzymane wyniki były zbieżne z danymi in-situ zawartymi w Banku Danych o Lasach (współczynnik korelacji Pearsona = 0,967).
Global measurement of ecosystems species diversity is one of the fundamental postulates in natural habitats healthiness and usefulness protection. In the article an algorithm to estimate the Shannon-Wiener forest stands biodiversity indicator has been proposed. The algorithm includes statistical analysis (PCA) and classification methodology (ISOCLASS) for simple RGB images. Getting RGB images does not require the use of expensive hardware. Taking into account the sunlight conditions RGB images can be useful in the continuous forest stands monitoring. In August 2016 an attempt was made to estimate the diversity of the trees in the “Młochowski Grad” nature reserve using proposed in this article algorithm. Using camera integrated with a Microsoft Lumia 550 smartphone 24 images of trees crowns were acquired in the all six reserve forest stands. In the one stand with the highest crowns diversity the algorithms result does not agree with Forest Data Bank in-situ estimation. In the other five stands the results were consistent with the data in the Forest Data Bank (Pearson correlation index = 0.967).
Źródło:: Pomiary Automatyka Robotyka; 2017, 21, 1; 63-70
1427-9126
Pojawia się w:: Pomiary Automatyka Robotyka
Dostawca treści:: Biblioteka Nauki