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Wyszukujesz frazę "high resolution" wg kryterium: Temat


Tytuł:
Application of High–resolution Reflection Seismic Attributes for Researching 3D Shallow Marine Geology Structures
Zastosowanie atrybutów sejsmicznych odbić o wysokiej rozdzielczości do badania struktur 3D płytkiej geologii morskiej
Autorzy:
Le, Cuong Van Anh
Duong, Man Ba
Nguyen, Thuan Van
Nguyen, Truong Ngoc
Powiązania:
https://bibliotekanauki.pl/articles/2201256.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
high-resolution seismic
textural attribute
bathymetry
color-blend
sejsmika wysokiej rozdzielczości
atrybut tekstury
batymetria
mieszanie kolorów
Opis:
In river sedimentology and bathymetry study, high–resolution seismic approach equipped with a sub–bottom profiler is necessary. Difference of acoustic impedances resulted by varies of sediment stratigraphy layers can be visualized through dynamic seismic vibration. In marine environments, detection of young sediment as sand dunes or mud, mixtures of sand and clay, and clay formations can help policy makers to launch policies or regulations in safety of water transportation as well as civil building infrastructure. We have measured, analyzed, and interpreted an enormous collection of 2D seismic sub-bottom profiles in Can Gio offshore, Ho Chi Minh City, Vietnam for understanding its shallow subsurface young deposits. Our approach is to combine three key seismic textural attributes (i.e., Correlation, Variance, and Homogeneity) in the representation of color-blended attribute for picking distinguished geological features. In our result, 2D seismic horizons representing boundaries of diverse types of sediments can provide a great input for modeling 3D seabed and distribution of sand, sand-clay mixture, and clay sediments within the interest area. The sand layer useful for mining in this area is strongly affected by channels stemming from Soai Rap river.
W badaniach sedymentologicznych i batymetrycznych rzek konieczne jest podejście sejsmiczne o wysokiej rozdzielczości wyposażone w profiler poddenny. Różnicę impedancji akustycznych wynikającą ze zmienności warstw stratygraficznych osadów można zwizualizować za pomocą dynamicznych drgań sejsmicznych. W środowiskach morskich wykrywanie młodych osadów, takich jak wydmy lub błoto, mieszanki piasku i gliny oraz formacje gliny, może pomoc decydentom we wprowadzaniu polityk lub przepisów dotyczących bezpieczeństwa transportu wodnego, a także infrastruktury budynków cywilnych. Zmierzyliśmy, przeanalizowaliśmy i zinterpretowaliśmy ogromny zbiór profili sejsmicznych 2D pod dnem w Can Gio na morzu w mieście Ho Chi Minh w Wietnamie, aby zrozumieć jego płytkie, podpowierzchniowe młode złoża. Nasze podejście polega na połączeniu trzech kluczowych atrybutów tekstury sejsmicznej (tj. Korelacji, Wariancji i Jednorodności) w reprezentacji atrybutu mieszania kolorów w celu wybrania wyróżniających się cech geologicznych. W naszym wyniku, poziomy sejsmiczne 2D reprezentujące granice rożnych typów osadów mogą stanowić doskonały materiał wejściowy do modelowania 3D dna morskiego i rozmieszczenia piasku, mieszanki piaskowo-gliniastej i osadów gliniastych w obszarze zainteresowania. Na warstwę piasku przydatnego do wydobycia na tym obszarze duży wpływ mają kanały wychodzące z rzeki Soai Rap..
Źródło:
Inżynieria Mineralna; 2023, 1; 175--184
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gas Hydrate Detection Based on High Resolution Seismic Data in the Southeastern Offshore of Vietnam
Autorzy:
Mai, Thanh Tan
Mai, Thanh Ha
Nguyen, Quoc Huy
Nguyen, Nhu Trung
Powiązania:
https://bibliotekanauki.pl/articles/27323248.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
gas hydrate
high resolution seismic
Gas Hydrate Stability Zones/GHSZ
Bottom Simulated Reflector/BSR
gaz
sejsmika
hydratacja
Opis:
Gas hydrates are the accumulations of methane (natural gas) trapped in ice-like structures with water. Gas hydrates represent an immense energy resource underlying large portions of the world’s marine continental shelves. Vietnam has a large continental shelf area, in the deep water zone with suitable low temperatures and high pressure, which is suitable for the formation and existence of potential energy source of Gas Hydrate (GH). The application of High-Resolution Seismic method (HRS) plays an important role in exploring for Gas Hydrate. The enhancement of HRS research such as optimal short - reception conditions and advanced data processing suitable for Gas Hydrate in shallow layers below the seafloor, allows for determining the geological factors related to Gas Hydrate’s existence in the deep water area. Advancements in data processing technology, such as noise filters (Radon, F-K, SRMA, Tau-P..), seismic attributes analysis, seismic migration, AVO, seismic inversion, pre-stack seismic data and AI technology … allow to identify of the signs of Gas Hydrate presence, such as Bottom Simulated Reflector (BSR), Gas Hydrate Stability Zone (GHSZ), Pockmark, Chimney, etc. This paper presents some of the results obtained from applying High-Resolution Seismic method to predict the distribution of Gas hydrate in the Southeastern offshore of Vietnam.
Źródło:
Inżynieria Mineralna; 2023, 2; 137--142
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Marine Sediments with a Subbottom Profilers System in West Coast of Camau, Vietnam
Autorzy:
Dung, Nguyen Quang
Giang, Nguyen Van
Thanh, Le Ngoc
Powiązania:
https://bibliotekanauki.pl/articles/27323269.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
west coast of Camau
high-resolution shallow seismic
sub-bottom profiler
cross-section
Holocene-Pleistocene sediments
Sejsmika
Wietnam
profile
Opis:
The west coast of Camau (Southeast Vietnam) connects two semi-enclosed East Sea and Thailand Bays, allowing water exchange between them. Despite its importance to the oceanographic evolution of the region, it has still been poorly studied. Therefore, Subbottom profilers are used across shallow sea waters with some applications, such as sea-level studies, sedimentation process and geomorphology. In the whole survey area, 6 high-resolution shallow seismic measurements have been performed with a total length of 60.6 km, and all have recorded good reflected signals in the range 20–70 ms. In this section, physical characteristics and nature of petrology in the survey environment are quite uniformly shown. The topography of the seabed in the survey area tends to be gradually shallower from west to east, and is relatively flat. Particularly, on the cross section of the T1 line, it is visible that the first section of the line has a rather steep and deep terrain, which may be the slope of the continental shelf in the survey area. Wedge-shaped, oblique, corrugated and transverse structures all appear on the cross-sections. In the survey area, the shallow geological structure in the Holocene sediments is divided into 4 layers, and the structural boundary between the Holocene and Pleistocene sediments at the depth of 25–35 m is observed. In addition, geological faults are also detected on geological sections from seismic sections. For instance, at the section of T6 line, two faults were detected at the beginning of the line. The displacement amplitude of these faults ranges between 1.5–4 m. This new dataset will contribute to future comprehension of the geologic and oceanographic evolution.
Źródło:
Inżynieria Mineralna; 2023, 2; 215--223
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of computational grid resolution on the quality of forecasts of dangerous convection phenomena: a case study of August 11, 2017
Autorzy:
Mazur, Andrzej
Duniec, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2166587.pdf
Data publikacji:
2022
Wydawca:
Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:
meteorological model
supercell
high-resolution approach
convection-permitting scale
Opis:
On August 11, 2017, a violent convection phenomenon took place in northwestern Poland, i.e., a storm combined with intense rainfall and hurricane winds. This paper presents an attempt to analyze this case by using the results of a numerical weather model, at grid spacings of 7 km, 2.8 km, and 0.7 km. Various convective indicators were analyzed to assess the nature of the event. The key question the authors try to answer is: „To what extent, if any, did a tenfold increase in resolution improve the quality of the numerical forecasts?” This question, however, has not been conclusively resolved. The most likely cause of this event was a supercell rapidly moving from south to northeast. This supercell's path has been mapped (qualitatively at least) by the Supercell Detection Index at all resolutions used. As the resolution increased, the forecasted maximum gusts also increased from 25 m/s in the domain with a resolution of 7 km to 35 m/s at a resolution of 2.8 km and up to about 50 m/s at the highest resolution of 0.7 km. A key conclusion is that the results of the model at a resolution of 2.8 km are much closer to reality than at 7 km. This effect did not pertain to differences between the 2.8 km and 0.7 km models. The latter increase in resolution did not significantly improve the quality of the forecast.
Źródło:
Meteorology Hydrology and Water Management. Research and Operational Applications; 2022, 10, 2; 1--18
2299-3835
2353-5652
Pojawia się w:
Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method of high timing resolution pulse synthesis based on virtual sampling
Autorzy:
Liu, Hanglin
Fu, Zaiming
Kong, Dexuan
Wang, Houjun
Xiao, Yingdong
Powiązania:
https://bibliotekanauki.pl/articles/2106417.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pulse synthesis
high resolution
virtual sampling
digital-to-analogue conversion
downsampling
Opis:
Adjustable-width pulse signals are widely used in systems such as test equipment for hold time, response time and radar testing. In this study, we proposed a pulse generation method based on virtual sampling with ultra-high pulse width resolution. In the proposed method, the sampling rate of a digital-to-analogue converter (DAC) was adjusted to considerably improve pulse width resolution. First, the sampling rate was matched with the target pulse width resolution to digitally sample the ideal signal and generate digital waveform sampling points. Next, the signal bandwidth of the DAC was matched using a low-pass digital filter. Finally, the waveform sampling points were downsampled using an integer factor and output after digital-to-analogue conversion. The waveform pulse width information generated by high-frequency digital sampling was passed step by step and retained in the final output analogue signal. A DAC with a sampling rate of 1.25 GSa/s was used, and the pulse width resolution of the pulse signal was 0.1 ns. Theoretically, a sampling rate of 10 GSa/s is required to achieve 0.1 ns resolution. This method is simple, has a low cost, and exhibits excellent performance.
Źródło:
Metrology and Measurement Systems; 2022, 29, 2; 373--389
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiscale evaluation of a thin-bed reservoir
Autorzy:
Lis-Śledziona, Anita
Powiązania:
https://bibliotekanauki.pl/articles/1841759.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
thin beds
high resolution well logs prediction
horizontal resistivity
unsupervised neural network
self-organizing maps (SOM)
electrofacies
low resistivity pay
Opis:
A thin-bed laminated shaly-sand reservoir of the Miocene formation was evaluated using two methods: high resolution microresistivity data from the XRMI tool and conventional well logs. Based on high resolution data, the Earth model of the reservoir was defined in a way that allowed the analyzed interval to be subdivided into thin layers of sandstones, mudstones, and claystones. Theoretical logs of gamma ray, bulk density, horizontal and vertical resistivity were calculated based on the forward modeling method to describe the petrophysical properties of individual beds and calculate the clay volume, porosity, and water saturation. The relationships amongst the contents of minerals were established based on the XRD data from the neighboring wells; hence, the high-resolution lithological model was evaluated. Predicted curves and estimated volumes of minerals were used as an input in multimineral solver and based on the assumed petrophysical model the input data were recalculated, reconstructed and compared with the predicted curves. The volumes of minerals and input curves were adjusted during several runs to minimalize the error between predicted and recalculated variables. Another approach was based on electrofacies modeling using unsupervised self-organizing maps. As an input, conventional well logs were used. Then, the evaluated facies model was used during forward modeling of the effective porosity, horizontal resistivity and water saturation. The obtained results were compared and, finally, the effective thickness of the reservoir was established based on the results from the two methods.
Źródło:
Geology, Geophysics and Environment; 2021, 47, 1; 5-20
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocean fronts detection over the Bay of Bengal using changepoint algorithms - A non-parametric approach
Autorzy:
Reddem, V.S.
Muthalagu, R.
Bekkam, V.R.
Eluri, P.R.R.
Jampana, V.
Nimit, K.
Powiązania:
https://bibliotekanauki.pl/articles/2078823.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
ocean front
detection
satellite image
change point analysis
algorithm
advanced very high resolution radiometer
Bengal Bay
Opis:
Oceanic fronts are regions over the oceans where a significant change in the characteristics of the water masses is observed. Advanced Very High Resolution Radiometer (AVHRR) satellite imagery over the Bay of Bengal shows regions that are populated by frontal structures. Over the Bay of Bengal, some of the strongest gradients in temperature and salinity are observed. In recent years, there has been a tremendous growth in the availability of satellite imagery and the necessity of automated fast detection of the frontal features is needed for services like potential fishing zones over open oceans. In this article, an algorithm to infer oceanic fronts over the Bay of Bengal is described using changepoint analysis. The changepoint algorithm is combined in a novel way with a contextual median filter to detect frontal features in AVHRR imagery. The changepoint analysis is a non-parametric technique that does not put thresholds on the gradients of brightness temperatures of the satellite imagery. In the open oceans, the gradients of temperature and salinity are not sharp and changepoint analysis is found to be a useful complementary technique to the existing front detecting methods when combined with contextual median filters.
Źródło:
Oceanologia; 2021, 63, 4; 438-477
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Drought prediction in the Lepelle River basin, South Africa under general circulation model simulations
Autorzy:
Ikegwuoha, Darlington C.
Dinka, Megersa O.
Powiązania:
https://bibliotekanauki.pl/articles/946901.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
drought
high-resolution-climate-data
Lepelle-River-Basin
representative concentration pathways (RCPs)
weather evaluation and planning (WEAP)
Opis:
This study aims to evaluate changes in the frequency and severity of historical droughts (1980–2018) and then model future droughts occurrences (2019–2099) in the Lepelle River Basin (LRB), using Intergovernmental Panel on Climate Change (IPPC) General Circulation Model (GCM) simulations for two representative concentration pathways (RCP8.5 and RCP4.5). Firstly, the present-day and future hydrology of the LRB are modelled using the weather evaluation and planning (WEAP) model. Mann–Kendall tests are conducted to identify climate trends in the LRB. The reconnaissance drought index (RDI) and the streamflow drought index (SDI) are employed to explore hydro-meteorological droughts in the Lepelle River Basin, South Africa. The RDI and SDI are plotted over time to assess drought magnitude and duration. The simulated temporal evolution of RDI and SDI show a significant decrease in wetting periods and a concomitant increasing trend in the dry periods for both the lower and middle sections of the LRB under RCP4.5 as the 22nd century is approached. Lastly, the Spearman and Pearson correlation matrix is used to determine the degrees of association between the RDI and SDI drought indices. A strong positive correlation of 0.836 is computed for the middle and lower sections of the LRB under the RCP8.5 forcing. Further findings indicate that severe to extreme drought above –2.0 magnitude are expected to hit the all three sections of the LRB between 2080 and 2090 under RCP8.5. In the short term, it is suggested that policy actions for drought be implemented to mitigate possible impacts on human and hydro-ecological systems in the LRB.
Źródło:
Journal of Water and Land Development; 2020, 45; 42-53
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Program Copernicus źródłem informacji o dominującym typie drzewostanu w Polsce – ocena dokładności krajowej warstwy wysokorozdzielczej
Copernicus Program as a source of information on the dominant leaf type in Poland – assessment of the accuracy of the national high resolution layer
Autorzy:
Mirończuk, A.
Leszczyńska, A.
Hościło, A.
Powiązania:
https://bibliotekanauki.pl/articles/979243.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
program Copernicus
dane satelitarne
warstwa wysokorozdzielcza
lasy
stopien zmieszania
Polska
leśnictwo
źrodła informacji
typy lasów
copernicus
high resolution layers
forest type
remote sensing
Sentinel-2
Opis:
Information on the spatial distribution and variability of forests is important in monitoring of forest resources, biodiversity assessment, threat prevention, estimation of carbon content and forest management. The Pan−European High Resolution Layers (HRLs) produced as part of the European Earth Monitoring Programme – Copernicus provide detailed information on the land cover characteristics in Europe. The HRLs are produced using satellite imagery based on an interactive rule−based classification. There are the following HRL themes: imperviousness, forest, water and wetness and grasslands. The HRLs are available for the reference year 2012 and 2015, at the spatial resolution of 20 m. The forest related HRL consists of tree cover density, dominant tree type and forest type products. In this study, we performed a) the qualitative and quantitative analysis of the accuracy of the dominant leaf type (DLT) layer for the 2015 year at the national scale, and b) detailed analysis of the data quality at the forest stand level over the selected forest districts. The DLT layer was compared with the national orthophotos. The detailed analysis was carried out using Sentinel−2 images and forest inventory data obtained from the Forest Data Bank over the selected forest districts. The accuracy analysis of the national DLT layer revealed the high omission error equal to 18.8%, and lower commission error of 5.4%. The omission error is mostly related to the omitted orchards and young forest plantations, which are included in the DLT layer. The commission error of the broadleaved forest is related mostly to the small patches of coniferous forest that was misclassified as broadleaved. In general, commission errors were identified more frequently in broadleaved forest than in the coniferous forest. In many locations the patches of coniferous forest were misclassified as broadleaved forest. In general, the area of the broadleaved forest is overestimated.
Źródło:
Sylwan; 2020, 164, 02; 151-160
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship-iceberg detection & classification in sentinel-1 SAR images
Autorzy:
Heiselberg, H.
Powiązania:
https://bibliotekanauki.pl/articles/117491.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
arctic shipping
ship-iceberg detection
sentinel-1
Synthetic Aperture Radar (SAR)
European Space Agency (ESA)
SAR Imagery
copernicus program
ground range detected
high resolution (GRDH)
Opis:
The European Space Agency Sentinel-1 satellites provide good resolution all weather SAR images. We describe algorithms for detection and classification of ships, icebergs and other objects at sea. Sidelobes from strongly reflecting objects as large ships are suppressed for better determination of ship parameters. The resulting improved ship lengths and breadths are larger than the ground truth values known from Automatic Identification System (AIS) data due to the limited resolution in the processing of the SAR images as compared to previous analyses of Sentinel-2 optical images. The limited resolution in SAR imagery degrades spatial classification algorithms but it is found that the backscatter horizontal and vertical polarizations can be exploited to distinguish icebergs in the Arctic from large ships but not small boats or wakes.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 1; 235-241
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifying undrained layers from mature gas reservoirs using reservoir simulation and high resolution geophysical investigation
Autorzy:
Tătaru, Argentina
Simescu, Ana Maria
Bolázs, Sándor
Powiązania:
https://bibliotekanauki.pl/articles/298922.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
mature reservoir
decline curve
resources
reserves
3D simulation
high resolution
gas saturated layer
production surface
net thickness
porosity
Opis:
While big discoveries and major new developments deservedly grab the headlines, mature fields are the backbone of gas production. Revitalizing these fields extends their productive lives and offers significant opportunity to expand worldwide reserves. Regardless of the definition, mature fields are a huge resource. With reserves categorized as proved or probable, attempts to expand reserve levels come at a relatively low risk. Revitalizing a mature field means taking measures that increase the value extracted from the field beyond original expectation. Using specialized software brings new opportunities in reservoir simulation of mature gas reservoirs. Combining these simulations with high resolution geophysical investigations, will offer a other perspective about mature gas reservoirs as well as the identification of potentially gas bearing layers which in the first place were not been identified through logging, and in addition to a eventual growth of gas resources but also gas reserves that could be exploited. Identifying the thinest gas saturated layers, determine the modification of gas resources and reserves values. The increase of volumes is a result of larger production surfaces, larger net thicknesses and also larger porosity attributed to this zones. For mature gas reservoirs this kind of approach offers new perspectives.
Źródło:
AGH Drilling, Oil, Gas; 2019, 36, 1; 125-141
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Is there added value of convection-permitting regional climate model simulations for storms over the German Bight and Northern Germany?
Autorzy:
Schaaf, B.
Feser, F.
Powiązania:
https://bibliotekanauki.pl/articles/108627.pdf
Data publikacji:
2018
Wydawca:
Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:
case study
wind
very high resolution
regional climate modelling
added value
storm
cloud-resolving
convection-permitting
wiatr
burza
regionalne modelowanie klimatu
wartość dodana
studium przypadku
Niemcy
Opis:
This study tackles the question: Do very high-resolution convective-permitting regional climate model (RCM) simulations add value compared to coarser RCM runs for certain extreme weather conditions, namely strong wind and storm situations? Ten strong storm cases of the last two decades were selected and dynamically downscaled with the RCM COSMO-CLM (24 and 2.8 km grid point distance). These cyclones crossed the high-resolution model domain, which encompasses the German Bight, Northern Germany, and parts of the Baltic Sea. One storm case study (storm Christian of October 2013) is discussed in more detail in order to analyze the smallscale storm features and the associated potential added value of the high-resolution simulation. The results indicate an added value for atmospheric dynamical processes such as convective precipitation or post-frontal cloud cover. The multiple storm analysis revealed added value for the high-resolution regional climate simulation for 10 m wind speed, mean sea level pressure, and total cloud cover for most storms which were examined, but the improvements are small. Wind direction and precipitation were already well simulated by the coarser RCM and the higher resolution could often not add any value for these variables. The analysis showed that the added value is more distinct for the synoptic comparisons than for the multiple storm study analyzed with statistical measures like the Brier Skill Score.
Źródło:
Meteorology Hydrology and Water Management. Research and Operational Applications; 2018, 6, 2; 21-37
2299-3835
2353-5652
Pojawia się w:
Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Precipitation estimation and nowcasting at IMGW-PIB (SEiNO system)
Autorzy:
Szturc, J.
Jurczyk, A.
Ośródka, K.
Wyszogrodzki, A.
Giszterowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/108484.pdf
Data publikacji:
2018
Wydawca:
Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:
opad atmosferyczny
prognoza probabilistyczna
szacowanie
opad
dane
wysoka rozdzielczość
precipitation
nowcasting
probabilistic forecast
precipitation estimation
high-resolution data
Opis:
A System for the Estimation and Nowcasting of Precipitation (SEiNO) is being developed at the Institute of Meteorology and Water Management – National Research Institute. Its aim is to provide the national meteorological and hydrological service with comprehensive operational tools for real-time high-resolution analyses and forecasts of precipitation fields. The system consists of numerical models for: (i) precipitation field analysis (estimation), (ii) precipitation nowcasting, i.e., extrapolation forecasting for short lead times, (iii) generation of probabilistic nowcasts. The precipitation estimation is performed by the conditional merging of information from telemetric rain gauges, the weather radar network, and the Meteosat satellite, employing quantitative quality information (quality index). Nowcasts are generated by three numerical models, employing various approaches to take account of different aspects of convective phenomena. Probabilistic forecasts are computed based on the investigation of deterministic forecast reliability determined in real time. Some elements of the SEiNO system are still under development and the system will be modernized continuously to reflect the progress in measurement techniques and advanced methods of meteorological data processing.
Źródło:
Meteorology Hydrology and Water Management. Research and Operational Applications; 2018, 6, 1; 1-12
2299-3835
2353-5652
Pojawia się w:
Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
1.25GS/S 12bit and 2.27mW digital to analog converter (DAC) with 70.22 SNDR based on new hybrid R-C procedure in 180nm CMOS
Autorzy:
Mahdavi, S.
Poreh, M.
Alizadeh, L.
Moradkhani, B.
Ebrahimi, R.
Powiązania:
https://bibliotekanauki.pl/articles/398146.pdf
Data publikacji:
2017
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
SAR ADC
DAC
high-resolution
power consumption
high-speed
wysoka rozdzielczość
pobór mocy
Opis:
This paper presents a novel fully differential high-speed and high-resolution Digital to Analog Converter (DAC) based on new reliable hybrid R-C technique. In the proposed idea the four LSB bits and eight MSB bits are implemented as a resistor string and new merged capacitor technique respectively. Applying the suggested method the SNDR and Effective Number of Bits (ENOB) of the proposed DAC achieve 70.22dB and 11.41 bit at the 1.25GS/s sampling rate correspondingly. In the proposed method the total capacitors of the 8 MSB bits are reduced up to 78% compared to the conventional one noticeably. As a result, the power consumption and speed of the suggested DAC are decreased and increased respectively. Moreover, the total power consumption of the proposed DAC is 2.27mW with the power supply of 1.8 volts as well. Meanwhile, for the correctness of the proposed 12bit DAC, 200 iterations in transient Monte-Carlo analysis (parasitic capacitance included ([symbol] mismatch = 1.2%)), and the SNDR simulation results versus different input frequency at fS=1.25GS/s sampling rate are applied too. The maximum Integral Nonlinearity (INL) and the maximum Differential Nonlinearity (DNL) are -0.47/+0.35LSB and -0.42/+0.29 LSB respectively. The proposed DAC structure is simulated in all process corners and performed using the HSPICE BSIM3 model of a 0.18μm CMOS technology.
Źródło:
International Journal of Microelectronics and Computer Science; 2017, 8, 4; 127-132
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
G4 Multi-constellation Precise Point Positioning service for high accuracy offshore navigation
Autorzy:
Tegedor, J.
Ørpen, O.
Melgård, T.
Łapucha, D.
Visser, H.
Powiązania:
https://bibliotekanauki.pl/articles/115985.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Global Navigation Satellite Systems (GNSS)
high accuracy offshore navigation
Precise Point Positioning (PPP)
Integer-Ambiguity Resolution (IAR)
G4 system architecture
Multi-constellation Precise Point Positioning Service
offshore navigation
positioning accuracy
Opis:
Fugro is operating a global GNSS infrastructure for the delivery of high-accuracy multi-constellation Precise Point Positioning (PPP) service, named G4. Precise orbit and clock for all global satellite navigation systems are estimated in real-time and broadcast to the users using geostationary satellites. End-users with a G4-enabled receiver are able to obtain sub-decimeter positioning accuracy in real-time. The system has been tailored for offshore applications where a nearby GNSS station is not always readily available. G4 offers seamless integration of GPS, GLONASS, Galileo and BeiDou in the navigation solution, therefore allowing the user to obtain a reliable and accurate position even in challenging environments, especially in presence of interference, scintillation or partial sky visibility. In addition, carrier-phase integer-ambiguity resolution (IAR) is supported, for those users requiring the highest possible navigation accuracy. This paper presents the G4 system architecture and current performance. The benefits of multi-constellation Precise Point Positioning (PPP) are shown in terms of increased availability, robustness and accuracy.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2017, 11, 3; 425-429
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł

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