Log in

Relevant bibliographies by topics / Radiative transfer models (RTM) / Journal articles

To see the other types of publications on this topic, follow the link: Radiative transfer models (RTM).

Journal articles on the topic 'Radiative transfer models (RTM)'

Author: Grafiati

Published: 11 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Radiative transfer models (RTM).'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Oh, Yisok, Jisung Geba Chang, and Maxim Shoshany. "An Improved Radiative Transfer Model for Polarimetric Backscattering from Agricultural Fields at C- and X-Bands." Journal of Electromagnetic Engineering and Science 21, no. 2 (2021): 104–10. http://dx.doi.org/10.26866/jees.2021.21.2.104.

Full text

Abstract:

The first-order vector radiative transfer model (FVRTM) is modified mainly by examining the effects of leaf curvature of vegetation canopies, the higher-order multiple scattering among vegetation scattering particles, and the underlying-surface roughness for forward reflection on radar backscattering from farming fields at C- and X-bands. At first, we collected the backscattering coefficients measured by scatterometers and space-borne synthetic aperture radar (SAR), field-measured ground-truth data sets, and theoretical scattering models for radar backscattering from vegetation fields at micro

APA, Harvard, Vancouver, ISO, and other styles

2

del Águila, Ana, Dmitry S. Efremenko, Víctor Molina García, and Michael Yu Kataev. "Cluster Low-Streams Regression Method for Hyperspectral Radiative Transfer Computations: Cases of O2 A- and CO2 Bands." Remote Sensing 12, no. 8 (2020): 1250. http://dx.doi.org/10.3390/rs12081250.

Full text

Abstract:

Current atmospheric composition sensors provide a large amount of high spectral resolution data. The accurate processing of this data employs time-consuming line-by-line (LBL) radiative transfer models (RTMs). In this paper, we describe a method to accelerate hyperspectral radiative transfer models based on the clustering of the spectral radiances computed with a low-stream RTM and the regression analysis performed for the low-stream and multi-stream RTMs within each cluster. This approach, which we refer to as the Cluster Low-Streams Regression (CLSR) method, is applied for computing the radi

APA, Harvard, Vancouver, ISO, and other styles

3

Mejia, Felipe A., Ben Kurtz, Keenan Murray, et al. "Coupling sky images with radiative transfer models: a new method to estimate cloud optical depth." Atmospheric Measurement Techniques 9, no. 8 (2016): 4151–65. http://dx.doi.org/10.5194/amt-9-4151-2016.

Full text

Abstract:

Abstract. A method for retrieving cloud optical depth (τc) using a UCSD developed ground-based sky imager (USI) is presented. The radiance red–blue ratio (RRBR) method is motivated from the analysis of simulated images of various τc produced by a radiative transfer model (RTM). From these images the basic parameters affecting the radiance and red–blue ratio (RBR) of a pixel are identified as the solar zenith angle (θ0), τc, solar pixel angle/scattering angle (ϑs), and pixel zenith angle/view angle (ϑz). The effects of these parameters are described and the functions for radiance, Iλτc, θ0, ϑs,

APA, Harvard, Vancouver, ISO, and other styles

4

Vicent, Jorge, Jochem Verrelst, Neus Sabater, et al. "Comparative analysis of atmospheric radiative transfer models using the Atmospheric Look-up table Generator (ALG) toolbox (version 2.0)." Geoscientific Model Development 13, no. 4 (2020): 1945–57. http://dx.doi.org/10.5194/gmd-13-1945-2020.

Full text

Abstract:

Abstract. Atmospheric radiative transfer models (RTMs) are software tools that help researchers in understanding the radiative processes occurring in the Earth's atmosphere. Given their importance in remote sensing applications, the intercomparison of atmospheric RTMs is therefore one of the main tasks used to evaluate model performance and identify the characteristics that differ between models. This can be a tedious tasks that requires good knowledge of the model inputs/outputs and the generation of large databases of consistent simulations. With the evolution of these software tools, their

APA, Harvard, Vancouver, ISO, and other styles

5

Karthikeyan, Lanka, Ming Pan, Dasika Nagesh Kumar, and Eric F. Wood. "Effect of Structural Uncertainty in Passive Microwave Soil Moisture Retrieval Algorithm." Sensors 20, no. 4 (2020): 1225. http://dx.doi.org/10.3390/s20041225.

Full text

Abstract:

Passive microwave sensors use a radiative transfer model (RTM) to retrieve soil moisture (SM) using brightness temperatures (TB) at low microwave frequencies. Vegetation optical depth (VOD) is a key input to the RTM. Retrieval algorithms can analytically invert the RTM using dual-polarized TB measurements to retrieve the VOD and SM concurrently. Algorithms in this regard typically use the τ-ω types of models, which consist of two third-order polynomial equations and, thus, can have multiple solutions. Through this work, we find that uncertainty occurs due to the structural indeterminacy that i

APA, Harvard, Vancouver, ISO, and other styles

6

Seidel, F. C., A. A. Kokhanovsky, and M. E. Schaepman. "Fast and simple model for atmospheric radiative transfer." Atmospheric Measurement Techniques Discussions 3, no. 3 (2010): 2225–73. http://dx.doi.org/10.5194/amtd-3-2225-2010.

Full text

Abstract:

Abstract. Radiative transfer models (RTMs) are of utmost importance for quantitative remote sensing, especially for compensating atmospheric perturbation. A persistent trade-off exists between approaches that prefer accuracy at the cost of computational complexity, versus those favouring simplicity at the cost of reduced accuracy. We propose an approach in the latter category, using analytical equations, parameterizations and a correction factor to efficiently estimate the effect of molecular multiple scattering. We discuss the approximations together with an analysis of the resulting performa

APA, Harvard, Vancouver, ISO, and other styles

7

Seidel, F. C., A. A. Kokhanovsky, and M. E. Schaepman. "Fast and simple model for atmospheric radiative transfer." Atmospheric Measurement Techniques 3, no. 4 (2010): 1129–41. http://dx.doi.org/10.5194/amt-3-1129-2010.

Full text

Abstract:

Abstract. Radiative transfer models (RTMs) are of utmost importance for quantitative remote sensing, especially for compensating atmospheric perturbation. A persistent trade-off exists between approaches that prefer accuracy at the cost of computational complexity, versus those favouring simplicity at the cost of reduced accuracy. We propose an approach in the latter category, using analytical equations, parameterizations and a correction factor to efficiently estimate the effect of molecular multiple scattering. We discuss the approximations together with an analysis of the resulting performa

APA, Harvard, Vancouver, ISO, and other styles

8

Albino, André, Daniele Bortoli, Mouhaydine Tlemçani, Abdeloawahed Hajjaji, and António Joyce. "Sensitivity analysis of atmospheric spectral irradiance model." European Physical Journal Applied Physics 88, no. 1 (2019): 11001. http://dx.doi.org/10.1051/epjap/2019190350.

Full text

Abstract:

Many Radiative Transfer Models (RTM) have been developed to simulate and estimate solar irradiance. Theirs accuracy is well documents in literature nonetheless the effect of the parameters uncertainties on the established models has not been well studied yet. This work focuses on implementing a RTM based on the models found in the literature along with some updates, with the aim to study the sensitivity of the model towards the variations of the input parameters. The parameters studied in this paper are: the day of the year, the solar zenith angle, the local atmospheric pressure, the local tem

APA, Harvard, Vancouver, ISO, and other styles

9

del Águila, Ana, and Dmitry S. Efremenko. "Fast Hyper-Spectral Radiative Transfer Model Based on the Double Cluster Low-Streams Regression Method." Remote Sensing 13, no. 3 (2021): 434. http://dx.doi.org/10.3390/rs13030434.

Full text

Abstract:

Fast radiative transfer models (RTMs) are required to process a great amount of satellite-based atmospheric composition data. Specifically designed acceleration techniques can be incorporated in RTMs to simulate the reflected radiances with a fine spectral resolution, avoiding time-consuming computations on a fine resolution grid. In particular, in the cluster low-streams regression (CLSR) method, the computations on a fine resolution grid are performed by using the fast two-stream RTM, and then the spectra are corrected by using regression models between the two-stream and multi-stream RTMs.

APA, Harvard, Vancouver, ISO, and other styles

10

Abdelbaki, Asmaa, and Thomas Udelhoven. "A Review of Hybrid Approaches for Quantitative Assessment of Crop Traits Using Optical Remote Sensing: Research Trends and Future Directions." Remote Sensing 14, no. 15 (2022): 3515. http://dx.doi.org/10.3390/rs14153515.

Full text

Abstract:

Remote sensing technology allows to provide information about biochemical and biophysical crop traits and monitor their spatiotemporal dynamics of agriculture ecosystems. Among multiple retrieval techniques, hybrid approaches have been found to provide outstanding accuracy, for instance, for the inference of leaf area index (LAI), fractional vegetation cover (fCover), and leaf and canopy chlorophyll content (LCC and CCC). The combination of radiative transfer models (RTMs) and data-driven models creates an advantage in the use of hybrid methods. Through this review paper, we aim to provide sta

APA, Harvard, Vancouver, ISO, and other styles

11

Zhang, Xuanze, Xiaogu Zheng, Zhian Sun, and San Luo. "Trends of MSU Brightness Temperature in the Middle Troposphere Simulated by CMIP5 Models and Their Sensitivity to Cloud Liquid Water." Journal of Atmospheric and Oceanic Technology 32, no. 5 (2015): 1029–41. http://dx.doi.org/10.1175/jtech-d-13-00250.1.

Full text

Abstract:

AbstractOnly a climate model that is able to simulate well the historical atmospheric temperature trend can be used for estimating the future atmospheric temperature trends on different emission scenarios. Satellite-based Microwave Sounding Unit (MSU) brightness temperature in the middle troposphere (T2) is an important analog of midtropospheric atmospheric temperature. So, there is the need to compare the atmospheric temperature trend simulated by the fifth phase of the Coupled Model Intercomparison Project (CMIP5) historical realizations and the observed MSU T2. There are two approaches for

APA, Harvard, Vancouver, ISO, and other styles

12

Melendo-Vega, José, M. Martín, Javier Pacheco-Labrador, et al. "Improving the Performance of 3-D Radiative Transfer Model FLIGHT to Simulate Optical Properties of a Tree-Grass Ecosystem." Remote Sensing 10, no. 12 (2018): 2061. http://dx.doi.org/10.3390/rs10122061.

Full text

Abstract:

The 3-D Radiative Transfer Model (RTM) FLIGHT can represent scattering in open forest or savannas featuring underlying bare soils. However, FLIGHT might not be suitable for multilayered tree-grass ecosystems (TGE), where a grass understory can dominate the reflectance factor (RF) dynamics due to strong seasonal variability and low tree fractional cover. To address this issue, we coupled FLIGHT with the 1-D RTM PROSAIL. The model is evaluated against spectral observations of proximal and remote sensing sensors: the ASD Fieldspec® 3 spectroradiometer, the Airborne Spectrographic Imager (CASI) an

APA, Harvard, Vancouver, ISO, and other styles

13

Lisok, Justyna, Anna Rozwadowska, Jesper G. Pedersen, et al. "Radiative impact of an extreme Arctic biomass-burning event." Atmospheric Chemistry and Physics 18, no. 12 (2018): 8829–48. http://dx.doi.org/10.5194/acp-18-8829-2018.

Full text

Abstract:

Abstract. The aim of the presented study was to investigate the impact on the radiation budget of a biomass-burning plume, transported from Alaska to the High Arctic region of Ny-Ålesund, Svalbard, in early July 2015. Since the mean aerosol optical depth increased by the factor of 10 above the average summer background values, this large aerosol load event is considered particularly exceptional in the last 25 years. In situ data with hygroscopic growth equations, as well as remote sensing measurements as inputs to radiative transfer models, were used, in order to estimate biases associated wit

APA, Harvard, Vancouver, ISO, and other styles

14

Bates, T. S., T. L. Anderson, T. Baynard, et al. "Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling." Atmospheric Chemistry and Physics Discussions 6, no. 1 (2006): 175–362. http://dx.doi.org/10.5194/acpd-6-175-2006.

Full text

Abstract:

Abstract. The largest uncertainty in the radiative forcing of climate change over the industrial era is that due to aerosols, a substantial fraction of which is the uncertainty associated with scattering and absorption of shortwave (solar) radiation by anthropogenic aerosols in cloud-free conditions (IPCC, 2001). Quantifying and reducing the uncertainty in aerosol influences on climate is critical to understanding climate change over the industrial period and to improving predictions of future climate change for assumed emission scenarios. Measurements of aerosol properties during major field

APA, Harvard, Vancouver, ISO, and other styles

15

Zhang, Hu, Jing Li, Qinhuo Liu, et al. "Estimating Leaf Area Index with Dynamic Leaf Optical Properties." Remote Sensing 13, no. 23 (2021): 4898. http://dx.doi.org/10.3390/rs13234898.

Full text

Abstract:

Leaf area index (LAI) plays an important role in models of climate, hydrology, and ecosystem productivity. The physical model-based inversion method is a practical approach for large-scale LAI inversion. However, the ill-posed inversion problem, due to the limited constraint of inaccurate input parameters, is the dominant source of inversion errors. For instance, variables related to leaf optical properties are always set as constants or have large ranges, instead of the actual leaf reflectance of pixel vegetation in the current model-based inversions. This paper proposes to estimate LAI with

APA, Harvard, Vancouver, ISO, and other styles

16

Marino, Eva, Marta Yebra, Mariluz Guillén-Climent, et al. "Investigating Live Fuel Moisture Content Estimation in Fire-Prone Shrubland from Remote Sensing Using Empirical Modelling and RTM Simulations." Remote Sensing 12, no. 14 (2020): 2251. http://dx.doi.org/10.3390/rs12142251.

Full text

Abstract:

Previous research has demonstrated that remote sensing can provide spectral information related to vegetation moisture variations essential for estimating live fuel moisture content (LFMC), but accuracy and timeliness still present challenges to using this information operationally. Consequently, many regional administrations are investing important resources in field campaigns for LFMC monitoring, often focusing on indicator species to reduce sampling time and costs. This paper compares different remote sensing approaches to provide LFMC prediction of Cistus ladanifer, a fire-prone shrub spec

APA, Harvard, Vancouver, ISO, and other styles

17

Youn, D., K. O. Patten, J. T. Lin, and D. J. Wuebbles. "Explicit calculation of indirect global warming potentials for halons using atmospheric models." Atmospheric Chemistry and Physics Discussions 9, no. 4 (2009): 15511–40. http://dx.doi.org/10.5194/acpd-9-15511-2009.

Full text

Abstract:

Abstract. The concept of Global Warming Potentials (GWPs) has been extensively used in policy consideration as a relative index for comparing the climate impact of an emitted greenhouse gas (GHG), relative to carbon dioxide with equal mass emissions. Ozone depletion due to emission of chlorinated or brominated halocarbons leads to cooling of the climate system in the opposite direction to the direct warming contribution by halocarbons as GHGs. This cooling is a key indirect effect of the halocarbons on climatic radiative forcing, which is accounted for by indirect GWPs. With respect to climate

APA, Harvard, Vancouver, ISO, and other styles

18

Wagner, T., J. P. Burrows, T. Deutschmann, et al. "Comparison of box-air-mass-factors and radiances for Multiple-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) geometries calculated from different UV/visible radiative transfer models." Atmospheric Chemistry and Physics 7, no. 7 (2007): 1809–33. http://dx.doi.org/10.5194/acp-7-1809-2007.

Full text

Abstract:

Abstract. The results of a comparison exercise of radiative transfer models (RTM) of various international research groups for Multiple AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) viewing geometry are presented. Besides the assessment of the agreement between the different models, a second focus of the comparison was the systematic investigation of the sensitivity of the MAX-DOAS technique under various viewing geometries and aerosol conditions. In contrast to previous comparison exercises, box-air-mass-factors (box-AMFs) for different atmospheric height layers were modelled,

APA, Harvard, Vancouver, ISO, and other styles

19

Lu, Bing, and Yuhong He. "Evaluating Empirical Regression, Machine Learning, and Radiative Transfer Modelling for Estimating Vegetation Chlorophyll Content Using Bi-Seasonal Hyperspectral Images." Remote Sensing 11, no. 17 (2019): 1979. http://dx.doi.org/10.3390/rs11171979.

Full text

Abstract:

Different types of methods have been developed to retrieve vegetation attributes from remote sensing data, including conventional empirical regressions (i.e., linear regression (LR)), advanced empirical regressions (e.g., multivariable linear regression (MLR), partial least square regression (PLSR)), machine learning (e.g., random forest regression (RFR), decision tree regression (DTR)), and radiative transfer modelling (RTM, e.g., PROSAIL). Given that each algorithm has its own strengths and weaknesses, it is essential to compare them and evaluate their effectiveness. Previous studies have ma

APA, Harvard, Vancouver, ISO, and other styles

20

Bates, T. S., T. L. Anderson, T. Baynard, et al. "Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling." Atmospheric Chemistry and Physics 6, no. 6 (2006): 1657–732. http://dx.doi.org/10.5194/acp-6-1657-2006.

Full text

Abstract:

Abstract. The largest uncertainty in the radiative forcing of climate change over the industrial era is that due to aerosols, a substantial fraction of which is the uncertainty associated with scattering and absorption of shortwave (solar) radiation by anthropogenic aerosols in cloud-free conditions (IPCC, 2001). Quantifying and reducing the uncertainty in aerosol influences on climate is critical to understanding climate change over the industrial period and to improving predictions of future climate change for assumed emission scenarios. Measurements of aerosol properties during major field

APA, Harvard, Vancouver, ISO, and other styles

21

de Sá, Nuno César, Mitra Baratchi, Leon T. Hauser, and Peter van Bodegom. "Exploring the Impact of Noise on Hybrid Inversion of PROSAIL RTM on Sentinel-2 Data." Remote Sensing 13, no. 4 (2021): 648. http://dx.doi.org/10.3390/rs13040648.

Full text

Abstract:

Remote sensing (RS) of biophysical variables plays a vital role in providing the information necessary for understanding spatio-temporal dynamics in ecosystems. The hybrid approach to retrieve biophysical variables from RS by combining Machine Learning (ML) algorithms with surrogate data generated by Radiative Transfer Models (RTM). The susceptibility of the ill-posed solutions to noise currently constrains further application of hybrid approaches. Here, we explored how noise affects the performance of ML algorithms for biophysical trait retrieval. We focused on synthetic Sentinel-2 (S2) data

APA, Harvard, Vancouver, ISO, and other styles

22

Wagner, T., J. P. Burrows, T. Deutschmann, et al. "Comparison of Box-Air-Mass-Factors and Radiances for Multiple-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) Geometries calculated from different UV/visible Radiative Transfer Models." Atmospheric Chemistry and Physics Discussions 6, no. 5 (2006): 9823–76. http://dx.doi.org/10.5194/acpd-6-9823-2006.

Full text

Abstract:

Abstract. The results of a comparison exercise of radiative transfer models (RTM) of various international research groups for Multiple AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) viewing geometry are presented. In contrast to previous comparison exercises, box-air-mass-factors (box-AMFs) for various atmospheric height layers were modelled, which describe the sensitivity of the measurements as a function of altitude. In addition, radiances were calculated allowing the identification of potential errors, which might be overlooked if only AMFs are compared. Accurate modelling of

APA, Harvard, Vancouver, ISO, and other styles

23

García, Rosa Delia, Africa Barreto, Emilio Cuevas, et al. "Comparison of observed and modeled cloud-free longwave downward radiation (2010–2016) at the high mountain BSRN Izaña station." Geoscientific Model Development 11, no. 6 (2018): 2139–52. http://dx.doi.org/10.5194/gmd-11-2139-2018.

Full text

Abstract:

Abstract. A 7-year (2010–2016) comparison study between measured and simulated longwave downward radiation (LDR) under cloud-free conditions was performed at the Izaña Atmospheric Observatory (IZO, Spain). This analysis encompasses a total of 2062 cases distributed approximately evenly between day and night. Results show an excellent agreement between Baseline Surface Radiation Network (BSRN) measurements and simulations with libRadtran V2.0.1 and MODerate resolution atmospheric TRANsmission model (MODTRAN) V6 radiative transfer models (RTMs). Mean bias (simulated − measured) of < 1.1 % and

APA, Harvard, Vancouver, ISO, and other styles

24

Tang, Guanglin, Ping Yang, George W. Kattawar, et al. "Improvement of the Simulation of Cloud Longwave Scattering in Broadband Radiative Transfer Models." Journal of the Atmospheric Sciences 75, no. 7 (2018): 2217–33. http://dx.doi.org/10.1175/jas-d-18-0014.1.

Full text

Abstract:

Abstract Cloud longwave scattering is generally neglected in general circulation models (GCMs), but it plays a significant and highly uncertain role in the atmospheric energy budget as demonstrated in recent studies. To reduce the errors caused by neglecting cloud longwave scattering, two new radiance adjustment methods are developed that retain the computational efficiency of broadband radiative transfer simulations. In particular, two existing scaling methods and the two new adjustment methods are implemented in the Rapid Radiative Transfer Model (RRTM). The results are then compared with th

APA, Harvard, Vancouver, ISO, and other styles

25

Youn, D., K. O. Patten, J. T. Lin, and D. J. Wuebbles. "Explicit calculation of indirect global warming potentials for halons using atmospheric models." Atmospheric Chemistry and Physics 9, no. 22 (2009): 8719–33. http://dx.doi.org/10.5194/acp-9-8719-2009.

Full text

Abstract:

Abstract. The concept of Global Warming Potentials (GWPs) has been extensively used in policy consideration as a relative index for comparing the climate impact of an emitted greenhouse gas (GHG), relative to carbon dioxide with equal mass emissions. Ozone depletion due to emission of chlorinated or brominated halocarbons leads to cooling of the climate system in the opposite direction to the direct warming contribution by halocarbons as GHGs. This cooling is a key indirect effect of the halocarbons on climatic radiative forcing, which is accounted for by indirect GWPs. With respect to climate

APA, Harvard, Vancouver, ISO, and other styles

26

Aires, Filipe, Frédéric Bernardo, Héléne Brogniez, and Catherine Prigent. "An Innovative Calibration Method for the Inversion of Satellite Observations." Journal of Applied Meteorology and Climatology 49, no. 12 (2010): 2458–73. http://dx.doi.org/10.1175/2010jamc2435.1.

Full text

Abstract:

Abstract Retrieval schemes often use two important components: 1) a radiative transfer model (RTM) inside the retrieval procedure or to construct the learning dataset for the training of the statistical retrieval algorithms and 2) a numerical weather prediction (NWP) model to provide a first guess or, again, to construct a learning dataset. This is particularly true in operational centers. As a consequence, any physical retrieval or similar method is limited by inaccuracies in the RTM and NWP models on which it is based. In this paper, a method for partially compensating for these errors as pa

APA, Harvard, Vancouver, ISO, and other styles

27

Aebi, Christine, Julian Gröbner, Stelios Kazadzis, Laurent Vuilleumier, Antonis Gkikas, and Niklaus Kämpfer. "Estimation of cloud optical thickness, single scattering albedo and effective droplet radius using a shortwave radiative closure study in Payerne." Atmospheric Measurement Techniques 13, no. 2 (2020): 907–23. http://dx.doi.org/10.5194/amt-13-907-2020.

Full text

Abstract:

Abstract. We have used a method based on ground-based solar radiation measurements and radiative transfer models (RTMs) in order to estimate the following cloud optical properties: cloud optical thickness (COT), cloud single scattering albedo (SSAc) and effective droplet radius (reff). The method is based on the minimisation of the difference between modelled and measured downward shortwave radiation (DSR). The optical properties are estimated for more than 3000 stratus–altostratus (St–As) and 206 cirrus–cirrostratus (Ci–Cs) measurements during 2013–2017, at the Baseline Surface Radiation Netw

APA, Harvard, Vancouver, ISO, and other styles

28

Verrelst, Jochem, Jorge Vicent, Juan Pablo Rivera-Caicedo, Maria Lumbierres, Pablo Morcillo-Pallarés, and José Moreno. "Global Sensitivity Analysis of Leaf-Canopy-Atmosphere RTMs: Implications for Biophysical Variables Retrieval from Top-of-Atmosphere Radiance Data." Remote Sensing 11, no. 16 (2019): 1923. http://dx.doi.org/10.3390/rs11161923.

Full text

Abstract:

Knowledge of key variables driving the top of the atmosphere (TOA) radiance over a vegetated surface is an important step to derive biophysical variables from TOA radiance data, e.g., as observed by an optical satellite. Coupled leaf-canopy-atmosphere Radiative Transfer Models (RTMs) allow linking vegetation variables directly to the at-sensor TOA radiance measured. Global Sensitivity Analysis (GSA) of RTMs enables the computation of the total contribution of each input variable to the output variance. We determined the impacts of the leaf-canopy-atmosphere variables into TOA radiance using th

APA, Harvard, Vancouver, ISO, and other styles

29

Morcillo-Pallarés, Pablo, Juan Pablo Rivera-Caicedo, Santiago Belda, et al. "Quantifying the Robustness of Vegetation Indices through Global Sensitivity Analysis of Homogeneous and Forest Leaf-Canopy Radiative Transfer Models." Remote Sensing 11, no. 20 (2019): 2418. http://dx.doi.org/10.3390/rs11202418.

Full text

Abstract:

Vegetation indices (VIs) are widely used in optical remote sensing to estimate biophysical variables of vegetated surfaces. With the advent of spectroscopy technology, spectral bands can be combined in numerous ways to extract the desired information. This resulted in a plethora of proposed indices, designed for a diversity of applications and research purposes. However, it is not always clear whether they are sensitive to the variable of interest while at the same time, responding insensitive to confounding factors. Hence, to be able to quantify the robustness of VIs, a systematic evaluation

APA, Harvard, Vancouver, ISO, and other styles

30

Iacovazzi, Robbie, Lin Lin, Ninghai Sun, and Quanhua Liu. "NOAA Operational Microwave Sounding Radiometer Data Quality Monitoring and Anomaly Assessment Using COSMIC GNSS Radio-Occultation Soundings." Remote Sensing 12, no. 5 (2020): 828. http://dx.doi.org/10.3390/rs12050828.

Full text

Abstract:

National Oceanic and Atmospheric Administration (NOAA) operational Advanced Technology Microwave Sounder (ATMS) and Advanced Microwave Sounding Unit-A (AMSU-A) data used in numerical weather prediction and climate analysis are essential to protect life and property and maintain safe and efficient commerce. Routine data quality monitoring and anomaly assessment is important to sustain data effectiveness. One valuable parameter used to monitor microwave sounder data quality is the antenna temperature (Ta) difference (O-B) computed between direct instrument Ta measurements and forward radiative t

APA, Harvard, Vancouver, ISO, and other styles

31

Reyes-Muñoz, Pablo, Luca Pipia, Matías Salinero-Delgado, et al. "Quantifying Fundamental Vegetation Traits over Europe Using the Sentinel-3 OLCI Catalogue in Google Earth Engine." Remote Sensing 14, no. 6 (2022): 1347. http://dx.doi.org/10.3390/rs14061347.

Full text

Abstract:

Thanks to the emergence of cloud-computing platforms and the ability of machine learning methods to solve prediction problems efficiently, this work presents a workflow to automate spatiotemporal mapping of essential vegetation traits from Sentinel-3 (S3) imagery. The traits included leaf chlorophyll content (LCC), leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FAPAR), and fractional vegetation cover (FVC), being fundamental for assessing photosynthetic activity on Earth. The workflow involved Gaussian process regression (GPR) algorithms trained on top-of-atmo

APA, Harvard, Vancouver, ISO, and other styles

32

Markowicz, Krzysztof M., Iwona S. Stachlewska, Olga Zawadzka-Manko, et al. "A Decade of Poland-AOD Aerosol Research Network Observations." Atmosphere 12, no. 12 (2021): 1583. http://dx.doi.org/10.3390/atmos12121583.

Full text

Abstract:

The Poland-AOD aerosol research network was established in 2011 to improve aerosol–climate interaction knowledge and provide a real-time and historical, comprehensive, and quantitative database for the aerosol optical properties distribution over Poland. The network consists of research institutions and private owners operating 10 measurement stations and an organization responsible for aerosol model transport simulations. Poland-AOD collaboration provides observations of spectral aerosol optical depth (AOD), Ångstrom Exponent (AE), incoming shortwave (SW) and longwave (LW) radiation fluxes, v

APA, Harvard, Vancouver, ISO, and other styles

33

Efremenko, Dmitry S. "Discrete Ordinate Radiative Transfer Model With the Neural Network Based Eigenvalue Solver: proof Of Concept." Light & Engineering, no. 01-2021 (February 2021): 56–62. http://dx.doi.org/10.33383/2020-075.

Full text

Abstract:

Artificial neural networks are attracting increasing attention in various applications. They can be used as ‘universal approximations’, which substitute computationally expensive algorithms by relatively simple sequences of functions, which simulate a reaction of a set of neurons to the incoming signal. In particular, neural networks have proved to be efficient for parameterization of the computationally expensive radiative transfer models (RTMs) in atmospheric remote sensing. Although a direct substitution of RTMs by neural networks can lead to the multiple performance enhancements, such an a

APA, Harvard, Vancouver, ISO, and other styles

34

Croci, Michele, Giorgio Impollonia, Andrea Marcone, et al. "RTM Inversion through Predictive Equations for Multi-Crop LAI Retrieval Using Sentinel-2 Images." Agronomy 12, no. 11 (2022): 2835. http://dx.doi.org/10.3390/agronomy12112835.

Full text

Abstract:

Near-real-time, high-spatial-resolution leaf area index (LAI) maps would enable producers to monitor crop health and growth status, improving agricultural practices such as fertiliser and water management. LAI retrieval methods are numerous and can be divided into statistical and physically based methods. While statistical methods are generally subject to high site-specificity but possess high ease of implementation and use, physically based methods are more transferable, albeit more complex to use in operational settings. In addition, statistical methods need a large amount of data for calibr

APA, Harvard, Vancouver, ISO, and other styles

35

del Águila, Ana, Dmitry Efremenko, Víctor Molina García, and Jian Xu. "Analysis of Two Dimensionality Reduction Techniques for Fast Simulation of the Spectral Radiances in the Hartley-Huggins Band." Atmosphere 10, no. 3 (2019): 142. http://dx.doi.org/10.3390/atmos10030142.

Full text

Abstract:

The new generation of atmospheric composition sensors such as TROPOMI is capable of providing spectra of high spatial and spectral resolution. To process this vast amount of spectral information, fast radiative transfer models (RTMs) are required. In this regard, we analyzed the efficiency of two acceleration techniques based on the principal component analysis (PCA) for simulating the Hartley-Huggins band spectra. In the first one, the PCA is used to map the data set of optical properties of the atmosphere to a lower-dimensional subspace, in which the correction function for an approximate bu

APA, Harvard, Vancouver, ISO, and other styles

36

Labdon, Aaron, Stefan Kraus, Claire L. Davies, et al. "Dusty disk winds at the sublimation rim of the highly inclined, low mass young stellar object SU Aurigae." Astronomy & Astrophysics 627 (June 27, 2019): A36. http://dx.doi.org/10.1051/0004-6361/201935331.

Full text

Abstract:

Context. T Tauri stars are low-mass young stars whose disks provide the setting for planet formation. Despite this, their structure is poorly understood. We present new infrared interferometric observations of the SU Aurigae circumstellar environment that offer resolution that is three times higher and a better baseline position angle coverage than previous observations. Aims. We aim to investigate the characteristics of the circumstellar material around SU Aur, constrain the disk geometry, composition and inner dust rim structure. Methods. The CHARA array offers unique opportunities for long

APA, Harvard, Vancouver, ISO, and other styles

37

Alahmadi, Reham A., Jawad Raza, Tahir Mushtaq, Shaimaa A. M. Abdelmohsen, Mohammad R. Gorji, and Ahmed M. Hassan. "Optimization of MHD Flow of Radiative Micropolar Nanofluid in a Channel by RSM: Sensitivity Analysis." Mathematics 11, no. 4 (2023): 939. http://dx.doi.org/10.3390/math11040939.

Full text

Abstract:

These days, heat transfer plays a significant role in the fields of engineering and energy, particularly in the biological sciences. Ordinary fluid is inadequate to transfer heat in an efficient manner, therefore, several models were considered for the betterment of heat transfer. One of the most prominent models is a single-phase nanofluid model. The present study is devoted to solving the problem of micropolar fluid with a single-phase model in a channel numerically. The governing partial differential equations (PDEs) are converted into nonlinear ordinary differential equations (ODEs) by int

APA, Harvard, Vancouver, ISO, and other styles

38

Schwaerzel, Marc, Claudia Emde, Dominik Brunner, et al. "Three-dimensional radiative transfer effects on airborne and ground-based trace gas remote sensing." Atmospheric Measurement Techniques 13, no. 8 (2020): 4277–93. http://dx.doi.org/10.5194/amt-13-4277-2020.

Full text

Abstract:

Abstract. Air mass factors (AMFs) are used in passive trace gas remote sensing for converting slant column densities (SCDs) to vertical column densities (VCDs). AMFs are traditionally computed with 1D radiative transfer models assuming horizontally homogeneous conditions. However, when observations are made with high spatial resolution in a heterogeneous atmosphere or above a heterogeneous surface, 3D effects may not be negligible. To study the importance of 3D effects on AMFs for different types of trace gas remote sensing, we implemented 1D-layer and 3D-box AMFs into the Monte carlo code for

APA, Harvard, Vancouver, ISO, and other styles

39

Revilla, Sergio, María Lamelas, Darío Domingo, et al. "Assessing the Potential of the DART Model to Discrete Return LiDAR Simulation—Application to Fuel Type Mapping." Remote Sensing 13, no. 3 (2021): 342. http://dx.doi.org/10.3390/rs13030342.

Full text

Abstract:

Fuel type is one of the key factors for analyzing the potential of fire ignition and propagation in agricultural and forest environments. The increase of three-dimensional datasets provided by active sensors, such as LiDAR (Light Detection and Ranging), has improved the classification of fuel types through empirical modelling. Empirical methods are site and sensor specific while Radiative Transfer Models (RTM) approaches provide broader universality. The aim of this work is to analyze the suitability of Discrete Anisotropic Radiative Transfer (DART) model to replicate low density small-footpri

APA, Harvard, Vancouver, ISO, and other styles

40

Kosmopoulos, Panagiotis G., Stelios Kazadzis, Michael Taylor, et al. "Assessment of surface solar irradiance derived from real-time modelling techniques and verification with ground-based measurements." Atmospheric Measurement Techniques 11, no. 2 (2018): 907–24. http://dx.doi.org/10.5194/amt-11-907-2018.

Full text

Abstract:

Abstract. This study focuses on the assessment of surface solar radiation (SSR) based on operational neural network (NN) and multi-regression function (MRF) modelling techniques that produce instantaneous (in less than 1 min) outputs. Using real-time cloud and aerosol optical properties inputs from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board the Meteosat Second Generation (MSG) satellite and the Copernicus Atmosphere Monitoring Service (CAMS), respectively, these models are capable of calculating SSR in high resolution (1 nm, 0.05∘, 15 min) that can be used for spectral

APA, Harvard, Vancouver, ISO, and other styles

41

Chakhvashvili, Erekle, Bastian Siegmann, Onno Muller, et al. "Retrieval of Crop Variables from Proximal Multispectral UAV Image Data Using PROSAIL in Maize Canopy." Remote Sensing 14, no. 5 (2022): 1247. http://dx.doi.org/10.3390/rs14051247.

Full text

Abstract:

Mapping crop variables at different growth stages is crucial to inform farmers and plant breeders about the crop status. For mapping purposes, inversion of canopy radiative transfer models (RTMs) is a viable alternative to parametric and non-parametric regression models, which often lack transferability in time and space. Due to the physical nature of RTMs, inversion outputs can be delivered in sound physical units that reflect the underlying processes in the canopy. In this study, we explored the capabilities of the coupled leaf–canopy RTM PROSAIL applied to high-spatial-resolution (0.015 m)

APA, Harvard, Vancouver, ISO, and other styles

42

Scharringhausen, M., A. C. Aikin, J. P. Burrows, and M. Sinnhuber. "First space-borne measurements of the altitude distribution of mesospheric magnesium species." Atmospheric Chemistry and Physics Discussions 7, no. 2 (2007): 4597–656. http://dx.doi.org/10.5194/acpd-7-4597-2007.

Full text

Abstract:

Abstract. We present a joint retrieval as well as first results for mesospheric air density and mesospheric Magnesium species (Mg and Mg+) using limb data from the SCIAMACHY instrument on board the European ENVISAT satellite. Metallic species like neutral Mg, ionized Mg+ and others (Fe, Si, Li, etc.) ablate from meteoric dust, enter the gas phase and occur at high altitudes (≥70 km). Emissions from these species are clearly observed in the SCIAMACHY limb measurements. These emissions are used to retrieve total and thermospheric column densities as well as altitude-resolved profiles of metallic

APA, Harvard, Vancouver, ISO, and other styles

43

Scharringhausen, M., A. C. Aikin, J. P. Burrows, and M. Sinnhuber. "Space-borne measurements of mesospheric magnesium species – a retrieval algorithm and preliminary profiles." Atmospheric Chemistry and Physics 8, no. 7 (2008): 1963–83. http://dx.doi.org/10.5194/acp-8-1963-2008.

Full text

Abstract:

Abstract. We present a joint retrieval as well as first results for mesospheric air density and mesospheric Magnesium species (Mg and Mg+) using limb data from the SCIAMACHY instrument on board the European ENVISAT satellite.considered. These species feature Metallic species like neutral Mg, ionized Mg+ and others (Fe, Si, Li, etc.) ablate from meteoric dust, enter the gas phase and occur at high altitudes (≥70 km). Emissions from these species are clearly observed in the SCIAMACHY limb measurements. These emissions are used to retrieve total and thermospheric column densities as well as preli

APA, Harvard, Vancouver, ISO, and other styles

44

Krieger, A., and S. Wolf. "Unbiased Monte Carlo continuum radiative transfer in optically thick regions." Astronomy & Astrophysics 635 (March 2020): A148. http://dx.doi.org/10.1051/0004-6361/201937355.

Full text

Abstract:

Radiative transfer describes the propagation of electromagnetic radiation through an interacting medium. This process is often simulated by the use of the Monte Carlo method, which involves the probabilistic determination and tracking of simulated photon packages. In the regime of high optical depths, this approach encounters difficulties since a proper representation of the various physical processes can only be achieved by considering high numbers of simulated photon packages. As a consequence, the demand for computation time rises accordingly and thus practically puts a limit on the optical

APA, Harvard, Vancouver, ISO, and other styles

45

Mendiguren, G., M. Pilar Martín, H. Nieto, J. Pacheco-Labrador, and S. Jurdao. "Seasonal variation in grass water content estimated from proximal sensing and MODIS time series in a Mediterranean Fluxnet site." Biogeosciences 12, no. 18 (2015): 5523–35. http://dx.doi.org/10.5194/bg-12-5523-2015.

Full text

Abstract:

Abstract. This study evaluates three different metrics of water content of an herbaceous cover in a Mediterranean wooded grassland (dehesa) ecosystem. Fuel moisture content (FMC), equivalent water thickness (EWT) and canopy water content (CWC) were estimated from proximal sensing and MODIS satellite imagery. Dry matter (Dm) and leaf area index (LAI) connect the three metrics and were also analyzed. Metrics were derived from field sampling of grass cover within a 500 m MODIS pixel. Hand-held hyperspectral measurements and MODIS images were simultaneously acquired and predictive empirical models

APA, Harvard, Vancouver, ISO, and other styles

46

Shellito, Peter J., Sujay V. Kumar, Joseph A. Santanello, et al. "Assessing the Impact of Soil Layer Depth Specification on the Observability of Modeled Soil Moisture and Brightness Temperature." Journal of Hydrometeorology 21, no. 9 (2020): 2041–60. http://dx.doi.org/10.1175/jhm-d-19-0280.1.

Full text

Abstract:

AbstractThe utility of hydrologic land surface models (LSMs) can be enhanced by using information from observational platforms, but mismatches between the two are common. This study assesses the degree to which model agreement with observations is affected by two mechanisms in particular: 1) physical incongruities between the support volumes being characterized and 2) inadequate or inconsistent parameterizations of physical processes. The Noah and Noah-MP LSMs by default characterize surface soil moisture (SSM) in the top 10 cm of the soil column. This depth is notably different from the 5-cm

APA, Harvard, Vancouver, ISO, and other styles

47

RAJEEVAN, M. "Model calculations of non-cloud radiative forcing due to anthropogenic sulphate aerosol." MAUSAM 49, no. 1 (2021): 45–58. http://dx.doi.org/10.54302/mausam.v49i1.3598.

Full text

Abstract:

Anthropogenic sulphate aerosol particles scatter incoming solar radiation thereby perturbing the radiative budget, hence climate. We have used a three dimensional radiative transfer model together with the sulphate concentration fields simulated by two independent chemistry-transport models to calculate the annual cycle of the radiative forcing due to anthropogenic sulphate aerosol. The calculated forcing pattern shows large peaks over the eastern United States, southeast Europe and eastern China. The calculated annual global-mean radiative forcing is -0.50 Wm-2 for Langner and Rodhe (1991) da

APA, Harvard, Vancouver, ISO, and other styles

48

Ali, Abebe Mohammed, Roshanak Darvishzadeh, Andrew Skidmore, et al. "Evaluating Prediction Models for Mapping Canopy Chlorophyll Content Across Biomes." Remote Sensing 12, no. 11 (2020): 1788. http://dx.doi.org/10.3390/rs12111788.

Full text

Abstract:

Accurate measurement of canopy chlorophyll content (CCC) is essential for the understanding of terrestrial ecosystem dynamics through monitoring and evaluating properties such as carbon and water flux, productivity, light use efficiency as well as nutritional and environmental stresses. Information on the amount and distribution of CCC helps to assess and report biodiversity indicators related to ecosystem processes and functional aspects. Therefore, measuring CCC continuously and globally from earth observation data is critical to monitor the status of the biosphere. However, generic and robu

APA, Harvard, Vancouver, ISO, and other styles

49

Marquardt Collow, Allison B., Mark A. Miller, Lynne C. Trabachino, Michael P. Jensen, and Meng Wang. "Radiative heating rate profiles over the southeast Atlantic Ocean during the 2016 and 2017 biomass burning seasons." Atmospheric Chemistry and Physics 20, no. 16 (2020): 10073–90. http://dx.doi.org/10.5194/acp-20-10073-2020.

Full text

Abstract:

Abstract. Marine boundary layer clouds, including the transition from stratocumulus to cumulus, are poorly represented in numerical weather prediction and general circulation models. Further uncertainties in the cloud structure arise in the presence of biomass burning carbonaceous aerosol, as is the case over the southeast Atlantic Ocean, where biomass burning aerosol is transported from the African continent. As the aerosol plume progresses across the southeast Atlantic Ocean, radiative heating within the aerosol layer has the potential to alter the thermodynamic environment and therefore the

APA, Harvard, Vancouver, ISO, and other styles

50

Joly, Lilian, Olivier Coopmann, Vincent Guidard, et al. "The development of the Atmospheric Measurements by Ultra-Light Spectrometer (AMULSE) greenhouse gas profiling system and application for satellite retrieval validation." Atmospheric Measurement Techniques 13, no. 6 (2020): 3099–118. http://dx.doi.org/10.5194/amt-13-3099-2020.

Full text

Abstract:

Abstract. We report in this paper the development of an embedded ultralight spectrometer (<3 kg) based on tuneable diode laser absorption spectroscopy (with a sampling rate of 24 Hz) in the mid-infrared spectral region. This instrument is dedicated to in situ measurements of the vertical profile concentrations of three main greenhouse gases – carbon dioxide (CO2), methane (CH4) and water vapour (H2O) – via standard weather and tethered balloons. The plug and play instrument is compact, robust, cost-effective, and autonomous. The instrument also has low power consumption and is non-intrusive

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!