scholarly journals Glint Removal Assessment to Estimate the Remote Sensing Reflectance in Inland Waters with Widely Differing Optical Properties

2018 ◽  
Vol 10 (10) ◽  
pp. 1655 ◽  
Author(s):  
Nariane Bernardo ◽  
Enner Alcântara ◽  
Fernanda Watanabe ◽  
Thanan Rodrigues ◽  
Alisson Carmo ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Wind Speed ◽  
In Situ Measurements ◽  
Colored Dissolved Organic Matter ◽  
The Third ◽  
Sensing Applications ◽  
Remote Sensing Reflectance ◽  
Remote Sensing Applications

The quality control of remote sensing reflectance (Rrs) is a challenging task in remote sensing applications, mainly in the retrieval of accurate in situ measurements carried out in optically complex aquatic systems. One of the main challenges is related to glint effect into the in situ measurements. Our study evaluates four different methods to reduce the glint effect from the Rrs spectra collected in cascade reservoirs with widely differing optical properties. The first (i) method adopts a constant coefficient for skylight correction (ρ) for any geometry viewing of in situ measurements and wind speed lower than 5 m·s−1; (ii) the second uses a look-up-table with variable ρ values accordingly to viewing geometry acquisition and wind speed; (iii) the third method is based on hyperspectral optimization to produce a spectral glint correction, and (iv) computes ρ as a function of wind speed. The glint effect corrected Rrs spectra were assessed using HydroLight simulations. The results showed that using the glint correction with spectral ρ achieved the lowest errors, however, in a Colored Dissolved Organic Matter (CDOM) dominated environment with no remarkable chlorophyll-a concentrations, the best method was the second. Besides, the results with spectral glint correction reduced almost 30% of errors.

Atacama Field Campaign: laboratory and in-situ measurements for remote sensing applications

2018 ◽  
Vol 12 (1) ◽  
pp. 43-61 ◽  
Author(s):  
Cristian Mattar ◽  
Andrés Santamaría-Artigas ◽  
Flavio Ponzoni ◽  
Cibele T. Pinto ◽  
Carolina Barrientos ◽  
...  
Keyword(s):  
Remote Sensing ◽  
In Situ Measurements ◽  
Field Campaign ◽  
Sensing Applications ◽  
Remote Sensing Applications

Remote sensing reflectance in the Great Lakes: In situ measurements, closure analyses, and a forward model

2013 ◽  
Vol 39 ◽  
pp. 137-150 ◽  
Author(s):  
David M. O'Donnell ◽  
Steven W. Effler ◽  
Christopher M. Strait ◽  
Feng Peng ◽  
MaryGail Perkins
Keyword(s):  
Remote Sensing ◽  
Great Lakes ◽  
In Situ Measurements ◽  
Forward Model ◽  
Remote Sensing Reflectance

scholarly journals Spatial variation of aerosol optical properties around the high-alpine site Jungfraujoch (3580 m a.s.l.)

2012 ◽  
Vol 12 (15) ◽  
pp. 7231-7249 ◽  
Author(s):  
P. Zieger ◽  
E. Kienast-Sjögren ◽  
M. Starace ◽  
J. von Bismarck ◽  
N. Bukowiecki ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Light Scattering ◽  
In Situ Measurements ◽  
Swiss Alps ◽  
Aerosol Size Distribution ◽  
Horizontal Distance ◽  
Aerosol Optical Properties ◽  
Orographic Clouds

Abstract. This paper presents results of the extensive field campaign CLACE 2010 (Cloud and Aerosol Characterization Experiment) performed in summer 2010 at the Jungfraujoch (JFJ) and the Kleine Scheidegg (KLS) in the Swiss Alps. The main goal of this campaign was to investigate the vertical variability of aerosol optical properties around the JFJ and to show the consistency of the different employed measurement techniques considering explicitly the effects of relative humidity (RH) on the aerosol light scattering. Various aerosol optical and microphysical parameters were recorded using in-situ and remote sensing techniques. In-situ measurements of aerosol size distribution, light scattering, light absorption and scattering enhancement due to water uptake were performed at the JFJ at 3580 m a.s.l.. A unique set-up allowed remote sensing measurements of aerosol columnar and vertical properties from the KLS located about 1500 m below and within the line of sight to the JFJ (horizontal distance of approx. 4.5 km). In addition, two satellite retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) and the Moderate Resolution Imaging Spectroradiometer (MODIS) as well as back trajectory analyses were added to the comparison to account for a wider geographical context. All in-situ and remote sensing measurements were in clear correspondence. The ambient extinction coefficient measured in situ at the JFJ agreed well with the KLS-based LIDAR (Light Detection and Ranging) retrieval at the altitude-level of the JFJ under plausible assumptions on the LIDAR ratio. However, we can show that the quality of this comparison is affected by orographic effects due to the exposed location of the JFJ on a saddle between two mountains and next to a large glacier. The local RH around the JFJ was often higher than in the optical path of the LIDAR measurement, especially when the wind originated from the south via the glacier, leading to orographic clouds which remained lower than the LIDAR beam. Furthermore, the dominance of long-range transported Saharan dust was observed in all measurements for several days, however only for a shorter time period in the in-situ measurements due to the vertical structure of the dust plume. The optical properties of the aerosol column retrieved from SEVIRI and MODIS showed the same magnitude and a similar temporal evolution as the measurements at the KLS and the JFJ. Remaining differences are attributed to the complex terrain and simplifications in the aerosol retrieval scheme in general.

scholarly journals Troisième atelier Trattoria consacré au transfert radiatif atmosphérique

2021 ◽  
pp. 019
Author(s):  
Philippe Dubuisson ◽  
Adrien Deschamps
Keyword(s):  
Remote Sensing ◽  
Radiative Transfer ◽  
Doctoral Students ◽  
Wavelength Range ◽  
Satellite Data ◽  
Radiation Transfer ◽  
The Third ◽  
Sensing Applications ◽  
Remote Sensing Applications ◽  
Entire Wavelength Range

Le Cnes, en collaboration avec le CNRS/Insu et Météo-France, organisait en janvier 2020 à Toulouse la troisième édition de l'atelier Trattoria (Transfert radiatif dans les atmosphères terrestres pour les observations spatiales). Cet atelier est principalement consacré aux codes de transfert radiatif dans l'atmosphère terrestre pour les applications de télédétection spatiale, opérant sur l'ensemble de la gamme des longueurs d'onde de l'ultraviolet aux micro-ondes. Ces codes numériques sont fondamentaux pour la préparation des instruments de télédétection, ainsi que pour le traitement et l'exploitation des données satellitaires. Cet atelier était ouvert à tous les chercheurs, ingénieurs, post-doctorants et doctorants du domaine. Les résultats et recommandations de l'atelier doivent servir de guide au Cnes et aux divers participants et utilisateurs français et européens de codes de transfert radiatif. The CNES, in collaboration with the CNRS/INSU and Météo-France, organized in January 2020 in Toulouse the third edition of the Trattoria workshop (Transfert radiatif dans les atmosphères terrestres pour les observations spatiales). This workshop is mainly devoted to radiation transfer codes in the Earth's atmosphere for space remote sensing applications, operating over the entire wavelength range from ultraviolet to microwaves. These numerical codes are fundamental for the preparation of remote sensing instruments, as well as for the processing and exploitation of satellite data. This workshop was open to all researchers, engineers, post-doctoral and doctoral students in the field. The results and recommendations of the workshop should serve as a "guide" for CNES and the various French and European participants and users of radiative transfer codes.

scholarly journals Spatial variation of aerosol optical properties around the high-alpine site Jungfraujoch (3580 m a.s.l.)

2012 ◽  
Vol 12 (5) ◽  
pp. 11105-11150
Author(s):  
P. Zieger ◽  
E. Kienast-Sjögren ◽  
M. Starace ◽  
J. von Bismarck ◽  
N. Bukowiecki ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Light Scattering ◽  
In Situ Measurements ◽  
Swiss Alps ◽  
Aerosol Size Distribution ◽  
Horizontal Distance ◽  
Aerosol Optical Properties ◽  
Orographic Clouds

Abstract. This paper presents results of the extensive field campaign CLACE 2010 (Cloud and Aerosol Characterization Experiment) performed in summer 2010 at the Jungfraujoch (JFJ) and the Kleine Scheidegg (KLS) in the Swiss Alps. The main goal of this campaign was to investigate the vertical variability of aerosol optical properties around the JFJ and to show the consistency of the different employed measurement techniques considering explicitly the effects of relative humidity (RH) on the aerosol light scattering. Various aerosol optical and microphysical parameters were recorded using in-situ and remote sensing techniques. In-situ measurements of aerosol size distribution, light scattering, light absorption and scattering enhancement due to water uptake were performed at the JFJ at 3580 m (a.s.l.). A unique set-up allowed remote sensing measurements of aerosol columnar and vertical properties from the KLS located about 1500 m below and within the line of sight to the JFJ (horizontal distance of approx. 4.5 km). In addition, two satellite retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) and the Moderate Resolution Imaging Spectroradiometer (MODIS) as well as back trajectory analyses were added to the comparison to account for a wider geographical context. All in-situ and remote sensing measurements were in clear correspondence. The ambient extinction coefficient measured in-situ at the JFJ agreed well with the KLS-based LIDAR (Light Detection and Ranging) retrieval at the altitude-level of the JFJ under plausible assumptions on the LIDAR ratio. However, we can show that the quality of this comparison is affected by orographic effects due to the exposed location of the JFJ on a saddle between two mountains and next to a large glacier. The local RH around the JFJ was often higher than in the optical path of the LIDAR measurement, especially when the wind originated from the south via the glacier, leading to orographic clouds which remained lower than the LIDAR beam. Furthermore, the dominance of long-range transported Saharan dust was observed in all measurements for several days, however only for a shorter time period in the in-situ measurements due to the vertical structure of the dust plume. The optical properties of the aerosol column retrieved from SEVIRI and MODIS showed the same magnitude and a similar temporal evolution as the measurements at the KLS and the JFJ. Remaining differences are attributed to the complex terrain and simplifications in the aerosol retrieval scheme in general.

scholarly journals In situ determination of the remote sensing reflectance: an inter-comparison

Ocean Science ◽  
2012 ◽  
Vol 8 (4) ◽  
pp. 567-586 ◽  
Author(s):  
G. Zibordi ◽  
K. Ruddick ◽  
I. Ansko ◽  
G. Moore ◽  
S. Kratzer ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Sensors ◽  
Optical Systems ◽  
Radiometric Calibration ◽  
Northern Adriatic ◽  
Sensing Applications ◽  
Remote Sensing Reflectance ◽  
Data Products ◽  
Relative Differences

Abstract. Inter-comparison of data products from simultaneous measurements performed with independent systems and methods is a viable approach to assess the consistency of data and additionally to investigate uncertainties. Within such a context the inter-comparison called Assessment of In Situ Radiometric Capabilities for Coastal Water Remote Sensing Applications (ARC) was carried out at the Acqua Alta Oceanographic Tower in the northern Adriatic Sea to explore the accuracy of in situ data products from various in- and above-water optical systems and methods. Measurements were performed under almost ideal conditions, including a stable deployment platform, clear sky, relatively low sun zenith angles and moderately low sea state. Additionally, all optical sensors involved in the experiment were inter-calibrated through absolute radiometric calibration performed with the same standards and methods. Inter-compared data products include spectral water-leaving radiance Lw (λ), above-water downward irradiance Ed(0+,λ) and remote sensing reflectance Rrs(λ). Data products from the various measurement systems/methods were directly compared to those from a single reference system/method. Results for Rrs(λ) indicate spectrally averaged values of relative differences comprised between −1 and +6%, while spectrally averaged values of absolute differences vary from approximately 6% for the above-water systems/methods to 9% for buoy-based systems/methods. The agreement between Rrs(λ) spectral relative differences and estimates of combined uncertainties of the inter-compared systems/methods is noteworthy.

Bulk Scattering Properties for the Remote Sensing of Ice Clouds. Part I: Microphysical Data and Models

2005 ◽  
Vol 44 (12) ◽  
pp. 1885-1895 ◽  
Author(s):  
Bryan A. Baum ◽  
Andrew J. Heymsfield ◽  
Ping Yang ◽  
Sarah T. Bedka
Keyword(s):  
Remote Sensing ◽  
Particle Size ◽  
In Situ Measurements ◽  
Two Dimensional ◽  
Cloud Particle ◽  
Ice Clouds ◽  
Sensing Applications ◽  
Airborne Sampling ◽  
Bulk Scattering

Abstract This study reports on the use of in situ data obtained in midlatitude and tropical ice clouds from airborne sampling probes and balloon-borne replicators as the basis for the development of bulk scattering models for use in satellite remote sensing applications. Airborne sampling instrumentation includes the two-dimensional cloud (2D-C), two-dimensional precipitation (2D-P), high-volume precipitation spectrometer (HVPS), cloud particle imager (CPI), and NCAR video ice particle sampler (VIPS) probes. Herein the development of a comprehensive set of microphysical models based on in situ measurements of particle size distributions (PSDs) is discussed. Two parameters are developed and examined: ice water content (IWC) and median mass diameter Dm. Comparisons are provided between the IWC and Dm values derived from in situ measurements obtained during a series of field campaigns held in the midlatitude and tropical regions and those calculated from a set of modeled ice particles used for light-scattering calculations. The ice particle types considered in this study include droxtals, hexagonal plates, solid columns, hollow columns, aggregates, and 3D bullet rosettes. It is shown that no single habit accurately replicates the derived IWC and Dm values, but a mixture of habits can significantly improve the comparison of these bulk microphysical properties. In addition, the relationship between Dm and the effective particle size Deff, defined as 1.5 times the ratio of ice particle volume to projected area for a given PSD, is investigated. Based on these results, a subset of microphysical models is chosen as the basis for the development of ice cloud bulk scattering models in Part II of this study.

Sign in / Sign up

Export Citation Format

Share Document