in the window region, but values larger than total measurement uncertainties in the far infrared.... more in the window region, but values larger than total measurement uncertainties in the far infrared. Possible causes are investigated. It is shown that the uncertainties related to the water vapour and temperature profiles are of the same order as the sensitivity to the a priori assumption on particle habits for an up-looking configuration. In case of a down-looking configuration, errors due to possible incorrect description of the water vapour profile would be drastically reduced.
Marine resources, representing one of the most significant of the Earth, deserve monitoring syste... more Marine resources, representing one of the most significant of the Earth, deserve monitoring systems able to provide reliable and frequently updated information about their status and evolution. An integrated approach, based on the combination of in situ measurements, satellite observations and specific models, can represent the most adequate solution for such kind of systems. In this framework, the RITMARE Project, the wider Italian project on marine environment research, funded by the Italian Ministry of Education University and Researchcontemplates, among its main objectives, the development and integration of advanced data analysis techniques of satellite and in-situ measurements. In this framework several in-situ measurements campaigns have been performed by Unmanned Marine Vehicles (UMV) and results achieved compared with satellite based products. In this paper, preliminarily results achieved during the campaign UMV measurement campaign carried out on 29 october 2103 in the Naples Gulf are presented and results compared with EOS/MODIS products in order to demonstrate the added value of the combined use of in-situ and remote observations for coastal water monitoring and marine environment protection.
1] A comparison of radiative transfer models for simulating radiances from the Atmospheric Infrar... more 1] A comparison of radiative transfer models for simulating radiances from the Atmospheric Infrared Sounder (AIRS), has been undertaken. Results from 14 line-by-line and fast parameterized infrared models were submitted. Several aspects of the models were compared. First, the forward model calculations for all 2378 AIRS channels for 52 diverse atmospheric profiles and one tropical Pacific profile coincident with AIRS data were performed for three local zenith viewing angles: nadir, 45, and 60 degrees. Second, for a subset of the models and only 20 AIRS channels the transmittances from each layer to space were provided. Finally, for some models the Jacobians with respect to temperature, water vapor, and ozone were also computed. For the forward model calculations, most models agree to within 0.02 K when compared to a reference lineby-line model averaged over a subset of profiles, with the exception of a few spectral regions. When compared with AIRS observations, however, the mean differences increase to 0.2 K, and for a few models even greater differences are seen. The transmittance differences highlighted regions of the spectrum where the spectroscopy of the models differs, particularly in the carbon dioxide absorption bands at 667 cm À1 and 2386 cm À1 . For the Jacobians all models have some profiles/channels that do not fit the reference well, and the main problems are documented here. The model differences only increase slightly for off-nadir viewing angles for both forward and Jacobian calculations.
There is a growing interest in the far infrared spectral region 17–50μm as a remote sensing tool ... more There is a growing interest in the far infrared spectral region 17–50μm as a remote sensing tool in atmospheric sciences, since this portion of the spectrum contains the characteristic molecular rotational band for water vapour. Much of the Earth energy lost to space is radiated through this spectral region. The Radiation Explorer in the Far InfraRed Breadboard (REFIR/BB) spectrometer was
Estuaries and coastal zones are very dynamic and complex ecosystems which deserve multi-scale and... more Estuaries and coastal zones are very dynamic and complex ecosystems which deserve multi-scale and multi-disciplinary monitoring system. IOnian Sea water quality MOnitoring by Satellite data (IOSMOS) is a European Transnational Cooperation co-financed by the Operational Program ERDF Basilicata 2007-2013, with the main aim of supporting Basilicata Region (South of Italy) in monitoring Ionian sea water quality status by developing advanced satellite data products. By implementing a general methodology for multi-temporal satellite data analysis, the Robust Satellite Techniques (RST) approach on more than 10 years of satellite data/products, the project aims at providing a description of the sea water status in terms of standard bio-optical parameters, such as Chlorophyll-a (Chl-a) and Coloured Dissolved Organic Matter (CDOM). The suspended sediment material (SSM) transport phenomena occurring in the area and the Sea Surface Temperature (SST) variations will be also investigated. In addition, by performing specific in situ and airborne measurement campaigns, a calibration at local scale of satellite standard products will be implemented, assessing also the opportunity to develop original products. In this paper, main activities of the projects and results of first campaigns will be presented and discussed.
ABSTRACT A solution of the mean spherical model is presented for particles interacting with a pai... more ABSTRACT A solution of the mean spherical model is presented for particles interacting with a pair potential which is repulsive at short-range and attractive at long-range. The solution can be used for the description of the structure of strongly-coupled dusty plasmas, represented as one component systems of dust particles with an interaction potential determined by the plasma dynamics; a screened Coulomb repulsive interaction at short distances and a long-range attraction due to a screened ``shadow effect'' on the plasma fluxes to the dust particles. A comparison with recent experimental results shows a better agreement when the attractive potential is present.
Remote Sensing of Clouds and the Atmosphere V, 2001
The Infrared Atmospheric Sounding Interferometer (IASI) has 8461 potential channels to be exploit... more The Infrared Atmospheric Sounding Interferometer (IASI) has 8461 potential channels to be exploited for inversions of geophysical parameters. In this paper we analyse two different strategies for their reduction. The first one looks for suitable spectral ranges where the inverse problem is as linear as possible; the second one is based on the cluster analysis theory. Our aim is to minimise the potential information loss evaluated by directly comparing the retrieved temperature and water vapour profiles on a complete set of test atmospheres.
Remote Sensing of Clouds and the Atmosphere V, 2001
ABSTRACT In this paper, we present an analytical scheme for the computation of Hessian for skin t... more ABSTRACT In this paper, we present an analytical scheme for the computation of Hessian for skin temperature, temperature profile and water vapor profile. It is possible to retrieve atmospheric parameters from IR radiance achieving the quadratic convergence for a pure Newton algorithm.
Remote Sensing of Clouds and the Atmosphere VI, 2002
Correlation interferometry is a particular application of Fourier transform spectroscopy with par... more Correlation interferometry is a particular application of Fourier transform spectroscopy with partially scanned interferograms. Basically, it is a technique to obtain the difference between the spectra of atmospheric radiance at two diverse spectral resolutions. Although the technique could be exploited to design an appropriate correlation interferometer, in this paper we are concerned with the analytical aspects of the method and its application to high-spectral-resolution infrared observations in order to separate the emission of a given atmospheric gas from a spectral signal dominated by surface emission, such as in the case of satellite spectrometers operated in the nadir looking mode. The tool will be used to address some basic questions concerning the vertical spatial resolution of H 2 O and to develop an algorithm to retrieve the columnar amount of CO 2 . An application to complete interferograms from the Infrared Atmospheric Sounding Interferometer will be presented and discussed. For H 2 O, we have concluded that the vertical spatial resolution in the lower troposphere mostly depends on broad features associated with the spectrum, whereas for CO 2 , we have derived a technique capable of retrieving a CO 2 columnar amount with accuracy of ≈ AE 7 parts per million by volume at the level of each single field of view.
In this paper, we present a new methodology for the simultaneous retrieval of surface and atmosph... more In this paper, we present a new methodology for the simultaneous retrieval of surface and atmospheric parameters of Mars. The methodology is essentially based on similar codes implemented for high-resolution instruments looking at Earth, supported by a statistical retrieval procedure used to initialize the physical retrieval algorithm with a reliable first guess of the atmospheric parameters. The methodology has been customized for the Thermal Emission Spectrometer (TES), which is a low-resolution interferometer. However, with minor changes to the forward and inverse modules, it is applicable to any instrument looking at Mars, and with particular effectiveness to high-resolution instruments. The forward module is a monochromatic radiative transfer model with the capability to calculate analytical Jacobians of any desired geophysical parameter. In the present work, we describe the general methodology and its application to a large sample of TES spectra. Results are drawn for the case...
Remote Sensing of Clouds and the Atmosphere XII, 2007
Direct solar irradiance and IR atmospheric radiance have been measured during different measureme... more Direct solar irradiance and IR atmospheric radiance have been measured during different measurements campaigns, conducted in three mountain sites in Italy, far from anthropogenic sources. Direct solar irradiance has been measured by a high resolution (1.5 nm) AVANTES radiometer, working in the spectral range 400 nm-900 nm, while down welling IR sky radiance measurements has been measured by an MR100 BOMEM Fourier Transform Spectrometer covering the spectral ranges 500 cm-1-5000 cm-1 and 1 cm-1 of resolution. At least two Radiosonde launches per day furnished temperature and water vapour profiles. The instruments were located on a mobile laboratory, specifically projected to host them. The parameters obtained from direct solar irradiance are Aerosol Optical Depth, Angstrom parameters and Aerosol Size Distributions retrieval, while from IR data water vapour and temperature profiles have been retrieved. Different orographic characteristics and different air-masses circulation on the measurement sites influenced Aerosol Optical Depth values and variation. Infrared radiances inversion allows the water vapour content retrieval and a correlation between aerosol effective radii and water vapour content has been looked for.
Remote Sensing of Clouds and the Atmosphere VII, 2003
In this work we describe a methodology for the inclusion of first-order water vapor self-broadeni... more In this work we describe a methodology for the inclusion of first-order water vapor self-broadening effects in look-up-table based radiative transfer calculations. The methodology does not increase the complexity and size of look-up-tables which continue to exist in a 1-D setting, although the inclusion of a new variable (i.e., the water vapor concentration) would raise the dimensionality to 2-D. The scheme is discussed for modern infrared sensors whose spectral resolution falls in the range 0.1 - 2 cm-1.
Fourier Transform Spectroscopy/ Hyperspectral Imaging and Sounding of the Environment, 2005
New generation meteorological satellites carry infrared sensors able to sense the earth emission ... more New generation meteorological satellites carry infrared sensors able to sense the earth emission spectrum at very high spectral resolution. The related problems of cloud detection and inversion for geophysical parameters are addressed in this paper.
It is shown that IMG (interferometric monitoring of greenhouse gases) spectra recorded over Afric... more It is shown that IMG (interferometric monitoring of greenhouse gases) spectra recorded over African and Arabian deserts clearly contain the fingerprint of quartz-rich soils. We illustrate how this spectral signature can be exploited to devise a suitable cloud-detection scheme to identify which infrared observations are affected by clouds. As a by-product, the scheme also allows one to identify the most likely underlying emitting surface type and provides a suitable first guess for the surface emissivity to be used, e.g., for the retrieval of geophysical parameters from high-spectral-resolution infrared radiance from space. The analysis has focused on African deserts because of their intrinsic relevance to numerical weather prediction and Earth's climate. Desert areas, like oceans, are poorly covered by the world meteorological radiosonde network and therefore are geographical regions for which the global coverage capability of satellites soundings is expected to provide better i...
The sensitivity of a new algorithm for cloud detection over a sea surface has been assessed on th... more The sensitivity of a new algorithm for cloud detection over a sea surface has been assessed on the basis of extensive simulations of clear and cloudy radiance spectra, including water and ice and low- and high-altitude clouds. The new algorithm makes use of autocorrelation and cross correlation between an observed spectrum and either a synthetic or a laboratory spectrum and can be used to determine quantitatively the degree of homogeneity of two spectra in the 800-900-cm(-1) region (11.11-12.5 microm). The scheme is intended for high-spectral-resolution observations and could form the basis for an operational stand-alone cloud-detection algorithm for next-generation sounding spectrometers. Application of the scheme to real observations is presented and discussed.
We introduce a classification method (Cumulative Discriminant Analysis) of the Discriminant Analy... more We introduce a classification method (Cumulative Discriminant Analysis) of the Discriminant Analysis type to discriminate between cloudy and clear sky satellite observations in the thermal infrared. The tool is intended for the high spectral resolution infrared sounder (IRS) planned for the geostationary METEOSAT (Meteorological Satel-5 15 vanced Very High Resolution Radiometer) and SEVIRI (Spinning Enhanced Visible and Infrared Imager) imagers. The agreement with these independent cloud masks is generally well above 80 %, except at high latitudes in their winter seasons.
in the window region, but values larger than total measurement uncertainties in the far infrared.... more in the window region, but values larger than total measurement uncertainties in the far infrared. Possible causes are investigated. It is shown that the uncertainties related to the water vapour and temperature profiles are of the same order as the sensitivity to the a priori assumption on particle habits for an up-looking configuration. In case of a down-looking configuration, errors due to possible incorrect description of the water vapour profile would be drastically reduced.
Marine resources, representing one of the most significant of the Earth, deserve monitoring syste... more Marine resources, representing one of the most significant of the Earth, deserve monitoring systems able to provide reliable and frequently updated information about their status and evolution. An integrated approach, based on the combination of in situ measurements, satellite observations and specific models, can represent the most adequate solution for such kind of systems. In this framework, the RITMARE Project, the wider Italian project on marine environment research, funded by the Italian Ministry of Education University and Researchcontemplates, among its main objectives, the development and integration of advanced data analysis techniques of satellite and in-situ measurements. In this framework several in-situ measurements campaigns have been performed by Unmanned Marine Vehicles (UMV) and results achieved compared with satellite based products. In this paper, preliminarily results achieved during the campaign UMV measurement campaign carried out on 29 october 2103 in the Naples Gulf are presented and results compared with EOS/MODIS products in order to demonstrate the added value of the combined use of in-situ and remote observations for coastal water monitoring and marine environment protection.
1] A comparison of radiative transfer models for simulating radiances from the Atmospheric Infrar... more 1] A comparison of radiative transfer models for simulating radiances from the Atmospheric Infrared Sounder (AIRS), has been undertaken. Results from 14 line-by-line and fast parameterized infrared models were submitted. Several aspects of the models were compared. First, the forward model calculations for all 2378 AIRS channels for 52 diverse atmospheric profiles and one tropical Pacific profile coincident with AIRS data were performed for three local zenith viewing angles: nadir, 45, and 60 degrees. Second, for a subset of the models and only 20 AIRS channels the transmittances from each layer to space were provided. Finally, for some models the Jacobians with respect to temperature, water vapor, and ozone were also computed. For the forward model calculations, most models agree to within 0.02 K when compared to a reference lineby-line model averaged over a subset of profiles, with the exception of a few spectral regions. When compared with AIRS observations, however, the mean differences increase to 0.2 K, and for a few models even greater differences are seen. The transmittance differences highlighted regions of the spectrum where the spectroscopy of the models differs, particularly in the carbon dioxide absorption bands at 667 cm À1 and 2386 cm À1 . For the Jacobians all models have some profiles/channels that do not fit the reference well, and the main problems are documented here. The model differences only increase slightly for off-nadir viewing angles for both forward and Jacobian calculations.
There is a growing interest in the far infrared spectral region 17–50μm as a remote sensing tool ... more There is a growing interest in the far infrared spectral region 17–50μm as a remote sensing tool in atmospheric sciences, since this portion of the spectrum contains the characteristic molecular rotational band for water vapour. Much of the Earth energy lost to space is radiated through this spectral region. The Radiation Explorer in the Far InfraRed Breadboard (REFIR/BB) spectrometer was
Estuaries and coastal zones are very dynamic and complex ecosystems which deserve multi-scale and... more Estuaries and coastal zones are very dynamic and complex ecosystems which deserve multi-scale and multi-disciplinary monitoring system. IOnian Sea water quality MOnitoring by Satellite data (IOSMOS) is a European Transnational Cooperation co-financed by the Operational Program ERDF Basilicata 2007-2013, with the main aim of supporting Basilicata Region (South of Italy) in monitoring Ionian sea water quality status by developing advanced satellite data products. By implementing a general methodology for multi-temporal satellite data analysis, the Robust Satellite Techniques (RST) approach on more than 10 years of satellite data/products, the project aims at providing a description of the sea water status in terms of standard bio-optical parameters, such as Chlorophyll-a (Chl-a) and Coloured Dissolved Organic Matter (CDOM). The suspended sediment material (SSM) transport phenomena occurring in the area and the Sea Surface Temperature (SST) variations will be also investigated. In addition, by performing specific in situ and airborne measurement campaigns, a calibration at local scale of satellite standard products will be implemented, assessing also the opportunity to develop original products. In this paper, main activities of the projects and results of first campaigns will be presented and discussed.
ABSTRACT A solution of the mean spherical model is presented for particles interacting with a pai... more ABSTRACT A solution of the mean spherical model is presented for particles interacting with a pair potential which is repulsive at short-range and attractive at long-range. The solution can be used for the description of the structure of strongly-coupled dusty plasmas, represented as one component systems of dust particles with an interaction potential determined by the plasma dynamics; a screened Coulomb repulsive interaction at short distances and a long-range attraction due to a screened ``shadow effect'' on the plasma fluxes to the dust particles. A comparison with recent experimental results shows a better agreement when the attractive potential is present.
Remote Sensing of Clouds and the Atmosphere V, 2001
The Infrared Atmospheric Sounding Interferometer (IASI) has 8461 potential channels to be exploit... more The Infrared Atmospheric Sounding Interferometer (IASI) has 8461 potential channels to be exploited for inversions of geophysical parameters. In this paper we analyse two different strategies for their reduction. The first one looks for suitable spectral ranges where the inverse problem is as linear as possible; the second one is based on the cluster analysis theory. Our aim is to minimise the potential information loss evaluated by directly comparing the retrieved temperature and water vapour profiles on a complete set of test atmospheres.
Remote Sensing of Clouds and the Atmosphere V, 2001
ABSTRACT In this paper, we present an analytical scheme for the computation of Hessian for skin t... more ABSTRACT In this paper, we present an analytical scheme for the computation of Hessian for skin temperature, temperature profile and water vapor profile. It is possible to retrieve atmospheric parameters from IR radiance achieving the quadratic convergence for a pure Newton algorithm.
Remote Sensing of Clouds and the Atmosphere VI, 2002
Correlation interferometry is a particular application of Fourier transform spectroscopy with par... more Correlation interferometry is a particular application of Fourier transform spectroscopy with partially scanned interferograms. Basically, it is a technique to obtain the difference between the spectra of atmospheric radiance at two diverse spectral resolutions. Although the technique could be exploited to design an appropriate correlation interferometer, in this paper we are concerned with the analytical aspects of the method and its application to high-spectral-resolution infrared observations in order to separate the emission of a given atmospheric gas from a spectral signal dominated by surface emission, such as in the case of satellite spectrometers operated in the nadir looking mode. The tool will be used to address some basic questions concerning the vertical spatial resolution of H 2 O and to develop an algorithm to retrieve the columnar amount of CO 2 . An application to complete interferograms from the Infrared Atmospheric Sounding Interferometer will be presented and discussed. For H 2 O, we have concluded that the vertical spatial resolution in the lower troposphere mostly depends on broad features associated with the spectrum, whereas for CO 2 , we have derived a technique capable of retrieving a CO 2 columnar amount with accuracy of ≈ AE 7 parts per million by volume at the level of each single field of view.
In this paper, we present a new methodology for the simultaneous retrieval of surface and atmosph... more In this paper, we present a new methodology for the simultaneous retrieval of surface and atmospheric parameters of Mars. The methodology is essentially based on similar codes implemented for high-resolution instruments looking at Earth, supported by a statistical retrieval procedure used to initialize the physical retrieval algorithm with a reliable first guess of the atmospheric parameters. The methodology has been customized for the Thermal Emission Spectrometer (TES), which is a low-resolution interferometer. However, with minor changes to the forward and inverse modules, it is applicable to any instrument looking at Mars, and with particular effectiveness to high-resolution instruments. The forward module is a monochromatic radiative transfer model with the capability to calculate analytical Jacobians of any desired geophysical parameter. In the present work, we describe the general methodology and its application to a large sample of TES spectra. Results are drawn for the case...
Remote Sensing of Clouds and the Atmosphere XII, 2007
Direct solar irradiance and IR atmospheric radiance have been measured during different measureme... more Direct solar irradiance and IR atmospheric radiance have been measured during different measurements campaigns, conducted in three mountain sites in Italy, far from anthropogenic sources. Direct solar irradiance has been measured by a high resolution (1.5 nm) AVANTES radiometer, working in the spectral range 400 nm-900 nm, while down welling IR sky radiance measurements has been measured by an MR100 BOMEM Fourier Transform Spectrometer covering the spectral ranges 500 cm-1-5000 cm-1 and 1 cm-1 of resolution. At least two Radiosonde launches per day furnished temperature and water vapour profiles. The instruments were located on a mobile laboratory, specifically projected to host them. The parameters obtained from direct solar irradiance are Aerosol Optical Depth, Angstrom parameters and Aerosol Size Distributions retrieval, while from IR data water vapour and temperature profiles have been retrieved. Different orographic characteristics and different air-masses circulation on the measurement sites influenced Aerosol Optical Depth values and variation. Infrared radiances inversion allows the water vapour content retrieval and a correlation between aerosol effective radii and water vapour content has been looked for.
Remote Sensing of Clouds and the Atmosphere VII, 2003
In this work we describe a methodology for the inclusion of first-order water vapor self-broadeni... more In this work we describe a methodology for the inclusion of first-order water vapor self-broadening effects in look-up-table based radiative transfer calculations. The methodology does not increase the complexity and size of look-up-tables which continue to exist in a 1-D setting, although the inclusion of a new variable (i.e., the water vapor concentration) would raise the dimensionality to 2-D. The scheme is discussed for modern infrared sensors whose spectral resolution falls in the range 0.1 - 2 cm-1.
Fourier Transform Spectroscopy/ Hyperspectral Imaging and Sounding of the Environment, 2005
New generation meteorological satellites carry infrared sensors able to sense the earth emission ... more New generation meteorological satellites carry infrared sensors able to sense the earth emission spectrum at very high spectral resolution. The related problems of cloud detection and inversion for geophysical parameters are addressed in this paper.
It is shown that IMG (interferometric monitoring of greenhouse gases) spectra recorded over Afric... more It is shown that IMG (interferometric monitoring of greenhouse gases) spectra recorded over African and Arabian deserts clearly contain the fingerprint of quartz-rich soils. We illustrate how this spectral signature can be exploited to devise a suitable cloud-detection scheme to identify which infrared observations are affected by clouds. As a by-product, the scheme also allows one to identify the most likely underlying emitting surface type and provides a suitable first guess for the surface emissivity to be used, e.g., for the retrieval of geophysical parameters from high-spectral-resolution infrared radiance from space. The analysis has focused on African deserts because of their intrinsic relevance to numerical weather prediction and Earth's climate. Desert areas, like oceans, are poorly covered by the world meteorological radiosonde network and therefore are geographical regions for which the global coverage capability of satellites soundings is expected to provide better i...
The sensitivity of a new algorithm for cloud detection over a sea surface has been assessed on th... more The sensitivity of a new algorithm for cloud detection over a sea surface has been assessed on the basis of extensive simulations of clear and cloudy radiance spectra, including water and ice and low- and high-altitude clouds. The new algorithm makes use of autocorrelation and cross correlation between an observed spectrum and either a synthetic or a laboratory spectrum and can be used to determine quantitatively the degree of homogeneity of two spectra in the 800-900-cm(-1) region (11.11-12.5 microm). The scheme is intended for high-spectral-resolution observations and could form the basis for an operational stand-alone cloud-detection algorithm for next-generation sounding spectrometers. Application of the scheme to real observations is presented and discussed.
We introduce a classification method (Cumulative Discriminant Analysis) of the Discriminant Analy... more We introduce a classification method (Cumulative Discriminant Analysis) of the Discriminant Analysis type to discriminate between cloudy and clear sky satellite observations in the thermal infrared. The tool is intended for the high spectral resolution infrared sounder (IRS) planned for the geostationary METEOSAT (Meteorological Satel-5 15 vanced Very High Resolution Radiometer) and SEVIRI (Spinning Enhanced Visible and Infrared Imager) imagers. The agreement with these independent cloud masks is generally well above 80 %, except at high latitudes in their winter seasons.
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Papers by Guido Masiello