MICHAL SHIMONI - Academia.edu (original) (raw)

Papers by MICHAL SHIMONI

Research paper thumbnail of Spectral Monitoring of Algal Blooms in an Eutrophic Lake Using Sentinel-2

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium

Eutrophication is a process in which elevated organic matter and nutrients raises the primary pro... more Eutrophication is a process in which elevated organic matter and nutrients raises the primary production of a water body. As a result, the productivity of phytoplankton and biomass are very high at all trophic levels. During bloom event, the spatial and temporal distribution of this phenomena is difficult to be observed using conventional water sampling methods. This work advance the state of the art by using Sentinel-2 (S2) images to estimate chlorophyll-a (chl-a) concentration with an empirical model. Specifically, the model uses band 8 (NIR) and band 4 (red) to predict chl-a concentration during an algal bloom event in San Roque lake, Córdoba, Argentina. Nevertheless, novel spectral ratio for algae composition patterns has also been created using bands 8a and 9. The results show that S2 has the potential to monitor bloom events in eutrophic lakes.

Research paper thumbnail of The GEPATAR project: GEotechnical and Patrimonial Archives Toolbox for ARchitectural conservation in Belgium

EGU General Assembly Conference Abstracts, Apr 1, 2018

Research paper thumbnail of Advancing the retrievals of surface emissivity by modelling the spatial distribution of temperature in the thermal hyperspectral scene

Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XXII, 2016

Land Surface Temperature (LST) and Land Surface Emissivity (LSE) are commonly retrieved from ther... more Land Surface Temperature (LST) and Land Surface Emissivity (LSE) are commonly retrieved from thermal hyperspectral imaging. However, their retrieval is not a straightforward procedure because the mathematical problem is ill-posed. This procedure becomes more challenging in an urban area where the spatial distribution of temperature varies substantially in space and time. For assessing the influence of several spatial variances on the deviation of the temperature in the scene, a statistical model is created. The model was tested using several images from various times in the day and was validated using in-situ measurements. The results highlight the importance of the geometry of the scene and its setting relative to the position of the sun during day time. It also shows that when the position of the sun is in zenith, the main contribution to the thermal distribution in the scene is the thermal capacity of the landcover materials. In this paper we propose a new Temperature and Emissivity Separation (TES) method which integrates 3D surface and landcover information from LIDAR and VNIR hyperspectral imaging data in an attempt to improve the TES procedure for a thermal hyperspectral scene. The experimental results prove the high accuracy of the proposed method in comparison to another conventional TES model.

Research paper thumbnail of The independent service validation in GMES RESPOND: the flood validation exercise

International Journal of Digital Earth, 2011

ABSTRACT This article is aimed at providing a detailed description of the Flood Validation Exerci... more ABSTRACT This article is aimed at providing a detailed description of the Flood Validation Exercise organised by the Independent Service Validation Group of the Global Monitoring for Environment and Security (GMES) RESPOND project. The aims of the validation exercise were: (1) providing a practical example of validation procedures in the frame of the GMES Emergency Response services; (2) executing a full-scale validation exercise able to cope with the requirements of an emergency service; and (3) better understanding the performances and limitations of Earth observation services for Flood Damage Mapping. This validation exercise is a first step of the main task to define the whole validation process for GMES services. When this is achieved, there will be knowledge concerning how well services meet the service specifications derived from the user needs. The present exercise has the purpose of gathering this knowledge. The output of this validation exercise can be used to characterise and qualify the performance and timeliness of Crisis and Damage Mapping Services. This paper summarises the methodology for the flood exercise validation and the results of product validation and inter-comparison.

Research paper thumbnail of <title>Quality of topographic data from interferometry SAR DEM for hydrological researches: The case study of the Lesse and the Dendre rivers, Belgium</title>

Remote Sensing for Agriculture, Ecosystems, and Hydrology III, 2002

For hydrology and terrestrial ecosystem studies, topography has a significant influence on the am... more For hydrology and terrestrial ecosystem studies, topography has a significant influence on the amount of intercepted solar radiation, the surface and sub-surface water movements, the type and distribution of vegetation and the microclimate. Processing Digital Elevation Model (DEM) data to extract hydrological features becomes a routine, but the numerous DEMs available stress the importance of their quality assessment. Radar interferometry (InSAR) technique is a promising approach to generate digital elevation models. The goal of this research is to verify to what extend the InSAR DEM can be used as a topographic database for deriving hydrological informations. This study was realised over the Dendre and the Lesse watersheds. Because DEM quality cannot be determined by a single criterion, the quality assessment should be application oriented. In this study, the NGI (National Geographic Institute of Belgium) DEM was chosen as a topographic reference for the quality assessment of the InSAR DEMs. The Root Mean Square (RMS) of the altitude difference between the NGI and the InSAR DEM was used as general quality measurement. The mean slope value has been calculated to characterise the relief of the basin. For both of the basins, watershed borders and hydrographic network were generated with GIS technique. The results obtained were compared between them and with digitised hydrographic network. Hydrographic network derived from InSAR DEM was not found accurate enough in flat wide valley. For the studied areas, the InSAR DEMs are precise enough for large-scale hydrological investigation where information like watershed border or relief is needed. However, InSAR DEMs is not suitable for hydraulic models, because they require extreme accuracy.

Research paper thumbnail of Treaty Monitoring

Remote Sensing from Space, 2009

... of satellite imagery as an essential part of the nuclear safeguards system of the Internation... more ... of satellite imagery as an essential part of the nuclear safeguards system of the International Atomic Energy Agency (IAEA) is a good example of MTM. ... The NPT related activities can essentially be broken down into three phases: 1. Operation 2. Shut-down 3. De-commission Fig. ...

Research paper thumbnail of The comparability of aggregated emissivity and temperature of heterogeneous pixel to conventional tes methods

2013 5th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), 2013

Unmixing in the reflective domain is a well known technique to retrieve materials and their abund... more Unmixing in the reflective domain is a well known technique to retrieve materials and their abundances from hyperspectral imaging scene. However, for the thermal domain (8–14 μm) only few unmixing models were developed due to the complexity of retrieving three unknowns (i.e. materials abundance, temperature and emissivity) from the pixel radiance. Attempt to solve this complexity is using aggregation models. The aggregation models are physics based models which estimate the pixel radiance with the contribution of acquisition parameters and scene description including the temperature and the emissivity of materials. This paper focuses on the comparison of temperature / emissivity estimated using inhouse aggregation model with two conventional Temperature and Emissivity Separation (TES) methods: Maximum Minimum Differences (MMD/TES) and SPectral SMoothness method (SpSm). This comparison is achieved using synthetic mixed pixels of two sensors AHS-160 and SEBASS. The results show that b...

Research paper thumbnail of Urban features classification using 3D hyperspectral data

2013 5th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), 2013

The surface classification of heterogeneous urban areas can be refined using the integration of s... more The surface classification of heterogeneous urban areas can be refined using the integration of spectral and 3D information. However, pixel-classification based fusion requires semi-pixel geo-registration accuracy. In this paper the 3D information is obtained from the hyperspectral data set itself. This study presents an adaptation of optimized MRF based stereo matching for the creation of 3D scenes using hyperspectral data. The obtained 3D information is integrated into a SVM classifier procedure. The results obtained in this study show the potential in the creation of 3D scenes using hyperspectral data and the benefit of combining this data with spectral information for better classification of the urban materials.

Research paper thumbnail of Analysis of the unmixing on thermal hyperspectral imaging

Research paper thumbnail of Airborne hyperspectral potential for coastal biogeochemistry of the Scheldt estuary and plume

Research paper thumbnail of Detection of vehicles in shadow areas using combined hyperspectral and lidar data

2011 IEEE International Geoscience and Remote Sensing Symposium, 2011

ABSTRACT In an effort to overcome the limitations of small target detection in complex urban scen... more ABSTRACT In an effort to overcome the limitations of small target detection in complex urban scene, complementary data sets are combined to provide additional insight about a particular scene. This paper presents a method based on shape/spectral integration (SSI) decision level fusion algorithm to improve the detection of vehicles in semi and deep shadow areas. A four steps process combines high resolution LIDAR and hyperspectral data to classify shadow areas, segment vehicles in LIDAR data, detect spectral anomalies and improves vehicle detection. The SSI decision level fusion algorithm was shown to outperform detection using a single data set and the utility of shape information was shown to be a way to enhance spectral target detection in complex urban scenes.

Research paper thumbnail of Detection of occluded targets using thermal imaging spectroscopy

2010 2nd Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, 2010

Automatic detection of occluded targets from a sequence of images is an interesting area of resea... more Automatic detection of occluded targets from a sequence of images is an interesting area of research for defense related application. In this paper, change detection methods are investigated for the detection of buried improvised explosive devices (IED) using temporal thermal hyperspectral scenes. Specifically, the paper assesses the detection of buried small aluminium plates using the TELOPS Hyper-Cam sensor and by

Research paper thumbnail of Fusion of PolSAR and PolInSAR data for land cover classification

International Journal of Applied Earth Observation and Geoinformation, 2009

Research paper thumbnail of <title>Supervised classification of hyperspectral images using a combination of spectral and spatial information</title>

Image and Signal Processing for Remote Sensing XI, 2005

Research paper thumbnail of Anomaly detection in complex environments: Evaluation of the inter-and intra-method consistency

2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, 2009

Research paper thumbnail of Validation of physical unmixing model in the radiative domain

2011 3rd Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), 2011

Research paper thumbnail of <title>Salt diapir movements using SAR interferometry in the Lisan Peninsula, Dead Sea Rift</title>

SAR Image Analysis, Modeling, and Techniques IV, 2002

ABSTRACT

Research paper thumbnail of <title>Searching for life in the Dead Sea: microbiological study using imaging spectroscopy</title>

Remote Sensing for Environmental Monitoring, GIS Applications, and Geology, 2002

ABSTRACT

Research paper thumbnail of Change detection in urban scenes by fusion of SAR and hyperspectral data

Research paper thumbnail of Semi-Automatic Hyperspectral Image Classification of Urban Areas Using Logistic Regression

Research paper thumbnail of Spectral Monitoring of Algal Blooms in an Eutrophic Lake Using Sentinel-2

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium

Eutrophication is a process in which elevated organic matter and nutrients raises the primary pro... more Eutrophication is a process in which elevated organic matter and nutrients raises the primary production of a water body. As a result, the productivity of phytoplankton and biomass are very high at all trophic levels. During bloom event, the spatial and temporal distribution of this phenomena is difficult to be observed using conventional water sampling methods. This work advance the state of the art by using Sentinel-2 (S2) images to estimate chlorophyll-a (chl-a) concentration with an empirical model. Specifically, the model uses band 8 (NIR) and band 4 (red) to predict chl-a concentration during an algal bloom event in San Roque lake, Córdoba, Argentina. Nevertheless, novel spectral ratio for algae composition patterns has also been created using bands 8a and 9. The results show that S2 has the potential to monitor bloom events in eutrophic lakes.

Research paper thumbnail of The GEPATAR project: GEotechnical and Patrimonial Archives Toolbox for ARchitectural conservation in Belgium

EGU General Assembly Conference Abstracts, Apr 1, 2018

Research paper thumbnail of Advancing the retrievals of surface emissivity by modelling the spatial distribution of temperature in the thermal hyperspectral scene

Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XXII, 2016

Land Surface Temperature (LST) and Land Surface Emissivity (LSE) are commonly retrieved from ther... more Land Surface Temperature (LST) and Land Surface Emissivity (LSE) are commonly retrieved from thermal hyperspectral imaging. However, their retrieval is not a straightforward procedure because the mathematical problem is ill-posed. This procedure becomes more challenging in an urban area where the spatial distribution of temperature varies substantially in space and time. For assessing the influence of several spatial variances on the deviation of the temperature in the scene, a statistical model is created. The model was tested using several images from various times in the day and was validated using in-situ measurements. The results highlight the importance of the geometry of the scene and its setting relative to the position of the sun during day time. It also shows that when the position of the sun is in zenith, the main contribution to the thermal distribution in the scene is the thermal capacity of the landcover materials. In this paper we propose a new Temperature and Emissivity Separation (TES) method which integrates 3D surface and landcover information from LIDAR and VNIR hyperspectral imaging data in an attempt to improve the TES procedure for a thermal hyperspectral scene. The experimental results prove the high accuracy of the proposed method in comparison to another conventional TES model.

Research paper thumbnail of The independent service validation in GMES RESPOND: the flood validation exercise

International Journal of Digital Earth, 2011

ABSTRACT This article is aimed at providing a detailed description of the Flood Validation Exerci... more ABSTRACT This article is aimed at providing a detailed description of the Flood Validation Exercise organised by the Independent Service Validation Group of the Global Monitoring for Environment and Security (GMES) RESPOND project. The aims of the validation exercise were: (1) providing a practical example of validation procedures in the frame of the GMES Emergency Response services; (2) executing a full-scale validation exercise able to cope with the requirements of an emergency service; and (3) better understanding the performances and limitations of Earth observation services for Flood Damage Mapping. This validation exercise is a first step of the main task to define the whole validation process for GMES services. When this is achieved, there will be knowledge concerning how well services meet the service specifications derived from the user needs. The present exercise has the purpose of gathering this knowledge. The output of this validation exercise can be used to characterise and qualify the performance and timeliness of Crisis and Damage Mapping Services. This paper summarises the methodology for the flood exercise validation and the results of product validation and inter-comparison.

Research paper thumbnail of <title>Quality of topographic data from interferometry SAR DEM for hydrological researches: The case study of the Lesse and the Dendre rivers, Belgium</title>

Remote Sensing for Agriculture, Ecosystems, and Hydrology III, 2002

For hydrology and terrestrial ecosystem studies, topography has a significant influence on the am... more For hydrology and terrestrial ecosystem studies, topography has a significant influence on the amount of intercepted solar radiation, the surface and sub-surface water movements, the type and distribution of vegetation and the microclimate. Processing Digital Elevation Model (DEM) data to extract hydrological features becomes a routine, but the numerous DEMs available stress the importance of their quality assessment. Radar interferometry (InSAR) technique is a promising approach to generate digital elevation models. The goal of this research is to verify to what extend the InSAR DEM can be used as a topographic database for deriving hydrological informations. This study was realised over the Dendre and the Lesse watersheds. Because DEM quality cannot be determined by a single criterion, the quality assessment should be application oriented. In this study, the NGI (National Geographic Institute of Belgium) DEM was chosen as a topographic reference for the quality assessment of the InSAR DEMs. The Root Mean Square (RMS) of the altitude difference between the NGI and the InSAR DEM was used as general quality measurement. The mean slope value has been calculated to characterise the relief of the basin. For both of the basins, watershed borders and hydrographic network were generated with GIS technique. The results obtained were compared between them and with digitised hydrographic network. Hydrographic network derived from InSAR DEM was not found accurate enough in flat wide valley. For the studied areas, the InSAR DEMs are precise enough for large-scale hydrological investigation where information like watershed border or relief is needed. However, InSAR DEMs is not suitable for hydraulic models, because they require extreme accuracy.

Research paper thumbnail of Treaty Monitoring

Remote Sensing from Space, 2009

... of satellite imagery as an essential part of the nuclear safeguards system of the Internation... more ... of satellite imagery as an essential part of the nuclear safeguards system of the International Atomic Energy Agency (IAEA) is a good example of MTM. ... The NPT related activities can essentially be broken down into three phases: 1. Operation 2. Shut-down 3. De-commission Fig. ...

Research paper thumbnail of The comparability of aggregated emissivity and temperature of heterogeneous pixel to conventional tes methods

2013 5th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), 2013

Unmixing in the reflective domain is a well known technique to retrieve materials and their abund... more Unmixing in the reflective domain is a well known technique to retrieve materials and their abundances from hyperspectral imaging scene. However, for the thermal domain (8–14 μm) only few unmixing models were developed due to the complexity of retrieving three unknowns (i.e. materials abundance, temperature and emissivity) from the pixel radiance. Attempt to solve this complexity is using aggregation models. The aggregation models are physics based models which estimate the pixel radiance with the contribution of acquisition parameters and scene description including the temperature and the emissivity of materials. This paper focuses on the comparison of temperature / emissivity estimated using inhouse aggregation model with two conventional Temperature and Emissivity Separation (TES) methods: Maximum Minimum Differences (MMD/TES) and SPectral SMoothness method (SpSm). This comparison is achieved using synthetic mixed pixels of two sensors AHS-160 and SEBASS. The results show that b...

Research paper thumbnail of Urban features classification using 3D hyperspectral data

2013 5th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), 2013

The surface classification of heterogeneous urban areas can be refined using the integration of s... more The surface classification of heterogeneous urban areas can be refined using the integration of spectral and 3D information. However, pixel-classification based fusion requires semi-pixel geo-registration accuracy. In this paper the 3D information is obtained from the hyperspectral data set itself. This study presents an adaptation of optimized MRF based stereo matching for the creation of 3D scenes using hyperspectral data. The obtained 3D information is integrated into a SVM classifier procedure. The results obtained in this study show the potential in the creation of 3D scenes using hyperspectral data and the benefit of combining this data with spectral information for better classification of the urban materials.

Research paper thumbnail of Analysis of the unmixing on thermal hyperspectral imaging

Research paper thumbnail of Airborne hyperspectral potential for coastal biogeochemistry of the Scheldt estuary and plume

Research paper thumbnail of Detection of vehicles in shadow areas using combined hyperspectral and lidar data

2011 IEEE International Geoscience and Remote Sensing Symposium, 2011

ABSTRACT In an effort to overcome the limitations of small target detection in complex urban scen... more ABSTRACT In an effort to overcome the limitations of small target detection in complex urban scene, complementary data sets are combined to provide additional insight about a particular scene. This paper presents a method based on shape/spectral integration (SSI) decision level fusion algorithm to improve the detection of vehicles in semi and deep shadow areas. A four steps process combines high resolution LIDAR and hyperspectral data to classify shadow areas, segment vehicles in LIDAR data, detect spectral anomalies and improves vehicle detection. The SSI decision level fusion algorithm was shown to outperform detection using a single data set and the utility of shape information was shown to be a way to enhance spectral target detection in complex urban scenes.

Research paper thumbnail of Detection of occluded targets using thermal imaging spectroscopy

2010 2nd Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, 2010

Automatic detection of occluded targets from a sequence of images is an interesting area of resea... more Automatic detection of occluded targets from a sequence of images is an interesting area of research for defense related application. In this paper, change detection methods are investigated for the detection of buried improvised explosive devices (IED) using temporal thermal hyperspectral scenes. Specifically, the paper assesses the detection of buried small aluminium plates using the TELOPS Hyper-Cam sensor and by

Research paper thumbnail of Fusion of PolSAR and PolInSAR data for land cover classification

International Journal of Applied Earth Observation and Geoinformation, 2009

Research paper thumbnail of <title>Supervised classification of hyperspectral images using a combination of spectral and spatial information</title>

Image and Signal Processing for Remote Sensing XI, 2005

Research paper thumbnail of Anomaly detection in complex environments: Evaluation of the inter-and intra-method consistency

2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, 2009

Research paper thumbnail of Validation of physical unmixing model in the radiative domain

2011 3rd Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), 2011

Research paper thumbnail of <title>Salt diapir movements using SAR interferometry in the Lisan Peninsula, Dead Sea Rift</title>

SAR Image Analysis, Modeling, and Techniques IV, 2002

ABSTRACT

Research paper thumbnail of <title>Searching for life in the Dead Sea: microbiological study using imaging spectroscopy</title>

Remote Sensing for Environmental Monitoring, GIS Applications, and Geology, 2002

ABSTRACT

Research paper thumbnail of Change detection in urban scenes by fusion of SAR and hyperspectral data

Research paper thumbnail of Semi-Automatic Hyperspectral Image Classification of Urban Areas Using Logistic Regression