Franck Garestier - Academia.edu (original) (raw)

Papers by Franck Garestier

Research paper thumbnail of Polarimetric Interferometry Applied to High Resolution Imagery and Urban Areas

2006 IEEE International Symposium on Geoscience and Remote Sensing, 2006

ABSTRACT

Research paper thumbnail of Polarimetric Repeat-Pass Interferometric Airborne UHF SAR Data Acquisition and Calibration

Research paper thumbnail of Estimation of a forest backscatter profile at P-band using Single Baseline (Pol-)InSAR

Research paper thumbnail of Analysis of Forest Parameters and Agricultural Field Structure from high resolution PolInSAR X-band data

Forest parameters extraction (height and mean extinction coefficient) has been evaluated successf... more Forest parameters extraction (height and mean extinction coefficient) has been evaluated successfully at L band using RVoG model. The first part of this work relates the investigation of a pine forest on a high resolution X band SAR data set. Using ground truth measurements of forest height, the mean extinction is estimated with its precision. In the second part, observations on orientation effect occurring at X band on some agricultural fields (wheat, hay and high grass) are related.

Research paper thumbnail of Using Pol-InSAR at X-band: preliminary observations

IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003

Research paper thumbnail of Polar and PolInSAR analysis of pine forest at L and P band on high resolution data

Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005

A well known Pine forest has been investigated at L and P band on high resolution PolInSAR datase... more A well known Pine forest has been investigated at L and P band on high resolution PolInSAR datasets. A previous polarimetric analysis has evaluated L and P band potential for the biomass estimation. It shows a good correlation with the polarimetric parameters at P band. The PolInSAR investigation at this frequency allows an identification of elementary scatterers and of an

Research paper thumbnail of Resolution effects on polarimetric high resolution X band data

Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005

Resolution impact on the information contained in a polarimetric dataset is investigated with a h... more Resolution impact on the information contained in a polarimetric dataset is investigated with a high resolution X band polarimetric data set. Resolution images are degraded by spectral filtering to simulate low resolution data and the polarimetric parameters (Alpha angle, Entropy, Anisotropy and Span) are estimated over these images for many resolution values. Scattering mechanism modification due to spectral filtering is observed on natural surfaces where a pure surface scattering contribution is removed and over urban areas, where different scattering mechanisms are affected.

Research paper thumbnail of Modeling of als intensity behavior as a function of incidence angle for coastal zone surface study

2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

Backscatter intensity of the LiDAR, recorded simultaneously with the discrete topography measurem... more Backscatter intensity of the LiDAR, recorded simultaneously with the discrete topography measurements, was recently investigated, providing complementary information to study coastal environments. The aim of this study was (i) to analyze the intensity-incidence angle behavior for coastal environments (sea and moist sand surfaces) and other surfaces (fields and urban area) with different reflectance models and (ii) to choose the best modeling for all these surfaces. We compared three reflection models. Firstly, diffuse reflection is introduced by Lambert's cosine law. The illuminated surfaces are composed of numerous small mirror-like facets inducing a dominant specular diffusion. This scattering of micro-facets is defined by the Beckmann distribution. The last model is a combination of diffuse and specular reflection. In this paper, we found that Beckmann distribution well simulates the intensity-incidence behavior for specular and diffuse mechanisms with the advantage to have only one parameter to characterize the studied surfaces.

Research paper thumbnail of Entropy-Alpha Analysis using Automatic Pre-Segmentation procedure

Research paper thumbnail of THE SPECIFICITY OF P BAND POLINSAR DATA OVER VEGETATION

ABSTRACT/RESUME A polarimetric and PolInSAR analysis has been con- ducted on the Nezer forest (So... more ABSTRACT/RESUME A polarimetric and PolInSAR analysis has been con- ducted on the Nezer forest (Southern France) at L and P band on high resolution SAR data acquired with the ONERA RAMSES system in January 2004. The dataset was investigated for its potential for re- trieval of forest parameters from SAR data using three different techniques: •,Radiometric,inversion from,the cross-polarized term, •,PolInSAR

Research paper thumbnail of Forest height estimation using P-band Pol-InSAR data

A P-band Pol-InSAR dataset acquired over a mar- itime pine forest is evaluated for forest height ... more A P-band Pol-InSAR dataset acquired over a mar- itime pine forest is evaluated for forest height estimation . First, a time-frequency inversion methodology is presented. Good results have been obtained (2 m RMS error over 27 stands). However, since the method is adapted to airborne SAR data, we further investigate methods that could be used to invert spaceborne SAR data.

Research paper thumbnail of The ONERA RAMSES SAR: Latest Significant Results and Future Developments

2006 IEEE Conference on Radar, 2006

The last SAR campaigns of the French ONERA RAMSES system have been dedicated to various applicati... more The last SAR campaigns of the French ONERA RAMSES system have been dedicated to various applications, military or civilian, including Very-high resolution, FOPEN (Foliage penetration) in cooperation with the FOI, MTI, Bistatic SAR and vegetation characterization. These different projects gave us the opportunity to improve our sar processing procedure (Very High Resolution) and to develop new algorithms (Bistatic scenario). In parallel, the ONERA team has developed and applied many techniques (polarimetric analysis, PolInSAR, Wavelet analysis) which proved to be efficient in these different thematic context. The current aircraft platform, a Transall C160 will be decommissioned at the end of 2008. In order to maintain our activities, we are developing a new system family compatible with smaller aircrafts. The challenge is two fold : migrating the existing radars in a airplane four times smaller and maintaining our innovation capabilities with the development of new radar concepts. These paper presents the most recent results on SAR techniques and describes the status of the development of the RAMSES successors : the first, SETHI, dedicated to military applications and earth observation, the second, BUSARD more focused on UAV applications. 518 0-7803-9497-6/06/$20.00

Research paper thumbnail of Anisotropic surfaces detection using intensity maps acquired by an airborne LiDAR emitting in near-IR over coastal environments

2011 IEEE International Geoscience and Remote Sensing Symposium, 2011

Backscatter intensity maps associated with DEMs acquired by an airborne LiDAR are analyzed to est... more Backscatter intensity maps associated with DEMs acquired by an airborne LiDAR are analyzed to estimate surface physical parameters in coastal environments. Since the texture of the intensity maps reflects geomorphological features, different estimators have been developed and evaluated for detection of spatial anisotropy. LiDAR data are analyzed to form an unbiased anisotropy map, fully independent of the intensity level.

Research paper thumbnail of Vegetation modelling for height inversion using InSAR/Pol-InSAR data

2007 IEEE International Geoscience and Remote Sensing Symposium, 2007

ABSTRACT

Research paper thumbnail of Forest Biomass Estimation from P-Band High Incidence Angle Data

The ONERA airborne experimental SAR system RAMSES has recently been upgraded with a mode operatin... more The ONERA airborne experimental SAR system RAMSES has recently been upgraded with a mode operating P and L-band polarimetric SARs simultaneously. During the validation campaign in January 2004, we acquired data over the Nezer Forest in Aquitaine with several geometries. We flew the system over the well-studied forest site with two main effective incidence angles, 45° and 25°. The data was then processed and calibrated using natural targets, several trihedral reflectors and one dihedral. The experimental site chosen for the radar campaign is well-known as it has been at the centre of numerous radar studies : for example, it was one of the five European test-sites selected during the Maestro and Mac Europe radar campaigns (1989 and 1990). This site has been monitored since 1987 The tree stands are geographically well defined and very uniform. It is mostly a planted forest with monospecific maritime pine stands characterized by the age. The biomass ranges from 0 to maximum 150 t/ha. The results presented in this paper describe the behavior of the forest backscatter at HH, VV and HV polarization for a wide range of biomass, forest height and two incidence angles. Previous works have shown that good inversion result can be empirically obtained at P-band for the 40-50° incidence angle range based on the HV return. However, assessing the potential of such a technique for steeper incidence angle is quite important in the perspective of future space-borne system where system performance requires the full polarimetry mode to operate at a steeper incidence angle. We study how several biophysical parameters like forest age and forest biomass influence the different polarimetric backscatter parameters for the two incidence angles .

Research paper thumbnail of Pine forest investigation using high resolution P-band Pol-InSAR data

Remote Sensing of Environment, 2011

In this paper, a high-resolution P-band Pol-InSAR 4 data set acquired by the airborne RAMSES syst... more In this paper, a high-resolution P-band Pol-InSAR 4 data set acquired by the airborne RAMSES system over pine forest 5 stands of different height is investigated. A significant penetration 6 depth in all the polarimetric channels and a wide range of polari-7 metric-phase-center heights are observed, attesting of an interac-8 tion of the radar waves with different forest structural elements. 9 The main objective of this paper concerns forest-height inversion 10 at P-band. First, forest-modeling assumptions are evaluated us-11 ing ap r i o r iinformation, such as ground-level and forest-height 12 measurements. The full extend of the forest height is shown to 13 be responsible of the volume decorrelation, and a significant ori-14 entation effect is clearly identified over the highest stands. As a 15 consequence, the Oriented Volume over Ground model (OVoG) 16 is determined to be the most appropriated model for the 17 forest-height inversion. At P-band, the ground contribution is Q1 18 present in all the polarimetric channels due to the important 19 penetration at this frequency. To overcome this difficulty, a 20 time-frequency optimization method based on sublook decom-21 position is developed to separate the pure ground and canopy 22

Research paper thumbnail of Forest Biophysical Parameter Estimation Using L- and P-Band Polarimetric SAR Data

IEEE Transactions on Geoscience and Remote Sensing, 2000

L-and P-band airborne polarimetric synthetic aperture radar (SAR) data acquired by the RAMSES sys... more L-and P-band airborne polarimetric synthetic aperture radar (SAR) data acquired by the RAMSES system over different height maritime pine (Pinus Pinaster Ait.) stands of the Nezer forest (Landes, France) have been evaluated for forest biophysical parameter estimation. A pseudolinear correlation has been brought to evidence at P-band between polarimetric anisotropy and mean tree height, which is also linked to other biophysical parameters in the Nezer forest, meaning that SAR polarimetry constitutes a promising tool for forest parameter retrieval at low frequency. The spatial conditions have been evaluated through the quantification of the impact of signal-to-noise ratio diminution and resolution degradation on the forest height inversion. It has been shown that the inversion accuracy remains acceptable for N Eσ 0 , representing the noise level of the SAR image, which is lower than −15 dB, and for spatial resolution increasing up to 15 m.

Research paper thumbnail of Forest Height Inversion Using High-Resolution P-Band Pol-InSAR Data

IEEE Transactions on Geoscience and Remote Sensing, 2000

In this paper, a high-resolution P-band Pol-InSAR data set acquired by the airborne RAMSES system... more In this paper, a high-resolution P-band Pol-InSAR data set acquired by the airborne RAMSES system over pine forest stands of different height is investigated. A significant penetration depth in all the polarimetric channels and a wide range of polarimetric phase center heights are observed, attesting of an interaction of the radar waves with different forest structural elements. The main objective

Research paper thumbnail of Forest Modeling For Height Inversion Using Single-Baseline InSAR/Pol-InSAR Data

IEEE Transactions on Geoscience and Remote Sensing, 2000

ABSTRACT

Research paper thumbnail of The Compact Polarimetry Alternative for Spaceborne SAR at Low Frequency

IEEE Transactions on Geoscience and Remote Sensing, 2000

In spaceborne synthetic aperture radar (SAR), a single-polarization on-transmit offers twice the ... more In spaceborne synthetic aperture radar (SAR), a single-polarization on-transmit offers twice the swath width compared to full polarization. This is linked to SAR system design issues, and, without getting into the technical details deserving by themselves a full paper, we can just mention the swath characteristics of ALOS PALSAR (the Advanced Land Observing Satellite, Phased Array L-Band Synthetic Aperture Radar),

Research paper thumbnail of Polarimetric Interferometry Applied to High Resolution Imagery and Urban Areas

2006 IEEE International Symposium on Geoscience and Remote Sensing, 2006

ABSTRACT

Research paper thumbnail of Polarimetric Repeat-Pass Interferometric Airborne UHF SAR Data Acquisition and Calibration

Research paper thumbnail of Estimation of a forest backscatter profile at P-band using Single Baseline (Pol-)InSAR

Research paper thumbnail of Analysis of Forest Parameters and Agricultural Field Structure from high resolution PolInSAR X-band data

Forest parameters extraction (height and mean extinction coefficient) has been evaluated successf... more Forest parameters extraction (height and mean extinction coefficient) has been evaluated successfully at L band using RVoG model. The first part of this work relates the investigation of a pine forest on a high resolution X band SAR data set. Using ground truth measurements of forest height, the mean extinction is estimated with its precision. In the second part, observations on orientation effect occurring at X band on some agricultural fields (wheat, hay and high grass) are related.

Research paper thumbnail of Using Pol-InSAR at X-band: preliminary observations

IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003

Research paper thumbnail of Polar and PolInSAR analysis of pine forest at L and P band on high resolution data

Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005

A well known Pine forest has been investigated at L and P band on high resolution PolInSAR datase... more A well known Pine forest has been investigated at L and P band on high resolution PolInSAR datasets. A previous polarimetric analysis has evaluated L and P band potential for the biomass estimation. It shows a good correlation with the polarimetric parameters at P band. The PolInSAR investigation at this frequency allows an identification of elementary scatterers and of an

Research paper thumbnail of Resolution effects on polarimetric high resolution X band data

Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005

Resolution impact on the information contained in a polarimetric dataset is investigated with a h... more Resolution impact on the information contained in a polarimetric dataset is investigated with a high resolution X band polarimetric data set. Resolution images are degraded by spectral filtering to simulate low resolution data and the polarimetric parameters (Alpha angle, Entropy, Anisotropy and Span) are estimated over these images for many resolution values. Scattering mechanism modification due to spectral filtering is observed on natural surfaces where a pure surface scattering contribution is removed and over urban areas, where different scattering mechanisms are affected.

Research paper thumbnail of Modeling of als intensity behavior as a function of incidence angle for coastal zone surface study

2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

Backscatter intensity of the LiDAR, recorded simultaneously with the discrete topography measurem... more Backscatter intensity of the LiDAR, recorded simultaneously with the discrete topography measurements, was recently investigated, providing complementary information to study coastal environments. The aim of this study was (i) to analyze the intensity-incidence angle behavior for coastal environments (sea and moist sand surfaces) and other surfaces (fields and urban area) with different reflectance models and (ii) to choose the best modeling for all these surfaces. We compared three reflection models. Firstly, diffuse reflection is introduced by Lambert's cosine law. The illuminated surfaces are composed of numerous small mirror-like facets inducing a dominant specular diffusion. This scattering of micro-facets is defined by the Beckmann distribution. The last model is a combination of diffuse and specular reflection. In this paper, we found that Beckmann distribution well simulates the intensity-incidence behavior for specular and diffuse mechanisms with the advantage to have only one parameter to characterize the studied surfaces.

Research paper thumbnail of Entropy-Alpha Analysis using Automatic Pre-Segmentation procedure

Research paper thumbnail of THE SPECIFICITY OF P BAND POLINSAR DATA OVER VEGETATION

ABSTRACT/RESUME A polarimetric and PolInSAR analysis has been con- ducted on the Nezer forest (So... more ABSTRACT/RESUME A polarimetric and PolInSAR analysis has been con- ducted on the Nezer forest (Southern France) at L and P band on high resolution SAR data acquired with the ONERA RAMSES system in January 2004. The dataset was investigated for its potential for re- trieval of forest parameters from SAR data using three different techniques: •,Radiometric,inversion from,the cross-polarized term, •,PolInSAR

Research paper thumbnail of Forest height estimation using P-band Pol-InSAR data

A P-band Pol-InSAR dataset acquired over a mar- itime pine forest is evaluated for forest height ... more A P-band Pol-InSAR dataset acquired over a mar- itime pine forest is evaluated for forest height estimation . First, a time-frequency inversion methodology is presented. Good results have been obtained (2 m RMS error over 27 stands). However, since the method is adapted to airborne SAR data, we further investigate methods that could be used to invert spaceborne SAR data.

Research paper thumbnail of The ONERA RAMSES SAR: Latest Significant Results and Future Developments

2006 IEEE Conference on Radar, 2006

The last SAR campaigns of the French ONERA RAMSES system have been dedicated to various applicati... more The last SAR campaigns of the French ONERA RAMSES system have been dedicated to various applications, military or civilian, including Very-high resolution, FOPEN (Foliage penetration) in cooperation with the FOI, MTI, Bistatic SAR and vegetation characterization. These different projects gave us the opportunity to improve our sar processing procedure (Very High Resolution) and to develop new algorithms (Bistatic scenario). In parallel, the ONERA team has developed and applied many techniques (polarimetric analysis, PolInSAR, Wavelet analysis) which proved to be efficient in these different thematic context. The current aircraft platform, a Transall C160 will be decommissioned at the end of 2008. In order to maintain our activities, we are developing a new system family compatible with smaller aircrafts. The challenge is two fold : migrating the existing radars in a airplane four times smaller and maintaining our innovation capabilities with the development of new radar concepts. These paper presents the most recent results on SAR techniques and describes the status of the development of the RAMSES successors : the first, SETHI, dedicated to military applications and earth observation, the second, BUSARD more focused on UAV applications. 518 0-7803-9497-6/06/$20.00

Research paper thumbnail of Anisotropic surfaces detection using intensity maps acquired by an airborne LiDAR emitting in near-IR over coastal environments

2011 IEEE International Geoscience and Remote Sensing Symposium, 2011

Backscatter intensity maps associated with DEMs acquired by an airborne LiDAR are analyzed to est... more Backscatter intensity maps associated with DEMs acquired by an airborne LiDAR are analyzed to estimate surface physical parameters in coastal environments. Since the texture of the intensity maps reflects geomorphological features, different estimators have been developed and evaluated for detection of spatial anisotropy. LiDAR data are analyzed to form an unbiased anisotropy map, fully independent of the intensity level.

Research paper thumbnail of Vegetation modelling for height inversion using InSAR/Pol-InSAR data

2007 IEEE International Geoscience and Remote Sensing Symposium, 2007

ABSTRACT

Research paper thumbnail of Forest Biomass Estimation from P-Band High Incidence Angle Data

The ONERA airborne experimental SAR system RAMSES has recently been upgraded with a mode operatin... more The ONERA airborne experimental SAR system RAMSES has recently been upgraded with a mode operating P and L-band polarimetric SARs simultaneously. During the validation campaign in January 2004, we acquired data over the Nezer Forest in Aquitaine with several geometries. We flew the system over the well-studied forest site with two main effective incidence angles, 45° and 25°. The data was then processed and calibrated using natural targets, several trihedral reflectors and one dihedral. The experimental site chosen for the radar campaign is well-known as it has been at the centre of numerous radar studies : for example, it was one of the five European test-sites selected during the Maestro and Mac Europe radar campaigns (1989 and 1990). This site has been monitored since 1987 The tree stands are geographically well defined and very uniform. It is mostly a planted forest with monospecific maritime pine stands characterized by the age. The biomass ranges from 0 to maximum 150 t/ha. The results presented in this paper describe the behavior of the forest backscatter at HH, VV and HV polarization for a wide range of biomass, forest height and two incidence angles. Previous works have shown that good inversion result can be empirically obtained at P-band for the 40-50° incidence angle range based on the HV return. However, assessing the potential of such a technique for steeper incidence angle is quite important in the perspective of future space-borne system where system performance requires the full polarimetry mode to operate at a steeper incidence angle. We study how several biophysical parameters like forest age and forest biomass influence the different polarimetric backscatter parameters for the two incidence angles .

Research paper thumbnail of Pine forest investigation using high resolution P-band Pol-InSAR data

Remote Sensing of Environment, 2011

In this paper, a high-resolution P-band Pol-InSAR 4 data set acquired by the airborne RAMSES syst... more In this paper, a high-resolution P-band Pol-InSAR 4 data set acquired by the airborne RAMSES system over pine forest 5 stands of different height is investigated. A significant penetration 6 depth in all the polarimetric channels and a wide range of polari-7 metric-phase-center heights are observed, attesting of an interac-8 tion of the radar waves with different forest structural elements. 9 The main objective of this paper concerns forest-height inversion 10 at P-band. First, forest-modeling assumptions are evaluated us-11 ing ap r i o r iinformation, such as ground-level and forest-height 12 measurements. The full extend of the forest height is shown to 13 be responsible of the volume decorrelation, and a significant ori-14 entation effect is clearly identified over the highest stands. As a 15 consequence, the Oriented Volume over Ground model (OVoG) 16 is determined to be the most appropriated model for the 17 forest-height inversion. At P-band, the ground contribution is Q1 18 present in all the polarimetric channels due to the important 19 penetration at this frequency. To overcome this difficulty, a 20 time-frequency optimization method based on sublook decom-21 position is developed to separate the pure ground and canopy 22

Research paper thumbnail of Forest Biophysical Parameter Estimation Using L- and P-Band Polarimetric SAR Data

IEEE Transactions on Geoscience and Remote Sensing, 2000

L-and P-band airborne polarimetric synthetic aperture radar (SAR) data acquired by the RAMSES sys... more L-and P-band airborne polarimetric synthetic aperture radar (SAR) data acquired by the RAMSES system over different height maritime pine (Pinus Pinaster Ait.) stands of the Nezer forest (Landes, France) have been evaluated for forest biophysical parameter estimation. A pseudolinear correlation has been brought to evidence at P-band between polarimetric anisotropy and mean tree height, which is also linked to other biophysical parameters in the Nezer forest, meaning that SAR polarimetry constitutes a promising tool for forest parameter retrieval at low frequency. The spatial conditions have been evaluated through the quantification of the impact of signal-to-noise ratio diminution and resolution degradation on the forest height inversion. It has been shown that the inversion accuracy remains acceptable for N Eσ 0 , representing the noise level of the SAR image, which is lower than −15 dB, and for spatial resolution increasing up to 15 m.

Research paper thumbnail of Forest Height Inversion Using High-Resolution P-Band Pol-InSAR Data

IEEE Transactions on Geoscience and Remote Sensing, 2000

In this paper, a high-resolution P-band Pol-InSAR data set acquired by the airborne RAMSES system... more In this paper, a high-resolution P-band Pol-InSAR data set acquired by the airborne RAMSES system over pine forest stands of different height is investigated. A significant penetration depth in all the polarimetric channels and a wide range of polarimetric phase center heights are observed, attesting of an interaction of the radar waves with different forest structural elements. The main objective

Research paper thumbnail of Forest Modeling For Height Inversion Using Single-Baseline InSAR/Pol-InSAR Data

IEEE Transactions on Geoscience and Remote Sensing, 2000

ABSTRACT

Research paper thumbnail of The Compact Polarimetry Alternative for Spaceborne SAR at Low Frequency

IEEE Transactions on Geoscience and Remote Sensing, 2000

In spaceborne synthetic aperture radar (SAR), a single-polarization on-transmit offers twice the ... more In spaceborne synthetic aperture radar (SAR), a single-polarization on-transmit offers twice the swath width compared to full polarization. This is linked to SAR system design issues, and, without getting into the technical details deserving by themselves a full paper, we can just mention the swath characteristics of ALOS PALSAR (the Advanced Land Observing Satellite, Phased Array L-Band Synthetic Aperture Radar),