Pierre-Louis Frison's research while affiliated with University of Paris-Est and other places

Publications (27)

Conference Paper
C-band radar remote sensing is a suitable tool for monitoring agricultural areas on a large scale, providing access to information on vegetation such as plant biomass, or on the surface water content of the soil. Recent studies suggest that the water state and the physiological functioning of trees influence radar response leading to marked daily p...
Article
Full-text available
Natural disasters like floods are happening worldwide. Due to their negative impact on different social, economic and environmental aspects need to monitor and map these phenomena have increased. In fact, to access the zones affected by the flood, we use open source remote sensing (RS) images acquired by optical and radar sensors. Furthermore, we p...
Article
Full-text available
Natural disasters like floods are happening worldwide. Due to their negative impact on different social, economic and environmental aspects need to monitor and map these phenomena have increased. In fact, to access the zones affected by the flood, we use open source remote sensing (RS) images acquired by optical and radar sensors. Furthermore, we p...
Article
Full-text available
Crop mapping in Loukkos perimeter (Morocco): Radar and optical remote sensing contributions. Dans cet article, nous analysons la possibilité d’amélioration de la classification des cultures dans un périmètre irrigué du nord du Maroc en se basant sur la combinaison des données multi-temporelles de deux satellites (Sentinel-1 et Sentinel-2) avec l’i...
Article
Radar data at C-band has shown great potential for the monitoring of soil and canopy hydric conditions of wheat crops. In this study, the C-band Sentinel-1 time series including the backscattering coefficients σ0 at VV and VH polarization, the polarization ratio (PR) and the interferometric coherence ρ are first analyzed with the support of experim...
Article
1. The recent availability of high spatial and temporal resolution optical and radar satellite imagery has dramatically increased opportunities for mapping land cover at fine scales. Fusion of optical and radar images has been found useful in tropical areas affected by cloud cover because of their complementarity. However, the multitemporal dimensi...
Article
Full-text available
Up-to-date land cover maps are important for biodiversity monitoring as they are central to habitat and ecosystem distribution assessments. Satellite remote sensing is a key technology for generating these maps. Until recently, land cover mapping has been limited to static approaches, which have primarily led to the production of either global maps...
Article
The prediction of grasslands plant diversity using satellite image time series is considered in this article. Fifteen months of freely available Sentinel optical and radar data were used to predict taxonomic and functional diversity at the pixel scale (10 m × 10 m) over a large geographical extent (40,000 km2). 415 field measurements were collected...
Article
Cet article présente quelques illustrations d.applications de données radar polarimétriques (complètes ou partielles) pour le suivi des surfaces terrestres. La première partie est dédiée aux données radar pleinement polarimétriques. Elle est introduite par un rappel théorique présentant leur spécificité. Puis quelques exemples sont présentés, princ...
Article
La période actuelle est caractérisée par une abondance de données radar libres d'accès dont l'utilisation est encouragée et facilitée par les agences spatiales, ces dernières mettant gratuitement à disposition des utilisateurs des logiciels de traitement et d'analyse d'images. Parallèlement, plusieurs sites académiques ou institutionnels proposent...
Article
Full-text available
In this study, the potential of Sentinel-1 data to seasonally monitor temperate forests was investigated by analyzing radar signatures observed from plots in the Fontainebleau Forest of the Ile de France region, France, for the period extending from March 2015 to January 2016. Radar backscattering coefficients, σ0 and the amplitude of temporal inte...
Chapter
Scatterometers are sidelooking radar sensors designed to precisely evaluate the radar backscatter coefficient ?? of the surfaces being observed. However, as we will aim to demonstrate, this high radiometric resolution is obtained at the cost of spatial resolution. Scatterometers are therefore radar sensors complementary to synthetic aperture radars...
Article
Full-text available
In Europe, water levels in wetlands are widely controlled by environmental managers and farmers. However, the influence of these management practices on hydrodynamics and biodiversity remains poorly understood. This study assesses advantages of using radar data from the recently launched Sentinel-1A satellite to monitor hydrological dynamics of the...
Article
The transfer of energy and water, as well as gaseous components, in the soil–plant–atmosphere system plays a crucial role in many processes involved in climate change. The surface energy balance drives both evapotranspiration (closely linked to the CO2 flux) and sensible heat flux. By providing direct information on heat dissipation efficiency, sur...
Article
This study presents a comprehensive comparison of radar signatures acquired over West-Africa at both Ku- and C- bands using nadir-looking altimeters and side-looking scatterometers that covers the major bioclimatic zones, soil and vegetation types encountered in this region. The backscattering coefficients time series measured by both radar instrum...

Citations

... Droughts have a major effect on agriculture, economy, ecology and the natural resources underlying the area. Droughts increase in severity and duration, affecting more citizens over a longer period than any other natural disaster (Tigkas et al. 2012;Benzougagh et al. 2020Benzougagh et al. , 2021. In recent decades, numerous drought indexes have been published in the literature and are commonly used in many parts of the world. ...
... Les principaux résultats de ce travail de recherche ont fait l'objet à des publications dont trois sont déjà publiées (Acharki et al., 2020a(Acharki et al., , 2019(Acharki et al., , 2020b et un autre en cours de publication (Acharki et al., 2020c). ...
... In order to achieve a balance between agricultural production and water availability, a good monitoring of the crop hydric conditions is necessary. Numerous studies have been conducted on the measurement and estimation of the water balance components of the crops in the semi-arid region of Tensift Al Haouz but most of these studies were carried out in the plain (Amazirh et al., 2017;Aouade et al., 2020;Diarra et al., 2017;Er-Raki et al., 2010;Ezzahar et al., 2007a;Ouaadi et al., 2020;Rafi et al., 2019). By contrast, the mountain foothills in semi-arid regions are potential recharge areas for the groundwater table (Blasch and Bryson, 2007;Bouimouass et al., 2020;Liu and Yamanaka, 2012;Martinez et al., 2017). ...
... To relate radar signals to in situ measurements, such as soil moisture and roughness [30] and biophysical vegetation parameters across covered fields, different radar backscattering models have been employed [31,32]. Some of the aforementioned models are based on physical approaches, such as the Karam model based on the physical interactions of electromagnetic waves with vegetation [33,34], and semi-empirical approaches, such as the Michigan microwave canopy scattering model that divides the vegetation canopy into multilayer compositions [31,[35][36][37][38] and the water cloud model (WCM) [18,27,[39][40][41][42][43][44][45][46]. ...
... The simplicity of the WCM makes it widely used in the literature where backscattering is the sum of the contributions of three components, namely, vegetation, soil scattering attenuated with the vegetation effect and soil-vegetation interactions. Bare soil backscattering is calculated through a wide range of models coupled to the WCM including physical approaches, such as the geometric optic model (GOM) [21], integral equation model (IEM) [47], AIEM [28,48], and IEM modified by Baghdadi (IEM-B) [18,49], and semi-empirical approaches, such as the Oh model [50][51][52] or empirical models requiring calibration and validation (particularly exponential [21,53] or linear relationships [43,44], respectively). ...
... It was chosen because it has demonstrated high accuracy compared to other traditional classifiers (i.e. SVM, kNN) (Pal, 2005;Pelletier et al., 2016;Lopes et al., 2020). Likewise, because it has successfully been applied in Morrocan irrigated area (Acharki, 2020;Acharki et al., 2020) and protected area (Acharki et al., 2021). ...
... In the present study, we followed a multi-temporal approach by using the MODIS database; in other words, we used all available images over a one-year period, i.e., 23 images in the case of the Vegetation Index product, and 46 in the case of Land Surface Reflectance and Land Surface Temperature and Emissivity products ( Table 1). The multitemporal approach has been reported to increase mapping accuracy in comparison with a single-date approach [21]. However, to deal with cloud contamination, we created composite images and combined features coming from both satellites (Terra and Aqua). ...
... However, the complexity of the SAR backscatter, the enlarged footprint from oblique observation, and signal noise might limit the discrimination of individual trees (Bae et al., 2019). Still, radar information could be valuable, providing information regarding the understory and soil water content, which could relate to the distribution of species governing the top of the canopy (Fauvel et al., 2020). Spaceborne lidar does not yet offer comparable coverage and resolutions. ...
... Earth observation sensors and their different properties have a high potential for large-scale biodiversity sensing [6], grassland intensity use [4,7,8], grassland management monitoring [9,10], and characterisation of different grassland types [11]. The higher spatial, spectral and temporal resolution of available data has opened up the possibility of coming closer to the precise classification of individual plant species based on their spectral characteristics and ground-observed data [6]. ...
... Other optical satellite constellations that allow the estimation of land surface phenology metrics include Landsat at the decametric scale (Li et al., 2019) and PlanetScope at the 3-m spatial resolution (Cheng et al., 2020). Land surface phenology metrics in temperate mixed forests can be also estimated using the active C-band sensor in Sentinel-1 (Frison et al., 2018). High-resolution satellite data can potentially improve the monitoring of future responses of forests to climate change and, particularly, to heatwave and droughts (Hartmann et al., 2022). ...