47 research outputs found
Synergy between optical and microwave remote sensing to derive soil and vegetation parameters from MAC Europe 1991 Experiment
The ability of remote sensing for monitoring vegetation density and soil moisture for agricultural applications is extensively studied. In optical bands, vegetation indices (NDVI, WDVI) in visible and near infrared reflectances are related to biophysical quantities as the leaf area index, the biomass. In active microwave bands, the quantitative assessment of crop parameters and soil moisture over agricultural areas by radar multiconfiguration algorithms remains prospective. Furthermore the main results are mostly validated on small test sites, but have still to be demonstrated in an operational way at a regional scale. In this study, a large data set of radar backscattering has been achieved at a regional scale on a French pilot watershed, the Orgeval, along two growing seasons in 1988 and 1989 (mainly wheat and corn). The radar backscattering was provided by the airborne scatterometer ERASME, designed at CRPE, (C and X bands and HH and VV polarizations). Empirical relationships to estimate water crop and soil moisture over wheat in CHH band under actual field conditions and at a watershed scale are investigated. Therefore, the algorithms developed in CHH band are applied for mapping the surface conditions over wheat fields using the AIRSAR and TMS images collected during the MAC EUROPE 1991 experiment. The synergy between optical and microwave bands is analyzed
Collateral damage? Small-scale fisheries in the global fight against IUU fishing
© 2020 The Authors. Fish and Fisheries published by John Wiley & Sons Ltd Concern over illegal, unreported and unregulated (IUU) fishing has led to a number of policy, trade and surveillance measures. While much attention has been given to the impact of IUU regulation on industrial fleets, recognition of the distinct impacts on small-scale fisheries is conspicuously lacking from the policy and research debate. In this paper, we outline three ways in which the application of IUU discourse and regulation undermines small-scale fisheries. First, the mainstream construction of âillegal,â âunreportedâ and âunregulatedâ fishing, and also the categorical use of âIUUâ in an all-inclusive sense, disregards the diversity, legitimacy and sustainability of small-scale fisheries practices and their governing systems. Second, we explore how the recent trade-related measures to counter IUU fishing mask and reinforce existing inequalities between different sectors and countries, creating an unfair burden on small-scale fisheries and countries who depend on them. Third, as IUU fishing is increasingly approached as âorganized crime,â there is a risk of inappropriately targeting small-scale fisheries, at times violently. Reflecting on these three trends, we propose three strategies by which a more sensitive and ultimately more equitable incorporation of small-scale fisheries can be supported in the global fight against IUU fishing
Estimation de l'évapotranspiration des couverts végétaux par inversion de modÚles de télédétection
National audienc
Investigating the capability of C-band radar to monitor wheat characteristics
International audienc
An overview of the workshop on thermal remote sensing held at La Londe les Maures, France, September 20-24, 1993
This article reviews the major topics discussed at the Thermal Remote Sensing Workshop held at La Londe les Maures, France in 1993 and concludes with a list of new items and concepts suggested during the meeting. / Cet article résume les principaux thÚmes abordés lors du séminaire sur la télédétection dans l'infrarouge thermique, organisé à la Londe Les Maures, France, en 1993, et conclut par des recommandations sur les concepts et les nouvelles approches proposées durant le séminaire