The "electromagnetic propagation inurban configuration with asymptotic innovative methods" (PECUMIA) study mainly aims at allowing the simulation of ElectroMagnetic (EM) propagation in urban or semi-urban configuration, by the 3D Parabolic Equation (3DPE) and the Gaussian Beam Launching (GBL) methods. Indeed, due to the growing urban development, these configurations are and will remain of interest to the scientific community and all players involved in this field. Besides, the methods proposed - in-between "rigourous" methods and ray methods - have proved their value and efficacy in other contexts. The work proposed to reach this aim are organised around the following three lines; - solving problems raised by the simulation of the EM propagation in urban ou semi-urban configuration by 3DPE and GBL methods, and comparing these methods; - supplying proof-of-concept by performing simulations in "configurations of interest"; - proposing a hybridisation strategy. The first stage of the project will consist in developing new formulations and novel algorithms and in programming and validating them by comparing them with reference results. Common test-cases will be defined to allow a comparison between both methods. We will then be able to derive a comparative balance of the methods proposed, in relation to the specific issues raised by propagation in urban or semi-urban configuration. The methods thus validated will be used in the second phase of the project in order to intend to prove that EM propagation in urban or semi-urban configuration can be efficiently be modelled with the innovative methods developed within the project (proof-of-concept). This is the major result expected for this ASTRD project. The third and last stage of the project will rely on the results of the previous stages (comparative balance, proof-of-concept) in order to analyse the interest and feasibility of hybridizing both methods (3DPE and GBL methods), and to propose a relevant strategy that would allow to make the most of both methods and to go beyond their respective limits. As far as we know, such a project proposing to adapt 3DPE and GBL methods for the simulation of EM propagation in urban or semi-urban configuration has never been achieved. The results of this project will be valorised, on the one hand through scientific papers and presentations to specialised conferences or seminars; and on the other hand, through the exploitation of its various spin-offs (scientific, economic...) related to the dual applications identified.

Availibility of climatological databases for surface cover spectral optical properties is a challenge in many civilian themes, such as global warming, meteorological forecasting, ecophysiological processes, land surface hydrology or natural disaster assessment, and in military themes, such as trafficability, mission preparation or strategic survey. Some surface cover reflectance databases built from satellite measurements over several years, with a global coverage, are available. They are climatologically representative but the spectral band extends only from visible to 3 µm at the most. Within the framework of the MIRA PEA, a new global surface cover optical properties database was built from one year of MODIS data. This database has 9 spectral bands between 0.6 and 12.3 µm, a 8-days temporal sampling and a 500-m (1-km) spatial resolution for reflectance (emissivity). Because of the broken spectral coverage, the lack of climatological representativeness and the huge amount of data, the database is hard to process. However, it is the first step to create a global surface cover optical properties database, extending from visible to infrared (14 µm) with a climatological representativeness. The CLIPO project aim is to develop methodologies for the creation of a global surface cover optical properties database which is representative of spatial, temporal and spectral variabilities and with resolutions in agreement with civilian and military needs. These methodologies will be implemented on a globe part in order to demonstrate the project feasibility. The implementation of the final product in radiative transfer codes, like the MATISSE code developed at ONERA, leads to significant work considering the database sizing.