Electromagnetic propagation in urban configuration with asymptotic innovative methods – PECUMIA

Several methods exist to model electromagnetic propagation. These are typically classified into two categories: rigorous methods and asymptotic methods.
Rigorous methods require significant space memory and computational time. They are limited to scenes of restricted size and therefore poorly suited to urban and semi-urban areas.
Asymptotic methods provide an alternative to the use of rigorous methods.
We chose to focus on the asymptotic methods of the 3D Parabolic Wave Equation and the Gaussian Beams Launching.

After a state of the art focused on the considered electromagnetic methods and in urban or semi-urban configurations, we plan to synchronize the development phases (i.e. implementation, validation and comparison) of both methods. The test cases for comparison and validation will be common and will be carried out simultaneously by both methods.
Then, both methods will be applied to model the electromagnetic propagation on «configurations of interest«.
After having made a comparison between the methods, we will propose a strategy of hybridization of both methods that would lead to an «optimal« model leveraging the strengths of each.

At T0+6 months, the project has been mainly focused on the completion of the task 1 «state of the art and definition of the configurations of interest.« Thus, the state of the art of electromagnetic modeling in urban and semi-urban settings has been carried out, and configurations of interest have been defined.

The state of the art was focused on one hand on the methods of the Parabolic Wave Equation and the Gaussian Beam Launching, and the other hand on urban and semi-urban configurations. It helped to highlight the current trends in the development of these methods and their applications to urban and semi-urban areas.

The configurations of interest have also been defined. They aim to prove that the methods of 3DPWE and GBL have the ability to account for the phenomena of radio propagation in dual applications and for urban or semi-urban areas. Thus the tools associated with these methods could help firstly to the analysis of electromagnetic scenes, and secondly produce enough results for optimizing a material installation (eg base station or radar).
The interest is operational and is on the difference between foreseen performance and theoretical performance respect to the scene where the equipment operates. It will estimate the attenuation of a base station connection with a mobile user equipment in the field of the phone or broadband access, or the loss of target detection in the areas of civilian radar, military or security sites.
To do so, we must quantify the shadowing effect and multiple reflections. The configurations of interest are based on the following elements: a closed vertical obstacle at the emission or the reception, an effect of side reflection on a building or a relief effect.

The first possible prospect may be the business development of partners to the identified applications. The project may also be followed by the implementation of the proposed strategy of hybridization.
In addition to urban and semi-urban areas, indoor or through a wall configurations may also be relevant and therefore analyzed. Electromagnetic propagation modeling in these configurations could be resolved by hybridization of both methods.

At this stage of the project, no publication has been prepared and no patent has been filed.

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.