Onera - A partner speaks out - Jean Latger - OKTAL SE - Predicting complex electromagnetic interactions

A partner speaks out

Jean Latger / OKTAL SE:
"Predicting complex electromagnetic interactions"

The Fermat project, run by Onera, Oktal-SE and the Paul Sabatier University in Toulouse, has just been awarded the "Science and Defense" prize by the Ministry of Defense. Feedback from an exemplary collaboration.

Jean Latger - in the middle of the photo - receives the Science and Defense prize 2005. He is surrounded by his Oktal SE colleagues and his partners from Onera and the Paul Sabatier University.

The interview

What is the Fermat project?

Jean Latger: Fermat is a project combining electromagnetism and computing. It has created a software package for modeling electromagnetic waves and predicting their interaction with complex scenes. It is adapted to high frequencies, in particular radar, and terrains of several hundred kilometers, which is really an innovation. But Fermat is also and above all a product marketed by Oktal SE under the name of SE-RAY-EM, which has chalked up a great commercial success! The German and Swedish armies use it; South Korea, Singapore, China, Japan, Taïwan and India are interested. Paradoxically, the French Armaments Procurement Agency (DGA), which set up the "Science and Defense" prize awarded to the Fermat project, does not use it yet. And, of course, Onera uses it regularly. Furthermore, Onera and Oktal-SE have instituted a quite novel method of cooperation: Oktal-SE is responsible for the final product, which it publishes, updates and sells to the customer. Onera receives royalties from the sales but it is first and foremost interested in the right to use the software without charge. This means that Onera can sell its own studies done with our joint product.

How did the collaboration proceed?

JL: Onera contributed its skills in electromagnetism, in particular the asymptotic methods adapted to high radar frequencies, and its expertise in the applications. The Paul Sabatier University played a role in the theoretical developments and jointly supported the students who participated in the project. We, for our part, took care of the computing aspect of Fermat, due to our skills with two tools. Firstly , the technique of "ray tracing", well known in infographics, video games and digital cinema fields, used to represent a complex scene taking into account reflections, the shadows cast, etc. Secondly, we contributed our skills as "terrain modelers:" this is the tool used to create three dimensional scenes ("virtual models") from two dimensional geographic data.

What are this software package's applications?

JL: There are lots of them. For example, calculating the "Radar Cross-Section" (RCS), which characterizes an object's radar signature as a function of the direction of observation, or simulating the electromagnetic environment of sites such as airports, in which many items of electromagnetic equipment interact and can interfere with each other. By computing the electromagnetic interactions, we can predict and limit this interference. Other applications concern the synthesis of radar images, for studying the advantages of a radar imager in a complex system, for example. We are also interested in studying the coupling between an antenna and a structure, in order to optimize its positioning. In all these cases, the Fermat software cannot be used alone. It's a link in a complex chain. It must be associated with upstream data and physical models and downstream technological modeling supplied by the customer or Onera.

Interview:
Cécile Michaut, scientific reporter

The photo album

Paysage MNT
Numerical Model of Terrain [NMT] with the different items enriched with physical properties

SAR image calculated from the preceding NMT, using Fermat [ray tracing + the electromagnetism equations]

Numerical model of terrain with vegetation and infrastructures

Airport infrastructure model (Blagnac Airport)

Military vehicle model, potential target, with its physical diffraction of electromagnetic waves properties

Computation of the field close to mobile telephone antennae

Oktal, Oktal SE:
a Toulouse story

In 1989, when Thalès decided to return to Cergy Pontoise after some years spent in Toulouse, eight engineers chose to remain in the pink city. They founded a computing services company named Oktal as a reference to the eight founders. It specializes in image synthesis and now employs 120 people making training simulators for the automotive, railway, etc. industries, in particular. In 2001, Jean Latger, one of the eight founders, created Oktal-SE, aimed at the defense and security markets, which he still directs. "Our skills are in simulation studies and publishing software on the synthetic environment," indicated the CEO. "Our aim is not to grow at any price, but to develop this technological niche, where we are one of the best in the world." The "Science and Defense" prize, which each year rewards a remarkable scientific and technological achievement of interest to National Defense, will give it added visibility and scientific recognition. "It's rare that an SME receives it", noted Jean Latger with pride.

www.oktal-se.fr

Onera:
a link between University and small and medium-size companies

Far from their ivory tower, Onera's researchers work both with universities on fundamental aspects and industrialists to develop products. The Fermat project is the perfect example of one such collaboration. "We wanted to obtain full value from the results of our research," said André Bergès, one of the three Electromagnetism and Radar Department (DEMR) researchers involved in the project. "As well as contributing our skills in electromagnetism, we created the link between University research, the applications and the transfer to the Oktal-SE SME". Along with the three researchers in post at Onera, André Bergès, Henri-José Mametsa and Vincent Gobin, the project mobilized three doctoral students. The geographical proximity of the three entities proved crucial. "Such a project is unthinkable with a distant partner," stressed the partners, all from Toulouse. Furthermore, the adventure is not over. There are still plenty of applications of the Fermat software waiting to be developed.

Innovative physics

Fermat is an acronym for “Functionalities for electromagnetism and radar by asymptotic methods.” The usual computing methods, based on the basic electromagnetism equations, work well when the objects in the scene are small in relation to the wavelength. Therefore, they are ideal at long wavelengths for scenes of a few dozen meters, but when you are dealing with the centimeter or millimeter wavelengths used by military radars, for example, and exploring large scenes, these methods are no longer suitable. Other methods, known as "asymptotic," have been developed to consider terrains of several hundred kilometers and short-wavelenth electromagnetic waves.

The simulation method is based on the laws of geometric optics [GO] and those of the Physical Diffraction Theory [PDT]

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A partner speaks out

Jean Latger / OKTAL SE: "Predicting complex electromagnetic interactions"

Jean Latger / OKTAL SE:
"Predicting complex electromagnetic interactions"