Matra

About: Matra is a based out in . It is known for research contribution in the topics: Signal & Detector. The organization has 1330 authors who have published 1216 publications receiving 17967 citations.

Microwave Humidity Sounder (MHS) antenna

Abstract: MHS is an atmospheric humidity sounder providing humidity profile sounding capability in the 89 - 190 GHz range. It is a five channels of self-calibrating microwave radiometer. Together with the complementary instrument AMSU-A, MHS provides the operational microwave sounding capability for the European METOP series and American NOAA-N onwards- meteorological satellites. The MHS instrument is being developed under contract to EUMETSAT. The present paper focuses on the electromagnetic design and development of the 22-cm diameter rotating antenna of the MHS instrument operating at 89, 157, 183 and 190 GHz. The primary feed network so-called Quasi-Optical Network (QON) is an essential part of the overall antenna. It has to provide not only the low-los frequency separation of the four bands but also the proper antenna illumination in amplitude and phase in order to satisfy the required resolution and high beam efficiency. This equipment has been undertaken by the MHS Receiver Team in Toulouse (Matra Marconi Space-France) using state of the art technologies. After a presentation of the antenna concept, the Quasi-Optical Network design is detailed and the electrical measurements results are presented. The antenna radiation pattern measurements at instrument level are used to derive the overall antenna electrical performance.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Oxidation and particle deposition modeling in plasma spraying of Ti-6Al-4V/SiC fiber composites

Abstract: Plasma spraying is known to be a promising process for the manufacturing of Ti/SiC long-fiber composites However, some improvements remain for this process to be applied in an industrial route These include: oxygen contamination of the sprayed material through that of titanium particles before and during spraying, damage to fibers due to a high level of thermal stresses induced at the spraying stage, adequate deposition of titanium-base powder to achieve a low-porosity matrix and good impregnation of the fiber array This article deals with work that resulted in a threefold study of the process Oxidation was studied using electron microprobe analysis of elementary particles quenched and trapped into a closed box at various given flight distances Oxygen diffusion phenomena within the particles are discussed from a preliminary theoretical approach coupled with experimental data Isothermal and thermomechanical calculations were made using the ABAQUS code to determine stresses arising from contact of a liquid Ti-6Al-4V particle onto a SiC fiber On the scale of the sprayed powder flow, a two-dimensional new type of model simulating the deposition of droplets onto a substrate was developed This new type of model is based on a lattice-gas automaton that reproduces the hydrodynamical behavior of fluids

High Frame Rate, Low Latency Hardware-in-the-Loop Image Generation — An illustration of the Particle Method and DIME

Abstract: New computing architectures based on the DIME standard have been previously introduced which allow for processing of high frame rate imaging systems which may also need low latency capability, a common requirement for HWIL systems. This paper is presented in two sections: To achieve future realism in image generation systems for hardware-in-the-loop (HWIL) testing a significant increase in processing power is required, but additionally a suitable architecture is essential to provide low latency response on the data flow. Nallatech previously introduced DIME as a novel platform for HWIL systems which is capable of handling sub-frame latencies and greater than 100 Hz frame rates. We will demonstrate the system operating on traditional complex imaging problems, such as large convolution masks of 13 X 13 and also on new image generation techniques such as the particle method which is being developed by Matra British Aerospace Dynamics UK (MBDUK). MBDUK are proceeding on upgrading existing HWIL image generation systems for real-time particle models, to higher frame rates and increased complexity. Using Nallatech's latest DIME based architectures, models containing thousands of individual particles can be created at frame rates over 100 Hz and a resolution of 1024 X 1024 oversampled 4 times. This is possible because particle models exhibit high levels of parallelism ideal for exploiting the architecture of an FPGA. This paper will demonstrate the versatility of these particle models to create highly realistic signatures in terms of spatial dynamics and IR signature. Particle models are ideal for simulating dynamic objects such as flares, exhaust plumes, fires and explosions.

Method for checking profile dimensions of elongate products

Abstract: The method for optical checking of the profile cross section of an elongate product consists of transversely illuminating the profile with a laser beam with a predetermined angle of incidence, forming at least one image of the cut, and reconstructing the profile via image analysis. The method is characterised by the fact that the laser beam is dynamically focussed along the profile.Special points of the profile are illuminated with sufficient excess intensity to locally saturate a picture spot of a camera (20) delivering the image. The centre of the spot is given by its centroid. The illumination of the rest of the profile is an order less than the resolution of the camera.