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.

Method and device for preprocessing an acoustic signal upstream of a speech coder

Abstract: The input acoustic signal is subjected to high-pass filtering. The energy of the high-pass filtered signal is compared with that of the unfiltered signal in order to determine a state of the signal from among a first state for which the energy of the high-pass filtered signal is above a predetermined fraction of the energy of the unfiltered signal and a second state for which the energy of the high-pass filtered signal is below the predetermined fraction of the energy of the unfiltered signal. The high-pass filtered signal subjected to pre-emphasis of the high frequencies is addressed to the input of the coder when the signal is in its second state.

Real-Time Logic Revisited

Abstract: This paper redefines RTL within classical many-sorted logic with natural number and real arithmetic. In doing so, RTL is generalised in a number of ways. In particular, functionality is handled through the use of timed variables. Various models of time for RTL are discussed, and it is argued that, providing events satisfy a countable occurrence property, time in RTL can be continuous. A number of useful RTL theorems are stated, and it is shown that RTL can naturally express all the usual temporal requirements that are placed on real-time systems. RTL is compared with other timed logics.

Compact version of the Atmospheric Lidar Instrument (ATLID)

Abstract: ATLID is a spaceborne backscatter LIDAR using a solid-state Nd-YAG laser (106 micrometers wavelength) and a 06 m diameter telescope It is intended to fly on-board a polar platform satellite The selected concept consists in a lightweight scanning telescope associated to a contra-rotative flywheel A linear scanning (+/- 23 degree(s)) is used in order to achieve the required swathwidth (700 Km) The detector is a silicon Avalanche Photodiode The instrument has been compacted to a similar volume as for currently developed ENVISAT-1 instruments The thermal control is designed to be independent of the neighbor instruments, thus allowing ATLID to be mounted on a multi-instrument payload A breadboarding program has been initiated for critical parts of the instrument This paper describes the overall instrument architecture, as well as first breadboard results

Apparatus for producing continuously a fluid mixture of solids and liquids

Abstract: Eine Einrichtung zum kontinuierlichen Erzeugen einer flussigen Mischung von Fest- und Flussigstoffen hat zur Bildung einer Rotationsstromung einen rotationssymmetrischen Raum mit annahernd vertikaler Rotationsachse. Means for continuously producing a fluid mixture of solids and liquids to form a rotating flow has a rotationally symmetrical chamber with an approximately vertical axis of rotation. Um eine einfache aber zuverlassig arbeitende Mischeinrichtung zu schaffen, die ein vorherplanbares Mischergebnis liefert, auch wenn zeitweise ein sehr starker oder wesentlich schwacherer Strom vorliegen soll, wird vorgeschlagen, den rotationssymmetrischen Raum als Ringraum (13) mit einer innenseitigen Uberlaufkante (14) auszubilden und unterhalb der Uberlaufkante (14) ein trichterformiges Auffangbecken (18) vorzusehen, sowie oberhalb der Uberlaufkante (14) die Austragmundungen der Dosiereinrichtungen (52,53) der zu mischenden Stoffe vorzusehen. In order to provide a simple but reliable operating mixing device, which supplies a vorherplanbares mixing result, even when a very strong or substantially weaker current is temporarily present, the rotationally symmetrical space as an annular space (13) is proposed to form with an inside overflow edge (14) and below provide the overflow edge (14) to provide a funnel-shaped collecting tank (18), and above the overflow edge (14) Austragmundungen the metering devices (52,53) of the substances to be mixed. Die flussige Mischung soll am Ausgang des Auffangbeckens (18) wahlweise zu einem Mischbehalter (28) oder direkt zu einer Austragpumpe (27) gelangen. The liquid mixture is intended to pass at the output of the collecting basin (18) selectively to a mixing vessel (28) or directly to a discharge pump (27).

A demonstrator for an incoherent Doppler wind lidar receiver

Abstract: The knowledge of wind fields for a global terrestrial coverage and accurate altitude sampling is one of the main keys for improvement of meteorological predictions and general understanding of atmosphere behaviour. The best way to recover this information is remote sensing from space using low Earth orbit satellites. The measurement principle is to analyse the Doppler shift of the flux emitted by the space instrument and backscattered by the atmosphere. One of the most promising principle for Doppler shift measurement is the direct detection which does not need local oscillators. what significantly simplifies the design of such a space-borne receiver. ESA-ESTEC initiated at early 95' a programme called "lncoherent Doppler Wind Lidar (IDWL) technologies" for the study and bread-boarding phase. MMS won this contract proposing an original concept based on the use of a Fizeau high resolution interferometer working in the UV band. coupled with an intensified CCD. This concept is patented by MMS, as well as the special CCD timing sequence that will be depicted below. The programme begun by a study of the space-borne instrument in order to identify main constraints and define the receiver as could be for a flight model. A detailed performance model was established and parametric analysis allowed to optimise the concept in order to reach required performances. This study phase finally provided the definition of a bread-board for expected performances demonstration. Moreover, the Laser Signal Simulator (LSS) which is used to simulate the Lidar echo in term of amplitude as well as frequency modulation was defined at this step. The performances of this test support equipment are of main importance for the validation of the demonstrator design and performances. The second part of the study aimed at defining the derailed design of the demonstrator and associated test support equipment as well as initiating preliminary validation experiments on most critical technologies, like Fizeau interferometer which needs particularly high thermal stability and spectral resolution. At the end of this design phase. the test bench equipment begun to be manufactured and equipment test results preliminary assessed the study phase results. After integration, the correct operation and control of the overall test bench were assessed and performance tests were undertaken . The final conclusion of this programme aimed at up­dating the performance simulation software in order to refine expected performances for the future flight instrument.