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.

Clock recovery circuit with matched oscillators

Abstract: The circuit comprises a first and a second voltage-controlled oscillator (4, 14) having identical characteristics. The first oscillator (4) is incorporated into a frequency synthesis loop (3) in such a way as to oscillate, in response to a first control voltage (V₁), at a frequency equal to a reference frequency multiplied by a number N. The second voltage-controlled oscillator (14) is incorporated into a phase tracking loop (13) which, when it is activated, locks its oscillation phase relative to that of the received data signal (SD). The second oscillator (14) delivers the recovered clock signal (CLK₂). A comparator (20) determines whether the frequency of the second oscillator (14), divided by N, satisfies the condition of not deviating from the reference frequency by more than a predetermined limit value. The phase tracking loop (13) is activated only when the said condition is satisfied, and the first control voltage (V₁) is fed to the control input of the second oscillator when the said condition is not satisfied.

Liquid storage reservoir with capillary confinement

Abstract: The reservoir, usable more especially in a satellite, comprises a liquid outlet passage having a surface tension confinement device defining a buffer zone communicating with the outlet passage and, through orifices and a meniscus rupture zone, with supply ducts provided along the wall of the reservoir. The orifices are capillary and are provided in a wall situated in the immediate proximity of the point of drawing-off through the outlet passage (12), defining, with a capillary storage volume, a dead space of small volume.

Beagle 2: The exo-biology lander on ESA's 2003 Mars Express mission

Abstract: The 60 kg Beagle 2 lander for ESA's 2003 Mars Express mission will be described. Beagle 2 will search for organic material on and below the surface of Mars in addition to a study of the inorganic chemistry and mineralogy of the landing site. The lander will utilize a mechanical mole and grinder to obtain samples from below the surface, under rocks, and inside rocks. Such samples will be returned to the lander for detailed analysis. Analysis will include examination of samples and rocks and soils with an optical microscope and X-ray Spectrometer and Mossbauer Spectrometers as well as a search for organics and a measurement of their isotopic composition. The lander systems design as well as the experiment configuration will be described along with the status of the project.

The SOUT optical intersatellite communication terminal

Abstract: Optical communications links between satellites promise to become an important element of future space infrastructure and are the subject of considerable development in Europe. Major advantages over conventional microwave links are low mass and power and smaller size leading to easier accommodation on the satellite. The Small Optical User Terminal (SOUT) is an optical communications package for interconnecting a low earth orbiting satellite to future optical data relay terminals and is the subject of an ESA development programme led by MMS (UK). The baseline terminal has a data rate of 2 Mbps over the return interorbit link and a mass of around 25 kg. The terminal configuration uses a unique combination of a periscopic coarse pointing assembly, refractive telescope, passive antivibration mount, combined acquisition and tracking sensor, and fibre coupled lasers and receivers. The paper discusses the design aspects for an asymmetric optical link based on the SOUT, covering link budgets, pointing, acquisition, and tracking and communications performance. Key SOUT subsystems are described and the structural and thermal configuration which allows these features to be combined in a compact unit is reported.

Method and apparatus for active damping of vibration

Abstract: For active damping of vibration at a location subjected to a primary vibration field, a vibratory wave is generated by adaptive filtering of a reference signal and interferes with the primary field at the location. The residual amplitude of vibration at the location is measured, and filtering is adapted automatically to cancel the residual amplitude as measured. The reference signal is divided into a plurality of individual reference signals that are sine-shaped each containing only one of the plurality of frequencies at which the primary field presents a significant energy, with each individual signal being subjected to a respective adaptive digital filter, and the vibratory wave is generated from the sum of the individual filtered signals. An apparatus for implementing the method comprises n processing paths or channels, each having an actuator driving a digital filter, fed with a sine-shaped signal at a frequency corresponding to a concentration of vibratory energy to be damped.