Abstract: A method is suggested for robust estimation of a subset of carrier phase integer ambiguities for precise ionospheric delay estimation. The advantages of this method are the precise estimation of receiver and satellite biases, an increase in the number of reliably fixable ambiguities, and an improved accuracy for the ionospheric delay estimation.

Abstract: A new method for bias estimation on multiple frequencies with a Kalman filter is proposed. It consists of four steps: First, a least-squares estimation of ranges, ionospheric delays, ambiguities, receiver phase biases and satellite phase biases is performed. The code biases are absorbed in the ranges and ionospheric delays, and a subset of ambiguities is mapped to the phase biases to remove linear dependencies between the unknown parameters. In a second step, the accuracy of the bias estimates is efficiently improved by a Kalman filter. The real-valued a posteriori ambiguity estimates are decorrelated by an integer ambiguity transformation to reduce the time of ambiguity resolution. Once the float ambiguities have sufficiently converged, they are fixed sequentially in a third step. Finally, a second Kalman filter is used to separate the receiver and satellite code biases and the tropospheric delays from the ranges.

Abstract: A method for estimating satellite-satellite single difference biases is described. The method uses an ionosphere-free mixed code-carrier combination of maximum ambiguities discrimination defined at the ration between wavelength and noise standard deviation. The accuracy of the biases estimation is further improved by an additional ionosphere-free mixed code-carrier combination of time-difference measurement that is uncorrelated with the first combination. Finally, an alternative method is based on a combination of carrier signals in a common frequency band which allows estimating the biases individually.

Abstract: A movement device (1) having a Stewart platform includes a movable platform (9) that has platform joints (8) connecting it in an articulated manner by at least six rods (6) to a base (3). The rods (6) have base joints (7) resting in an articulated manner on carriages (4, 5) that can be displaced in the longitudinal direction on rails (2a, 2b) that are fixed to the base. Each carriage (4, 5) has a dedicated drive, and the carriages (4, 5) can be moved independently of one another. Exactly two rails (2a, 2b) are provided, and each rail (2a, 2b) supports at least three carriages (4a, 4b, 4c and 5a, 5b, 5c).

Abstract: A reflector antenna, in particular for the reception and/or transmission of signals from and/or to satellites. The reflector antenna according to the invention comprises a reflector arrangement for focusing antenna radiation in a focal plane together with an antenna array arranged in the focal plane, or in the vicinity of the focal plane, with a plurality of antenna elements. A control device is provided with a beamforming means. Through the control device, sub-arrays, comprising one or a plurality of antenna elements of the antenna array for the reception and/or transmission of antenna radiation, can be activated and deactivated. In the operation of the reflector antenna, a radiation lobe pattern is formed by means of the beamforming means for the reception and/or transmission of antenna radiation for a particular activated sub-array.

Abstract: The present invention relates to a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising plastic and/or carbon aerogels, and a process for the preparation of such molding materials. The molding material comprises highly porous open-cell plastic and/or carbon aerogels, obtainable by the sol-gel polymerization of organic plastic materials, optionally followed by partial or complete pyrolysis of the plastic aerogel obtained.

Abstract: The present invention relates to a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising plastic and/or carbon aerogels, and a process for the preparation of such molding materials.

Abstract: The present invention relates to a device and method for introducing solar radiation energy into a photoreactor. This reactor can be employed for performing photochemical or photobiological reactions, i.e., syntheses, decontamination, disinfection and treatment processes. The device is characterized in that the photoreactor consists of one or more transparent outer tubes irradiated with light from the exterior, the reaction medium being passed through the tubes and thereby exposed to the radiation, wherein one or more empty transparent tubes with a smaller diameter are provided in the interior of said outer tubes, especially in a concentric arrangement, and the reaction medium is passed through the gap formed between an outer and an inner tube or, in the case of several inner tubes, through the gaps formed therebetween.

Abstract: The present invention relates to a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising plastic and/or carbon aerogels, and a process for the preparation of such molding materials. The molding material comprises highly porous open-cell plastic and/or carbon aerogels, obtainable by the sol-gel polymerization of organic plastic materials, optionally followed by partial or complete pyrolysis of the plastic aerogel obtained.

Abstract: The present invention relates to a process for vapor-depositing zirconium dioxide on ceramic or metallic substrates, and the heat-insulating layers obtainable by such process.

Abstract: The present invention relates to a process for vapor-depositing zirconium dioxide on ceramic or metallic substrates, and the heat-insulating layers obtainable by such process.In particular, the invention relates to a process for vapor-depositing zirconium dioxide, optionally doped with rare-earth metal oxides or mixtures of such oxides, on ceramic or metallic substrates in a range of substrate temperatures of from 600 to 1550.degree. C. while the substrate is continuously rotated at a speed in the range of from 1 to 300 rpm, characterized in that, following the nucleation phase, the rotational speed and the temperature are adjusted to a range defined by the equations: ##EQU1## where T represents the substrate temperature in .degree. K, and .omega. represents the rotational speed of the substrate in rpm, wherein the rotational speed is varied continuously or discontinuously, or alternatively in alternating senses of rotation.