Abstract: A vectorial magnetometer (1), measures the components of a magnetic field in three directions (Oxyz) using a scalar magnetometer (2). The field is periodically modulated in each of the directions by generators (Gx, Gy, Gz) which have a specific frequency for each direction and that power coils (Ex, Ey, Ez). Synchronous demodulation of the of the output signal of the scalar magnetometer (2) for each of the three frequencies permits the relative continuous component of each axis to be found. The vectorial magnetometer (1) is characterised in that it has means (Dx D′x, Dy D′y, Dz D′z) that can carry out a double demodulation for phase and quadrature for each of the frequencies and processing means (70) that use the continuous component modules for phase and quadrature to calculate a transfer function of the scalar magnetometer at the frequency in question, and to apply this function to the correction of the components.

Abstract: A method for 3D modeling of the impedance of a heterogeneous medium from recorded data corresponding to waves coming from the heterogeneous medium (such as a subsoil zone), in response to (for example elastic or electromagnetic) waves transmitted therein, and from an a priori 3D model of this heterogeneous medium, knowing the position of various impedance discontinuities of the medium, and after stratigraphic interpretation is disclose. The method comprises constructing a 3D geometric model comprising several foliated volumes (such as sedimentary units foliated by the deposition isochrones) with definition of the different sheets, constructing an a priori impedance model from this geometric model and from a plurality of impedance measurements taken at various depths of the heterogeneous medium (in a well for example), selecting a covariance model (exponential for example) along the sheets of the foliated volumes, and forming the optimum model by recorded data inversion using the a priori impedance model.

Abstract: A device for measuring components of a magnetic field includes a scalar magnetometer surrounded by at least two conductor windings supplied continuously with currents from different generators. A processing circuit demodulates the signal supplied by the scalar magnetometer and supplies signals corresponding to the components of the field to be measured along the axes of the conductor windings.

Abstract: The method relates to an optimizing method for determining the optimum shape of plates such as sheets of sheet metal, panes of glass, or other thin objects designed in particular to retract completely in order to leave a clear opening. To simplify the use of shaped plates that have already been predesigned, they are modified such that their shapes coincide substantially with a "screwable" surface chosen from the wide variety of existing surfaces that meet screwability criteria and can hence move in the space without changing position, except for their edges. Implementation of the method allows the various constraints that may exist in the design of such plates to be met.

Abstract: A coupled radio frequency field and light polarization magnetometer. The polarization direction P and the direction of the radio frequency field B.sub.1 are kept parallel to one another and perpendicular to the field B.sub.0 which is to be measured. The polarizer is connected to the coil, which produces B.sub.1, and the assembly is rotated by a piezoelectric motor.

Abstract: Resonance magnetometer with optical pumping using a monolithic laser. The laser (30) includes a single element (32) (crystal or fiber) whose length is modulated to provide both a wavelength and amplitude control.

Abstract: Resonance magnetometer with optical pumping using a monolithic laser. The laser (30) includes a single element (32) (crystal or fiber) ensuring whose length is modulated to provide both a wavelength and amplitude control.

Abstract: Slaved radio frequency field and light polarization magnetometer. The polarization direction (P) is slaved perpendicular to the field (Bo) to be measured, as well as the radio frequency field (Brf). Application to the measurement of weak magnetic fields such as the geomagnetic field.

Abstract: Optical pumping magnetometer with controlled polarization.This magnetometer comprises a linear polarizer (16), whose orientation is controlled (42,44) in such a way that the detection signal is at a maximum, no matter what the orientation of the field to be measured.Application to the construction of isotropic magnetometers.

Abstract: A magnetometer for precise measurement of weak magnetic fields involves a system which injects a plurality of light beams into a gas containing cell. An optical multiplexer receives the light beams emitted by a source and successively supplies a plurality of light beams which traverse a corresponding number of polarizers. The beams are subsequently injected into the cell 10 in the plurality of different directions in order to optically pump the gas. A detection device detects an electrical resonance signal and supplies a plurality of signals corresponding to the optical pumping beams.

Abstract: A magnetometer having three trirectangular trihedron windings (20x, 20y, 20z) which are put into service successively by a multiplexer (50). The means frequency (F.sub.m) of the three measurement signals is independent of the orientation of the weak magnetic field which is to be measured.

Abstract: An improved optical pumping magnetometer with sequential polarization for measurement of weak magnetic fields involves a device which sequentially modifies the polarization either in the direction of the polarization or from clockwise to counterclockwise circular polarization. As a result of the sequential modification of the polarization, the magnetometer for measurement of the weak magnetic fields has excellent isotropy while still retaining a simple construction and a small overall dimension to the device by using only a single cell.