Abstract: A system is disclosed for determining the position of at least one target by triangulation, comprising two passive sighting devices which measure the intensity of radiation received along a sighting line which scans a vertical sighting plane. They are disposed at a distance from each other along the same vertical axis and are driven in rotation about this common axis so that their sighting planes merge. A circuit extracts the angular coordinates of the target, relative to each of the sighting devices, and computes the distance of the target by triangulation in the vertical sighting plane.

Abstract: A device is divulged for generating an infrared image, in which an electron beam having a section substantially equal to the area of a pixel formed from a material having high emissive power in the infrared, directly bombards this material. The energy of the beam is transformed into heat then into infrared radiation, in the material. Each pixel is supported by a slab of a material transparent to the infrared, which is heat insulating and deposited on a screen transparent to the infrared and heat conducting.

Abstract: The aircraft (1) incorporates means for emitting a conical light beam (14). The vessel (2) incorporates photosensitive cells (6) materializing the outline of the beam on the vessel, which is an ellipse (7). Means determine the equation of the ellipse (17) and, from this, landing data which are displayed on a panel (25).

Abstract: A cryostatic device is divulged for radiation detectors, disposed at the end of a cooled finger. A case, transparent to the radiation to be detected, at least in the vicinity of the detector, forms about the finger and the detector a heat insulating enclosure. An electric circuit brings the detected signal(s) outside the enclosure and radially immobilizes the end of the finger with respect to said case, because its substrate is a disk fast both with said case and with the end of the finger.

Abstract: In a box having an openable front face, plural fiber loop supports substantially flat and movable can be laid out parallel with the front face of the box. Connector bars are respectively attached to the supports and are used for two by two connecting the optical fibers. Slides on sliding rails attached in the box enable the supports to be translated together substantially perpendicular to the front face and completely outside the box. A support-bearing rod is rotatively mounted between the slides so as to turn the supports together outside the box and around an axis of rotation substantially parallel with the front face. The inside of the box is then accessible. Each of the supports can pivot around an axis perpendicular to the support so as to be cleared away from the other supports.

Abstract: A binary-to-bipolar converter converts two binary signals into positive and negative bipolar pulses alternately corresponding to a "1" logic state of two binary signals. The bipolar pulses are defined by the low output impedance states of two transfer gates. The main object of the invention is to reduce the transient trailing of the rear edges in the bipolar pulses. This can be obtained by delaying the drop from the low impedance state to the high output impedance state by means delaying control signals on the transfer gates, or by an integrator circuit applying calibrated pulses onto the output of the transfer gates, in response to the rear edges of the "1" logic states in the binary signals. The converter also calibrates the rise times of the bipolar pulses and allow the use of CMOS circuits upstream of the converter.

Abstract: A terminal is provided for transmitting data over a bidirectional analog channel with echo cncellation coupled to the reception timing, wherein, between an emission circuit and a reception circuit coupled to a bidirectional line by a hybrid coupler, an echo canceller synthesizes an estimated echo from samples of an analog emitted signal, sampled at the same frequency as the received signal, the sampling frequency being controlled by the reception circuit, which is not synchronous with the emission circuit. Such a terminal requires no interpolation filter at the input of the reception circuit and makes possible optimum coupling of the echo canceller with an equalizer.

Abstract: A tube for protecting and guiding an optical fiber is constituted by two tubes which are co-extruded and then stretched. The inner tube thus acquires a reduced coefficient of linear expansion, which is closer to that of glass. The outer tube protects the inner tube from fibrils appearing on its surface.

Abstract: A telephone circuit, which may be monolithically integrated, for supplying ringing signals to a subscriber's telephone line and for detecting an off the hook condition during ringing, including a logic control circuit connected to exchange components which control the supply of the ringing signals and determine their rhythm. The logic control circuit is connected to a circuit for detecting direct current on the line and a current comparator for generating a signal when the value of the line current exceeds a predetermined current value. This signal is also supplied to the exchange components via a transfer circuit to inform them that an off the hook condition has taken place. The logic control circuit is connected to a timing signal generator which synchronizes its functions with times in which the ringing signal has a zero amplitude, and is connected to a signal amplifier circuit which supplies the ringing signals to the line and to the transfer circuit.

Abstract: In a receiving station having an adaptive receiving antenna, a phasing system comprises a plurality of reception paths receiving telecommunications signals derived from the same useful signal combined in transmission with a disturbing signal having a frequency band outside the frequency band of the useful signal, via a plurality of primary sources of the receiving antenna. The phasing system includes a narrowband filtering circuit for filtering the overall telecommunications signal in one of the reception paths to derive a reference signal undisturbed by the disturbing signal and solely dependent on the useful signal. In phasing circuits respectively assigned to the reception paths, the useful signal alone is set to a phase as close as possible to the phase of the reference signal in order to obtain, after signal summing at outputs of the phasing circuits, a maximum power using signal mixed with an attenuated scrambling signal.

Abstract: A predetermined characteristic of each of incoming plesiochronous component signals in a time-division multiplexing equipment is derived at each stuffing time for transmission in the form of a stuffing bit in a respective stuffed signal to be multiplexed in a resulting signal. In a demultiplexing equipment receiving the resulting signal, the stuffing bit in a respective demultiplexed stuffed signal is sampled and simultaneously the predetermined characteristic of the plesiochronous signal outgoing from the demultiplexing equipment is derived at each unstuffing time. The sampled stuffing bit and the derived predetermined characteristic are compared in order to measure the transmission quality of a digital channel carrying the component signal through the two equipments. The predetermined characteristic is preferably the parity of the signal between two consecutive stuffing and unstuffing times.

Abstract: The invention relates to a photodiode with high speed response formed in a P type HgCdTe semiconductor substrate. On one face of this invention an N type doped zone is formed. A metallization is in contact with a layer of copper telluride Cu.sub.2 Te, disposed on the other face of the HgCdTe semiconductor substrate, opposite the PN junction. Such a photodiode, sensitive to the near infrared, has a low series resistance which confers thereon a high speed response.

Abstract: In an optical fiber cabling line where a grooved ring is axially drawn at a translational speed, there is provided a device designed to insert optical fibers in helical grooves of the ring. The fibers are unwound, are drawn through a rotating plate and converge following cone generating lines towards the device. In order to avoid the use of fiber-guides coupled directly in rotation with the ring, the device comprises a quill rotationally stationary and coaxial with the ring for laying the fibers into the grooves of the ring, and means, such as two worm screws set orthogonally to the ring, arranged after the quill in the travel direction of the ring and mechanically uncoupled from the ring for thrusting the fibers to the bottoms of the grooves. The worm screw also contributes to align the fibers as they leave the plate, with the ring grooves within the quill.

Abstract: A rotary and sealed connection for pressurized fluids is provided, including a first part that is secured, for example, to a fixed source of pressurized fluid and has a recess for communication therewith and through a second part, with a fluid-using rotary apparatus of revolution rotating about a shaft and extending through the first part through a passage, said second part having a degree of radial freedom and being held in position without play by a seal serving as a bearing. The annular space in the passage may thus be extremely reduced, thus avoiding any risk of extrusion of the seal.

Abstract: A step-by-step locating system for a digital bidirectional transmission link includes repeater pairs between a monitoring end equipment and a remote monitored end equipment. When a repeater pair is connected via a loop-back path to the monitoring end equipment thereby testing the repeater pair, the next repeaters are also connected to the monitoring equipment by closure of associated switches. Such a condition avoids the need for matching with maximum amplification gain in equalizers of the next repeaters, which could cause a fault in the regeneration of remote locate sequences or untimely looping in the next pairs after testing of the looped repeater pair. In practice, any interruption of the digital signal in remote locate sequences transmitted by the monitoring equipment does not exceed a width such that no matching with maximum gain is generated.

Abstract: The present invention relates to the transmission of digital information by means of a higher rate channel, the channel having a priori no phase relationship with the primary digital channel, the transmission method comprising chopping the digital stream into packets of p bits, associating with each packet a preamble comprising at least one synchronization word, transmitting the packets at the rate H.sub.i /p and on the reception side restoring the clock associated with the digital stream by dividing by p each time interval separating the arrival of two successive packets.

Abstract: In a device for CMI code decoding, a detector of certain transitions between pairs of the coded signal delivers a signal for synchronizing a clock recovery circuit. A decoding circuit receives the coded signal and the clock signal and delivers the decoded signal.

Abstract: A reserve device is provided for optical fibers, including a flat bottomed case with a core defining a recess having substantially the form of a closed loop omega, at the ends of which inlet and outlet channels are provided for the optical fibers, each fiber being protected by two tubular ducts leaving it bare, coiled about said core, said tubular ducts being immobilized in the inlet and outlet channels when the case is closed, said core including a central part integral with the case, surrounded by a removable ring intended to be removed after coiling of the optical fibers.

Abstract: An HgCdTe avalanche photodiode for use at ambient temperature comprises an Hg.sub.1-x Cd.sub.x Te crystal substrate in which x is chosen between substantially 0.35 and substantially 0.5, a PN junction is formed in the substrate with low concentrations in the vicinity of the junction, by impurity penetration from a polished and chemically etched surface and the P zone is illuminated. A guard band is provided around the PN junction. The dark current of the photodiode is less than 0.1 .ANG./cm2 at ambient temperature and the excess noise factor is less than 0.4. The photodiode of the invention is used for detecting signals transmitted along fluorated glass optical fibers, for example.

Abstract: In order to spread optical fibers emerging from an end of cable and to firmly attach the cable end with ends of protective jackets in which the spread fibers are strung, the following steps are performed by means a spreading device including mainly a grooved hollow distributor. The distributor is fastened to a sawn off end of a grooved elongated ring in the cable by pinching a central armature emerging from the cable, by jaws housed in the distributor. A split ring is strung around a grooved revolution portion of the distributor. For each fiber, a longitudinal slot of the split ring and a respective groove of the revolution portion are superposed, the end of the jacket of the fiber is entered into the groove through the slot, and the jacket is forced into the groove by partially rotating the split ring so as to superpose the slot and another distributor groove.