Abstract: A towed decoy arrangement for a craft with a decoy towed by the craft. Threatening signals are received by the craft and a noise signal is generated which is converted up to a frequency which is rapidly attenuated in air and sent to the towed decoy. In the decoy, the received signal is transformed into the noise signal by shifting it to the frequency of the threatening signal. Then the signal is transmitted from the decoy.

Abstract: A method of estimating target signals (dc or low frequency signals) by a dynamical fluxgate sensor and a low-power fluxgate magnetometer operating according to the method. The sensor is pre-biased with a periodic bias signal in the form of a superposition of a square wave and a triangular wave. The change in residence time statistics in the stable state of the sensor is analyzed for estimating the target signals.

Abstract: A method for dynamically verifying a multiple beam antenna placed on a craft including a device for determining the position and course of the craft and a transmitter that via the antenna can emit pulsed signals. At least two transponders are placed in different directions round a measuring area with each transponder receiving a pulsed signal of at least one frequency, different for the different transponders, from the antenna. The transponders are adapted to send, after receiving the pulsed signal, a corresponding pulsed signal to the measuring station in such a manner that the transponder sending the signal can be determined at the measuring station which evaluates how well the antenna has managed to direct the radiated energy in the desired directions.

Abstract: A method for determining position and velocity of targets from signals scattered by the targets using a first and a second station each including a transmitter/receiver of electromagnetic or acoustic signals. First, mono-static measurements are carried out from each station, and also a bi-static measurement between the stations. The two mono-static measurements are used to calculate a number of target candidates with 2-dimensional position and 2-dimensional velocity. These target candidates are tested against the result of the bi-static measurement and the target candidates which are found in all measurements with suitable error margins are retained.

Abstract: A distribution network which can be an active power splitter or an active power combiner or alternatingly power splitter and such a power combiner. The power splitter consists of two distributed amplifiers with a common input and one output each, and the power combiner consists of two distributed amplifiers with one input each and a common output. For the power splitter, a switching element is connected between each connection point on the outputs of the amplifying elements and ground, and for said power combiner, a switching element is connected between each connection point on the inputs of the amplifying elements and ground, the switching elements being optimised to take, depending on a control voltage, one of two distinct states. A first state corresponding to a capacitance and a second state corresponding to a low impedance short circuit.

Abstract: The present invention relates to a system for using signals scattered by targets to determine position and velocity for each of the targets and comprises a set of transmitters and receivers of electromagnetic or acoustic signals, said transmitters and receivers dispersed to known points. Each pair of transmitter and receiver, monostatic or bistatic, is named a measuring facility. The ranges of the transmitters are chosen so that a target at an arbitrary point within the position space can be measured via scattering in the target by at least four measuring facilities. For each measuring facility, target detection occurs with constant false alarm rate in the form of probabilities over resolution cells with regards to range and Doppler velocity and conceivable targets are placed in a 2-dimensional linear space belonging to the measuring facility.

Abstract: A device for screening interfering radiation from a radiation source from reaching a radiation receiver. The device includes a sensing device determining the position and orientation of the radiation receiver relative to the radiation source; a matrix, positioned in front of the radiation receiver, of elements which can adopt a varying transmittance and which cover the solid angle within which it is desirable to screen interfering radiation; and control equipment which calculates in what position relative to the radiation receiver a radiation obstacle is to be placed to be able to screen the radiation source and which controls the elements of the matrix in such a manner that the matrix forms a partial or complete radiation obstacle in the estimated position.

Abstract: An artificial line, particularly an artificial electric line, and specifically an artificial line having a constant group delay in a wide frequency range (octave bandwidths). The artificial line comprises two identical inductors of the magnitude L connected in series and having a mutual inductance M, and a capacitor of the magnitude C1 over the inductors and a shunt capacitor C2 to earth. The element values as a function of the cut-off frequency fc and the characteristic impedance Z0 are selected according to specific equations. The artificial line can then be realized as a continuously tunable artificial line or as a self-switched artificial line. The two types of artificial lines can also be cascade-coupled.

Abstract: A Synthetic Aperture Radar (SAR) system and method capable of detecting moving targets which includes a platform that moves over a number of objects, such as a ground surface, and supports radar equipment which reproduces the objects by means of a fast backprojection synthetic aperture technique via at least two antennas without requirement as to directivity or fractional bandwidth. The imaging process is divided into three steps which are carried out in a determined order, the steps and the order being formation of sub-aperture beams at one speed, performing clutter suppression, and detection of moving targets.

Abstract: Antenna carrier comprising antenna elements to be connected to an air vehicle, said antenna carrier projecting from a mounting area forwards or rearwards seen in the travelling direction of the air vehicle. The antenna carrier comprises an elongate front part (3), which comprises a flexurally rigid shell (6); an elongate, pliable mounting part (2), which at its front end (11) connects to the front part (3); a front mounting point (13) via which a front part of the mounting part (2) is connected to the air vehicle; and a rear mounting point (14) via which a rear part of the mounting part (2) is connected to the air vehicle. The flexural rigidity of the shell (6) of the front part and the mounting part (2) is adjusted in such manner that the eigenfrequencies of the antenna carrier are well separated from the critical eigenfrequencies of the air vehicle.

Abstract: A method of detecting, by means of a SAR radar, objects that change with time within a ground area. The SAR radar is supported by a platform in essentially rectilinear motion during a synthetic aperture and the ground area is reproduced at least twice in succession from different synthetic apertures. A two-dimensional SAR image is generated from each synthetic aperture. The SAR images are matched with each other by a method in which each image position in one image is associated with the same ground area in the other image, the images being filtered, knowing location data for the antennae and based on the fact that the cylinder geometry of the SAR images is projected onto the ground surface, so that only common spectral components of the reflectivity of the ground are extracted and used in the matching.

Abstract: The present invention relates to a radar system which comprises a platform which moves over a number of objects. The number of objects can be very large and the objects can appear in the form of, for example, a ground surface. The platform supports radar equipment which reproduces the objects by means of synthetic aperture technique (SAR) via at least one antenna without requirements as to directivity or fractional bandwidth. Moreover, the movement of the platform is, during the recording of data for a SAR image, essentially rectilinear and uniform. The invention is characterized mainly in that it comprises a signal-processing device which records received radar echoes from each transmitted radar pulse and records or calculates the position of the used antenna or antennae, and which calculates a one-parameter quantity of two-dimensional SAR images as a function of two image co-ordinates where the parameter is the relative speed. Here use is made of the fact that each object, i.e.

Abstract: A method for generating a liquid mist to produce phantom targets or camouflage. A liquid is launched by a water cannon (1) at high velocity and initially the liquid is held together in a liquid packet (2) in order to decompose after a certain distance, under the effect of the air resistance, and atomize into small liquid drops to form a liquid mist (3).

Abstract: The present invention relates to a method for generating a three-dimensional image of a ground area by means of a radar with a synthetic aperture, a SAR radar, which is supported by a platform moving in an essentially rectilinear manner. The method is characterized by the following steps. Advancing the platform such that at least two images of the ground are created with great difference in the angle of illumination. Transmitting radar pulses with a fractional bandwidth which is larger than or equal to 0.1, and using in the computations an aperture angle which is larger than or equal to 0.1 radians. Detecting the reflected radar pulses with amplitude and phase. For each pulse, measuring and storing the position of the antenna that transmits and the antenna that receives the pulse. Computing a two-dimensional SAR signal per synthetic aperture.

Abstract: A new compound, 1,1-diamino-2,2-dinitroethylene suitable for use as an explosive, as well as an intermediate for preparing the compound consisting of a heterocyclic 5- or 6-ring of the general formula wherein n=at least 1. The compound is prepared by nitrating a heterocyclic 5- or 6-ring containing the structural element wherein Y is an alkoxy group, with a nitrating acid at a low temperature, preferably 0-30° C., and selecting the acidity of the nitrating acid for obtaining a substantial yield of a product containing the structural element and hydrolyzing said product in an aqueous medium for separating 1,1-diamino-2,2--dinitroethylene which is recovered as a precipitate.

Abstract: A new chemical compound suitable for use as an explosive consists of guanylurea dinitramide having the formula which is also suitable as a main essential component for explosives, especially propellants; a pressed rocket motor charge; and a gas-generating component in gas generators for vehicle safety equipment, such as airbags.