Abstract: For motion compensation of SAR images by means of an attitude and heading reference systema mean track angle (.psi..sub.T) flight is selected as desired flight direction;an acceleration (a.sub.x "(t)) is turned through a drift angle (.psi..sub.D) in the direction of a desired flight path;the speed (v.sub.xo '(t)) in the desired flight direction is calculated from a ground speed (v.sub.G (t));a variation of the relative speed (v.sub.x '(t)) in the desired flight direction is calculated by an integration of the acceleration (a.sub.x (t));a relative change of the across heading horizontal position (P.sub.y (t)) is calculated by a double integration of the across heading horizontal acceleration (a.sub.y '(t)), and an actual slant range of the aircraft to an illuminated terrain strip (R.sub.i '(t)) is calculated for each range gate in a manner known per se.

Abstract: A method and an apparatus are provided for calibrating a spectrometer, in particular a Fourier transform spectrometer (FTS), in particular for the infrared spectral range. At least four black body radiators of different temperatures are provided, which are arranged horizontally, i.e. parallel to the surface of the earth, thereby avoiding temperature gradients due to convection. The temperature of the at least four radiators is determined by means of the calibrating method without a separate measurement. In the method according to the invention, at the same time the absorption of the atmosphere is considered as a characteristic of the spectrometer, thereby eliminating separate measurement and correction thereof. In addition, for Fourier transform spectrometers the calibration is carried out by means of complex spectra.

Abstract: The invention relates to a procedure for measuring angles and angular characteristics, i.e. the interdependence between the angular deformations or displacements of structural parts and the acting forces or torques by means of a gyro. In the procedure the measurements can be carried out by means of a single gyro and result in a high measurement accuracy. It requires a repetitious execution of a multitude of measurements and in addition to the registration of measurement data and measurement times, the registration of reference data which are in definite connection with the angles to be measured (R-data). From the differences of the gyro measurement data and the measurement times for equal R-data the gyro measurement errors are computed and compensated accordingly.

Abstract: In a method of extracting phase errors caused by the atmosphere in the backscatter signal of an on-board coherent imaging radar system from radar raw data, firstly to image areas with different backscatter ratios over a predetermined period of time consecutive azimuth spectra are continuously formed. Thereupon, a frequency offset (.DELTA.F(t)) of the backscatter ratio component is obtained by determining the location of the maximum of the correlations between two respective immediately consecutively formed azimuth spectra. Then, a double integration for the difference of the frequency offset (.DELTA.F(t)) and a desired value (.DELTA.F.sub.soll) of the frequency offset is carried out, the frequency offset desired value (.DELTA.F.sub.soll) being determined either from the carrier forward velocity (V.sub.v) or by a low-pass filtering of the frequency offset (.DELTA.F(t)), and finally for standardization the result of the double integration is multiplied by a constant (2.pi./.DELTA.

Abstract: A receptacle includes a receiving chamber into which an injection fluid is to be injected. An injection unit includes a syringe having a needle adapted to pierce a diaphragm of the receptacle. The injection unit has a second needle [(28)] that may be advanced through a further diaphragm into a return chamber of the receptacle. The second needle is secured to a sliding pipe coupled to the syringe via a coupling means. Both needles are advanced simultaneously into the receptacle. Then, the syringe is ejected by moving the syringe plunger. The liquid volume displaced from the return chamber reaches the rear barrel chamber via the sliding pipe, the volume of the rear barrel chamber increasing by the amount in which the injection fluid has been ejected, subtracting the volume of the plunger rod. The exchange of liquid is supported by the suction effect of the partial vacuum generated by the lowering of the syringe plunger. The fluid of the injection device is sealed tight against the environment.

Abstract: In a method for correcting range migration in image generation in synthetic aperture radar (SAR) to eliminate the entire range migration or the residual range migration left by a conventional focussing method, prior to the range compression the data are transformed to the range-Doppler domain and there multiplied by a specific two-dimensional phase function; after an additional range Fourier transformatioin the range compression is then carried out with a specifically modified range transfer function and thereafter a range inverse Fourier transformation performed. Furthermore, a corresponding residual phase error is corrected. In addition, the data can if necessary be segmented in range or a range precompression performed.With the method according to the invention the range migration is completely eliminated without having to perform an explicit interpolation.

Abstract: It is a problem of pyrometric temperature measuring of melts in a vacuum that the material of the melt will be deposited on mirrors, windows and other optical devices so that the radiation will be screened more and more effectively, the closer it comes to the pyrometer. In order to avoid vapor desposition in the path of radiation, a grating arrangement is provided between the melt and the pyrometer, which focusses the incoming radiation and concentrates it onto the pyrometer. The grating arrangement is partly permeable to the molecules of the melt material. The direct path between the melt and the pyrometer is blocked by a screen. In this way, vapor deposition on the window prefixed to the pyrometer are avoided, while the radiation can reach the pyrometer.

Abstract: In a method for bit detection at the receiver end of differentially coded binary or quaternary PSK signals in differential-coherent demodulation, first received, processed signals (Y.sub.n) are supplied parallel to L symbol detectors (S1 to SL) of the order j (j=1,2,3, . . . , L; (L>1)). Then the conjugate complex signals (Y*.sub.n-1, Y*.sub.n-2, . . . Y*.sub.n-L), which are delayed by j symbol periods, and the unchanged, processed input signals (Y.sub.n) are multiplied in multiplication elements (M) to non-quantized output values z.sub.n.sup.(j) of the L symbol detectors and are subsequently complex conjugated. Thereafter, already detected, regenerated PSK symbols (a.sub.n-1, a.sub.n-2, . . . a.sub.n-L+1), delayed by time delay elements (T), are correspondingly fed back, and from this a symbol (a.sub.n) is determined, for which the sum of the squared distances .vertline.z.sub.n.sup.(j) -.epsilon.a.sub.n a.sub.n-1 a.sub.n-2. . . a.sub.n-j+1 .vertline..sup.2 with j=2,3, . . .

Abstract: An optical interferometer used for measuring the rotational angle or the anglular position of a rotating object, in which a path deflection is caused by means of the rotation of a reflector, the rotational movement of which is coupled with that of the object to be measured and thus is synchronous with its rotation. Furthermore, a laser beam is introduced into the interferometer. The path deflection caused by the rotation of the retro-reflector creates in the introduced laser beam varying interferences of defined wave length, which are proportional to the rotational angle of the reflector and of the object to be measured which drives it. Furthermore, the angular resolution is inversely proportional to the wave length of the laser beam.

Abstract: In a method for generalizing the conventional Viterbi algorithm, in which the transition costs are formed in a metric increment unit (TMU) and adding, comparing and selection are performed in a succeeding add-compare-select (ACS) unit, the difference costs from two arriving paths are calculated for each individual state, the reliability information at the beginning of each path being set to the highest value. Then the reliability value of the path with the least costs is updated at the points where the information points differ from the competing path, updating being performed in accordance with a table, and where the prior value of the reliability information and the difference costs are inserted into the table as the new input values. Then this new value is taken from the table and is stored, together with hard decisions, as path memory, where storage can be in the form of fixed or floating point values.

Abstract: For the imaging of terrains with varied ground reflectivity, azimuth spectra continuously following each other in time are formed over a set period of time in a method for extracting motion errors of a platform carrying a coherent imaging radar system from raw radar data. By determining the position of the maximum of the correlation between two azimuth spectra formed immediately following each other in time, the frequency shift of the ground reflectivity part is obtained. Then a separation of a velocity V.sub.v (t) in the forward direction from an acceleration V.sub.b (t) in the direction of LOS of the antenna is performed by filtering and the acceleration V.sub.b (t) obtained is subjected to normalization after two-fold integration, by means of which the displacement in LOS, i.e. the motion errors in the line of sight direction of the antenna, is obtained.

Abstract: A process for manufacturing a fiber reinforced tubular member having flanges at opposite ends thereof includes the steps of applying a winding including a plurality of fiber strands in an uncured curable matrix to a core element having a pair of spaced outwardly extending spreader elements thereon so as to form a central winding portion and a pair of conical winding portions on the core element; applying a forming tool to the winding between the spreader elements, the forming tool having a tubular inner surface, opposite outwardly extending end faces and transition edges therebetween; applying resilient outward pressure to the winding so as to urge the winding against the forming tool along the transition edges; uniformly applying the fiber from the conical portions of the winding to the end faces of the forming too; and curing the matrix.

Abstract: In order to improve a combustion engine for hydrogen comprising a main piston which is displaceable in a main cylinder in a stroke direction between a top dead center, forming a minimum main cylinder chamber with the main cylinder, and a bottom dead center and hereby performs a suction stroke, a compression stroke, a displacement stroke and an exhaust stroke, such that the problems of early ignition are avoided without any internal mixture formation with late injection being required, it is recommended that an auxiliary piston and an auxiliary cylinder be provided for movement relative to one another so as to be in equal phase and synchronous with the main piston and the main cylinder, that the auxiliary piston and the auxiliary cylinder define with one another a cylinder chamber varying between a minimum cylinder chamber in the top dead center and a maximum cylinder chamber in the bottom dead center, that the minimum cylinder chamber communicate with the minimum main cylinder chamber via a passage and that t

Abstract: In an optical switching arrangement comprising a laser, an electrooptical phase modulator formed as a two-arm interferometer, and a second two-arm interferometer as a multistable element, the second interferometer is formed with interferometer arms having optical pathlength differences of the order of magnitude of 10.sup.4 times the wavelength of the light from the laser and has at least one signal output arranged parallel to a further output; the further output is connected to a photodiode the output voltage of which is amplified and then used to control the current supply of the laser. The wavelength of the light emitted by the laser is variable by changing the control voltage of the modulator or the bias voltage of the current supply of the laser so that the output signal alternates between two stable interference signals.

Abstract: In a device for the ground-based simulation of operations capable of being performed in the direction of or around the three axes of an orthogonal coordination system of a manipulator usable in space by a model of a space vehicle, easily movable carriages are each guided in rails extending in the y-direction and disposed on a horizontal support frame, and a deflection roller is disposed on each, over which are guided ropes fastened with one free end on opposite sides of at least one segment of a simulated manipulator, in fact laterally offset in respect to the longitudinal segment axis and the center of gravity of the segment. Furthermore, the ropes are fastened, following an appropriate guidance over a plurality of deflection rollers and associated counterweights, with their other ends on the associated carriage.

Abstract: It is a problem of pyrometric temperature measuring of melts in a vacuum that the material of the melt will be deposited on mirrors, windows and other optical devices so that the radiation will be screened more and more effectively, the closer it comes to the pyrometer. In order to avoid vapor deposition in the path of radiation, a grating arrangement is provided between the melt and the pyrometer, which focusses the incoming radiation and concentrates it onto the pyrometer. The grating arrangement is partly permeable to the molecules of the melt material. The direct path between the melt and the pyrometer is blocked by a screen. In this way, vapor deposition on the window prefixed to the pyrometer are avoided, while the radiation can reach the pyrometer.

Abstract: For positioning a liquid sample which is held together by surface tension to form a drop, a plurality of lances is provided that are directed onto the sample from different spatial directions. Sintered bodies are provided on the lances, from which gas escapes. The escaping gas prevents a contact between the sintered bodies and the sample. The lances are positioned so close to the sample that indentations are formed in the latter.

Abstract: In order to so improve a high-frequency-excited, diffusion-cooled waveguide laser comprising a folded, unstable laser resonator with a first resonator axis branch and a second resonator axis branch, a folded, optical waveguide with a first waveguide branch and a second waveguide branch penetrated by the first and the second resonator axis branch, respectively, in their longitudinal direction, and each having two spaced, optical waveguide surfaces, and at least one reflection element with a reflection surface coupling the waveguide branches with one another, that as low reflection losses as possible occur with the folding and that the laser is as compact as possible, it is proposed that the two waveguide branches be coupled with one another at a first end by a single, first reflection surface, each with single beam reflection thereat, in that the two resonator axis branches intersect at their point of impact on the first reflection surface and that the two waveguide branches be curved in the direction towards

Abstract: A propeller for an aircraft or fan comprises an even number of propeller blades, at least six in number, which are unsymmetrically arranged around the axis of roation of the propeller in two circumferentially equidistantly spaced groups of at least three blades each. Each blade of each group is paired and longitudinally aligned with a respective blade of another group at the opposite side of the axis of rotation of the propeller, and each two next adjacent blades in each group are offset relative to each other by a spacing angle of between about 15.degree. and 40.degree.. For a selected speed of rotation of the propeller corresponding to a particular blade-tip Mach number, the magnitude of the spacing angle is inversely related to the magnitude of that blade-tip Mach number, for effecting a reduction of the level of the rotational sound harmonics by interference.

Abstract: The invention relates to the use of alloys containing50 to 70% by weight of nickel,10 to 40% by weight of chromium,3 to 10% by weight of aluminum,4 to 10% by weight of titanium and1 to 3% by weight of silicon,which alloys have a coefficient of thermal expansion .alpha. in the range of from 12 to 16.times.10.sup.-6 K.sup.-1 between 293 and 1370 K, as an adhesive layer bonding alloys based on nickel or titanium to a ceramic, and to processes for the preparation of said alloys.