Abstract: In the inventive aircraft based or spacecraft based radar system with synthetic antenna aperture (SAR=Synthetic Aperture Radar) a transmit antenna and a receive antenna are provided according to a bistatic radar, which are arranged above the earth's surface, physically separate and on different platforms of which at least one is moving, so that a relative movement results between the transmit antenna and the receive antenna. Either the transmit antenna, the receive antenna, or both antennas are designed for ambiguity suppression. The radar system according to the invention is useful particularly for the systematic imaging of the earth's surface.

Abstract: In a method for the detection, localization and velocity determination of moving targets from raw radar data from a coherent, single- or multi-channel image system (SAR), for representing the surface of the earth with different backscatter ratios, chronologically successive azimuth spectra are continuously formed during a defined period of time and a frequency shift of the backscatter ratio portion is obtained by determining the position of the maximum of the correlations between respectively two azimuth spectra formed chronologically directly in succession. Then the frequency shifts of the entire raw radar data set are evaluated for producing a frequency shift map.By searching for values deviating from the nominal Doppler rate in the Doppler rate map, a respective moving target is detected and the center of an image of the detected moving target is formed from this.

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: An antenna for an electronic projectile detonator. A desired antenna pattern which is rotationally symmetrical to the longitudinal axis of the projectile is produced by designing the antenna as a dipole which is fed via a coaxial line and which is decoupled from the feeder line by a .lambda./4 wave trap. The dipole is realized by a frustoconical widened portion of an extension of the inner conductor of the coaxial feeder line, which widened portion constitutes the detonator head in the tip of the projectile and coincides, as regards position and direction, with the longitudinal axis of the projectile at the feed point of the antenna, and the wave trap which is also designed to be rotationally symmetrical to the longitudinal axis of the projectile.

Abstract: In a projectile or rocket having a metal outer shell and including a proximity or influence detonator which operates with electromagnetic waves, particularly according to the reflected beam principle, and a directional antenna with a rotationally symmetrical radiation diagram for said detonator, the antenna is constituted by a circular slot which is coaxial with the longitudinal axis of the projectile or rocket and the antenna is excited with a line or cavity resonator disposed in the projectile or rocket and connected between the detonator and the antenna.