Deutsches Zentrum Fur Luft-Und Raumfahrt E.v.

Gerhard Krieger

Christoph Schaefer

Alberto Moreira

Sigurd Huber

Nicolas Gebert

Michelangelo Villano

Marwan Younis

Josef Mittermayer

Sebastian Bertl

Jens Reimann

Patrick Klenk

Felipe Queiroz De Almeida

Francesco De Zan

Pau Prats-Iraola

Marc Rodriguez-Cassola

Thomas Kraus

Paco López-Dekker

Ulrich Steinbrecher

Mariantonietta Zonno

Francisco Lopez-Dekker

Prats-Iraola Pau

Paola Rizzoli

Muriel Aline Pinheiro

Michele Martone

Federica Bordoni

Nicola Gollin

A synthetic aperture radar method for remote sensing of the surface of the Earth by means of a radar device on a flying object moving in an azimuth direction above the surface of the Earth, wherein the radar device includes an array of antenna elements for transmitting radar pulses in a transmitting operation and for receiving radar echoes of these radar pulses reflected at the surface of the Earth in a receiving operation. A calibration mode is carried out in which

Synthetic aperture radar method and synthetic aperture radar device

The present disclosure relates to a method for computer-implemented processing of SAR raw data, which comprises radar echoes from radar pulse. An interference radar echo and an interference pulse are associated with a respective radar pulse, wherein the interference pulse and the respective radar pulse have orthogonal waveforms. SAR raw data are focused by a first focusing on the interference pulses including a range compression and an azimuth compression, to obtain first focused data, where a filtering is used for the range compression of a respective radar pulse, which filtering is matched to the waveform of the associated interference pulse. Thereafter, the first focused data undergo a signal suppression, which at least partially suppresses the interference radar echo, as a result of which second focused data are obtained. These second focused data finally undergo a defocusing including range decompression and azimuth decompression to obtain modified SAR raw data.

Method and apparatus for computer-assisted processing of SAR raw data

A reflector antenna for synthetic aperture radar, having a reflector including a reflector surface, a vertex, and an optical axis. The reflector antenna also as a plurality of antenna elements arranged side by side and in a row, for transmitting radar transmission signals and receiving radar reception signals produced from a reflection on a surface. The reflector is designed as a one-dimensional defocused reflector having two focal planes. The optical axis coincides with the line of inter-section of two imaginary planes extending at right angles to one another. The reflector has, in a first (X-) plane, a first (X-) focal plane that extends at right angles thereto and to the optical axis, and, in a second (Y-) plane, a second (Y-) focal plane which extends at right angles thereto and to the optical axis. The second (Y-) focal plane is at a greater distance from the vertex than the first (X-) focal plane.

Reflector antenna for a synthetic aperture radar

A continually adapted pulse-to-pulse shift, performed in the azimuth direction, of the phase center which is electrically active on the side of the transmitting antenna (Tx; Tx, Tx, Tx), in connection with the SAR antenna control of a multi-aperture SAR system is designed such that, in the case of an existing pulse repetition frequency (PRF) due to the likewise shifted position of the effective phase center of the entire antenna (Tx; Tx, Tx, Tx; Rx; Rx, Rx, Rx), a compensation or complete correction of non-equidistant scanning in the azimuth direction is achieved. The principle of the pulse-to-pulse shift of the position of the effective phase center of the antenna for achieving the best possible equidistant scanning can be expanded to the side of the receiving antenna (Rx; Rx, Rx, Rx) and to multi-aperture antennas. The technological solution proposed by the invention can be advantageously combined with a subsequent digital beam formation on the receiving antenna side.

Synthetic aperture radar process

The transmission antenna () of the high-resolution synthetic aperture side view radar system comprises a plurality of sub-apertures (). In each individual transmission pulse, said sub-apertures are controlled in such a manner that a spatiotemporally non-separable multi-dimensional high-frequency waveform is produced as an transmission signal pulse form, such that the modulation of each transmission pulse has a spatiotemporal diversity which is not described by the product having functions which are independent from each other and which are dependent on, respectively, only one spatial dimension. The thus produced transmission pulse form is combined to a capture-sided spatial filtering by means of digital beamforming adapted to said transmission signal pulse form.

High-resolution synthetic aperture side view radar system used by means of digital beamforming

For interferometric and/or tomographic remote sensing by means of synthetic aperture radar (SAR) one to N receiver satellites and/or transmitter satellites and/or transceiver satellites with a horizontal across-track shift the same or differing in amplitude form a configuration of satellites orbiting at the same altitude and same velocity. Furthermore, a horizontal along-track separation, constant irrespective of the orbital position, is adjustable between the individual receiver satellites. In this arrangement one or more receiver satellites orbiting at the same altitude and with the same velocity are provided with a horizontal across-track shift varying over the orbit such that the maximum of the horizontal across-track shift occurs over a different orbital position for each satellite, the maxima of the horizontal across-track shifts are positioned so that the baselines are optimized for across-track interferometry. A transmitter or transceiver satellite is positioned either separate from the configuration without across-track shift or as part of the configuration with horizontal across-track shift.

Satellite configuration for interferometric and/or tomographic remote sensing by means of synthetic aperture radar (SAR)

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Gauting, Germany

Gerhard Krieger