Bistatic Experiment Using TerraSAR-X and DLR’s new F-SAR System

A bistatic X-band experiment was successfully performed early November 2007. TerraSAR-X was used as transmitter and DLR’s new airborne radar system F-SAR, which was programmed to acquire data in a quasi-continuous mode to avoid echo window synchronization issues, was used as bistatic receiver. Precise phase and time referencing between both systems, which is essential for obtaining high resolution SAR images, was derived during the bistatic processing. Hardware setup and performance analyses of the bistatic configuration are pre-sented together with first processing results that verify the predicted synchronization and imaging performance

First Interferometric Trials with the Airborne Digital-Beamforming DBFSAR System

The Microwaves and Radar Institute of the German Aerospace Center (DLR) is known for its consistent work on the field of airborne Synthetic Aperture Radar and its application. Currently, the Institute is developing a new advanced airborne SAR system, the DBFSAR, which is planned to supplement its operational F-SAR system in near future. The development of DBFSAR was triggered by the various evolving digital beamforming (DBF) techniques for future space-borne SAR systems and the need for an airborne experimental platform for preparation of such missions. Additionally, there is a demand for very high resolution SAR imagery, which cannot anymore be fully satisfied with the existing F-SAR system. This paper should give an overview over the current status and performance of the DBFSAR system, including interferometirc results from test flights performed in spring 2017

F-SAR – DLR’s advanced airborne SAR system onboard DO228

The Microwaves and Radar Institute of the German Aerospace Center (DLR) is known for its consistent work on the field of airborne synthetic aperture radar and its application. In April 2008 we celebrate the 20th anniversary of the maiden flight of the well-known E-SAR system. E-SAR was maintained well over the time. It provided valuable knowledge to the science community, especially in the last 10 years. However, it became more and more obvious that a technological renewal was inevitable. Consequently the development of a new SAR system was put on the line some years ago under the name ‘F-SAR’. F-SAR identifies the successor of the well-known ESAR system. The system is under development at the Microwaves and Radar Institute. The development was triggered by the demand for data being simultaneously acquired at different wavelengths and polarisations as well as by the demand for very high range resolution

E-SAR Upgrade to Stepped-Frequency Mode: System Description and Data Processing Approach

A common way to enhance the range resolution of imaging radars is to adopt stepped frequency waveforms. This paper discusses in detail stepped-frequency processing possibilities on raw and processed data level, focussing on the compensation steps required to obtain high quality results. At the same time, software changes to an established SAR processor are kept at a minimum. The paper starts with a description of associated hardware extensions performed to the front-end of the E-SAR system of DLR to accommodate the stepped frequency mode in X-band. Two alternating channels, each of 100 MHz bandwidth have been implemented, which lead to a best case range resolution of 80cm corresponding to an improvement of up to 80% compared to the standard imaging mode. The performance of the complete system (including hardware and processing concept) is investigated using real data acquired with different spectral overlap between the sub-bands

F-SAR – DLR’s New Multifrequency Polarimetric Airborne SAR

F-SAR identifies the successor of the well-known E-SAR system. The system is under development at the Microwaves and Radar Institute. The development was triggered by the demand for data being simultaneously acquired at different wavelengths and polarisations as well as by the demand for very high range resolution

Usability of Long Term Evolution (LTE) in DLR’s Research Aircraft DO 228-212

In the paper the usability of LTE data transmission from an aircraft to the ground is investigated. Theoretical analyses and experimental measurements have been carried out by using a commercial low-cost LTE modem and the existing LTE base station infrastructure on ground. In the airborne experiment over wide areas a stable LTE connection was achieved

Usability of LTE for Transmitting Radar Data from DLR’s Research Aircraft DO228-212

In the paper the usability of long term evolution (LTE) data transmission from an aircraft to the ground is investigated. Theoretical analyses and experimental measurements have been carried out by using a commercial low-cost LTE modem and the existing LTE base station infrastructure on ground. No hardware modifications were made. During the experiments the aircraft was operated in altitudes of approximately 1800 and 2800 m above ground. Over wide areas a stable LTE connection was achieved

Geometric, Radiometric, Polarimetric and Along-Track Interferometric Calibration of the new F-SAR System of DLR in X-Band

Since November 2006, DLR operates F-SAR - a new airborne SAR sensor beside its experimental airborne SAR sensor E-SAR. F-SAR is a totally new development utilizing most modern hardware. It is presently operated in X-band and has been supplemented recently being fully polarimetric. F-SAR already accomplished several flights and acquired SAR data in different operation modes, amongst others in along-track-interferometric and full polarimetric mode. Several data takes were acquired at the Kaufbeuren calibration site where eleven permanently deployed corner reflectors are used for calibration. The paper describes the X-band subsystem calibration of F-SAR in geometric, radiometric and polarimetric terms and for along-track interferometry