This paper addresses several important aspects that need to be considered for the processing of spaceborne synthetic aperture radar (SAR) data with resolutions in decimeter range. In particular, it will shown how motion satellite during transmission/reception chirp signal and effect troposphere deteriorate impulse response function if not properly considered. Further have been investigated include curved orbit, array pattern electronically steered antennas, considerations within itself. For...

TerraSAR-X, the first civil German synthetic aperture radar (SAR) satellite, was successfully launched on June 15, 2007. After 4.5 days, processed image obtained. The overall quality of outstanding; however, suspicious features could be identified which showed precipitation-related signatures. These rain-cell signatures are thoroughly investigated, and physical background related propagation effects is provided. In addition, from former missions like SIR-C/X Shuttle Radar Topography Mission...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> TerraSAR-X is a satellite mission for scientific and commercial applications operating highly flexible X-band synthetic aperture radar (SAR) instrument with multitude of different operation modes. As product quality crucial importance, the success or failure depends essentially on method calibrating in an efficient way during commissioning entire system restricted time. Only then, correct...

Sentinel-1B is the second of two C-Band Synthetic Aperture Radar (SAR) satellites Sentinel-1 mission, launched in April 2016—two years after launch first satellite, Sentinel-1A. In addition to commissioning executed by European Space Agency (ESA), an independent system calibration was performed German Aerospace Center (DLR) on behalf ESA. Based efficient strategy and different procedures already developed applied for Sentinel-1A, extensive measurement campaigns were initializing aligning...

In the frame of COPERNICUS program, main objective Sentinel-1 mission is to ensure continuity C-band SAR data for global earth monitoring. Sentinel-1A first two satellites launched in April 2014. addition commissioning executed by European Space Agency (ESA), an independent verification system calibration has been performed DLR under ESA contract. For this purpose, complete chain was developed and established, starting with a concept, detailed in-orbit plan software tools analyzing...

Spaceborne remote sensing with synthetic aperture radar (SAR) has become an essential source of high-resolution and continuous Earth observation. Modern satellites like the German TerraSAR-X system provide state-of-the-art images respect to operating flexibility imaging quality. The outstanding performance image products is achieved by innovative calibration approach that minimizes systematic antenna instrument characteristics. active phased array X-band fed 384 transmit/receive modules for...

Modern synthetic aperture radars (SARs) are equipped with active phased array antennas to electronically generate various antenna beams. The TerraSAR-X satellite is a high resolution SAR system launched in June 2007. Its X-band hosts 384 transmit/receive modules (TRMs) for controlling the electronic beam steering azimuth and elevation direction. precise modeling of performance only possible if actual characteristics each individual TRM monitored. has been an innovative characterization mode...

TerraSAR-X is a high resolution synthetic aperture radar (SAR) satellite due for launch in 2007. Its active phased array X-Band antenna hosts 384 transmit/receive modules controlling the beam steering azimuth and elevation direction. Precise modelling of only possible if actual characteristics each individual module are known. has been equipped with an innovative characterisation mode based on so-called PN Gating method. Individual simultaneous all realised under most realistic conditions...

This paper addresses several innovative steps needed in the chirp scaling and extended (ECS) algorithms order to process staring Spotlight TerraSAR-X (TSX) images with 21 cm azimuth resolution 300 MHz range bandwidth. The aspects that need of special consideration are 2D phase truncation frequency domain ECS, element pattern antenna array, curved orbit, stop-and-go approximation, troposphere. All these expounded detail a solution is given for each them. suggested corrections applied at raw...

The high flexibility and tight accuracy requirements of modern spaceborne synthetic aperture radar (SAR) systems require innovative technologies to calibrate process SAR images. To perform accurate pattern correction during processing, an antenna model can be used derive the multitude different beams generated by active steering. application such could successfully demonstrated for TerraSAR-X mission, launched in 2007. methodology results in-orbit verification with achieved better than ±0.2...

AbstractTerraSAR-X is a high-resolution X-band synthetic aperture radar (SAR) satellite due for launch in 2006. The sensor has spatial resolution down to 1 m and operates Stripmap, Spotlight, ScanSAR modes with selectable or dual polarization. It can image on the left right side of subsatellite track, which achieved by rolling satellite. There are also experimental wide bandwidth, providing even higher resolution, full polarization along-track interferometry (ATI), latter two being splitting...

The high flexibility and tight accuracy requirements of today's spaceborne synthetic aperture radar (SAR) systems require innovative technologies to calibrate process the SAR images. To perform accurate pattern correction during processing, an Antenna Model is used derive multitude different antenna beams generated by active steering. application such could be successfully demonstrated for TerraSAR-X mission, launched in 2007. methodology results inorbit verification with achieved better...

TerraSAR-X is a satellite mission for scientific and commercial applications operating highly flexible X-band SAR instrument with multitude of different operation modes. As product quality crucial importance, the success or failure depends essentially on method calibrating in an efficient way during commissioning entire system restricted time. Only then, correct can be ensured. The paper describes final results derived from all calibration procedures.

The TanDEM-X mission based on two satellites provides a radar interferometer in space with the goal to derive global Digital Elevation Model (DEM) never achieved quality for coverage: DEM relative height accuracy of 2 m and 10 absolute. In order achieve this goal, radial cross-track distance between both satellites, so called baseline has be known high accuracy. Only then, systematic errors can detected compensated for, i.e., an accurate calibration ensured. paper describes procedure results...

The backscattering from man-made point targets like passive corner reflectors and active transponders is often used as a radiometric calibration standard for synthetic aperture radar (SAR) calibration. As new systems emerge the demand more accurate increases, it becomes necessary to better understand effects of real or imperfect on results. Therefore, point-target SAR simulator presented which models complete external process. It incorporates number target properties frequency response,...

Radiometric calibration adjusts the measured pixel intensity to a physical property, radar cross section (RCS). After calibration, this relationship is defined over entire backscatter range: from low image power (near noise) up high reflections (below saturation). Based on proper radiometric for Sentinel-1 synthetic aperture (SAR) satellite constellation validated wide range using different target types. Therefore, RCS derived point targets and brightness distributed are compared between...

SAR data products for Sentinel-1 have been freely available and delivered operationally on behalf of the European Space Agency since routine operation Sentinel-1A in 2014. These were using best knowledge at their processing time, particular with respect to radiometric calibration. As reprocessing is not foreseen nominal chain Sentinel-1, changes applied parameters impact quality can be a disturbing factor long-term monitoring features. In particular, antenna pattern updates produce...

TerraSAR-X is a satellite mission for scientific and commercial applications operating highly flexible X-band SAR instrument with multitude of different operation modes. As product quality crucial importance, the success or failure depends essentially on method calibrating in an efficient way during commissioning entire system restricted time. Only then, correct in-orbit can be ensured. The paper describes both calibration dedicated activities performed phase as well final results derived...

TerraSAR-X is a highly flexible X-band radar satellite. Its primary objective the acquisition of high quality SAR images in multitude possible modes. The great amount antenna patterns needed for image acquistion requires an model accurately describing all beams. To guarantee required quality, has to be verified on-ground and validated in-orbit. results verification will described here as well validation approach.

A synthetic aperture radar (SAR) system measures among other quantities the terrain reflectivity. After image calibration, pixel intensities are commonly expressed in terms of cross sections (RCSs) (for point targets) or as backscatter coefficients distributed targets), which directly related. This paper argues that not generally proportional to RCS derived physical quantities. further proposes replace inaccurate term by equivalent radiometric measurement quantity for SAR images. The...

A synthetic aperture radar (SAR) system requires external absolute calibration so that radiometric measurements can be exploited in numerous scientific and commercial applications. Besides estimating a factor, metrological standards also demand the derivation of respective uncertainty. This uncertainty is currently not systematically determined. Here for first time it proposed to use hierarchical modeling Bayesian statistics as consistent method handling analyzing data typically acquired...

In addition to the first satellite TSX already in-flight since 2007 [1], second TDX of TanDEM-X system could be successfully launched in 2010 [2]. The primary object mission is generate a highly accurate digital elevation model (DEM) with never achieved accuracy on global scale. But this DEM acquisition based bistatic constellation, nominal TerraSAR-X operation shall available anymore, i.e. and monostatic have operated parallel both satellites. Consequently had achieve same performance as...