Spaceborne Synthetic Aperture Radar (SAR) is a unique tool for large scale Earth observation, but the current generation of SAR sensors suffers from some fundamental limitations with regard to their imaging and mapping capabilities. To overcome these limitations, several new instrument architectures and SAR imaging modes have been suggested that employ digital beamforming (DBF), multiple apertu...

The Chirp-Scaling Algorithm (CSA) is one of the most widely used synthetic aperture radar (SAR) image reconstruction method. However, its applicability is limited to straight flight trajectories and monostatic SAR. We present a new mathematical treatment of the CSA from the perspective of Fourier Integral Operators theory. Our treatment leads to a chirp-scaling-based true amplitude imaging algo...

A design constraint traceable to the early days of spacebome Synthetic Apema'e Radar (SAR) is known as the minimum antenna area constraint for SAR. In this paper, it is confirmed that this constraint strictly applies only to the case where both the best possible resolution and the widest possible swath are the design goals. SAR antennas with area smaller than the constraint allows are shown to ...

This paper presents a new Specific Absorption Rate (SAR) measurement technique that employs the ElectroOptic (EO) probe. Conventionally, the electric field (E-field) probe comprising diode-loaded dipole sensors is employed for SAR measurements. We developed a prototype of a three-axis EO probe for SAR measurement. This three-axis EO probe is capable of measuring both the amplitude and phase of ...

A new method to recognize ship target in SAR imagery using an Active Appearance Model (AAM) is proposed in this paper. The AAM can describe both shape and grey-level appearance of target which can present the SAR target more accurately.The application of AAM in SAR targets recognition was discussed in details. And the effectiveness of the method was demonstrated through the ship target classifi...

Future high resolution multi-aperture SAR satellites entail high potential for large-area traffic monitoring from space. While many approaches for detecting across-track moving vehicles in SAR images have already been published within the recent years, the detection of objects moving in along-track is still an issue to be solved. This paper deals with the detection of vehicles, mainly moving in...

Systemic acquired resistance (SAR) is an inducible immune response that depends on ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1). Here, we show that Arabidopsis (Arabidopsis thaliana) EDS1 is required for both SAR signal generation in primary infected leaves and SAR signal perception in systemic uninfected tissues. In contrast to SAR signal generation, local resistance remains intact in eds1 mutant p...