Ultra-Wide Swath SAR Imaging With Continuous PRF Variation

Innovative multi-channel synthetic aperture radar (SAR) concepts enable high-resolution wide-swath imaging, but the antenna length typically restricts the achievable swath width. This limitation can be overcome by a novel technique which is based on a single azimuth channel but operates the system with a continuously varied pulse repetition frequency (PRF) by this allowing in principle for arbitrary wide swaths. This paper introduces the basic principles and discusses design constraints for such a PRF variation. Further, a systematic performance analysis of an L-band reflector antenna system is carried out with focus on the sensitivity versus different input parameters

Costs and Benefits of Quality Systems: Case Study

The variety of quality systems is a very important and an actual theme in the agri-food sector. These quality systems are only partly acknowledged by different quality standard organizations, but customers within the supply chain demand them. Enterprises, which supply different customers and export abroad this, face the problem that they have to deal with several standards and implement them within the enterprise as well as take part in several systems audits and certifications. The economic problem consists of determining the most efficient introduction of a quality system or a combination of quality systems in the enterprise. The emphasis of the work lies in the development of a framework for the benchmarking of quality systems at all stages of the agri-food production and an allocation and operationalisation of cost and benefit categories. A concept including the database “QualintSys” was developed during a PhD-thesis to estimate the costs and benefits of quality systems.Agribusiness, Agricultural and Food Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization,

Decision Support Model for the Optimization of Quality Systems in the Agri-Food Industry

Quality management is of paramount importance in all stages of the Agri-Food production and process chain. The approach of quality management has been changed in the past years due to the effects of globalization, numerous deficits in food safety and the legislative such as the new European regulation 178/2002 concerning food safeties. A trend, which can be shown, is the development of several quality systems and norms in response to this challenge. Therefore programmes will be developed and improved in the Agri-Food-industry further on. There are general quality systems, which are applied in different countries and sectors, country and product specific standards and programmes, which were developed by retail initiatives. This paper will give an insight into the variety of quality standards in the agribusiness and food industry in Europe and beyond. The main aspect will be a cost/benefit analysis for the implementation of different quality systems in firms and supply chains.quality management systems, cost, benefit, transaction costs, economic of scales, Agribusiness,

The International Quality Systems Environment

Enterprises in the agri-food sector are increasingly confronted with the need to adjust their production processes and operations to the requirements of quality systems and to integrate these requirements into their own individual integrated process management system. Integra- tion efforts are further aggravated by correlations of quality system requirements with other process related requirements. First initiatives have started to benchmark the requirements of different quality systems to have an analyse about the level of the same requirements. Output of this article will be a description of an advisory model (database model with computerized support), which presents a support tool for the implementation of quality, environ- mental and occupational health systems into the individual integrated (process) management system of enterprises. This tool includes at the moment two main parts: a benchmark of quality standards and a cost and benefit analysis approach.quality standards, benchmark, harmonisation, advisory model, Agribusiness, International Relations/Trade,

Advanced Multi-Channel SAR Imaging - Measured Data Demonstration

Synthetic Aperture Radar (SAR) is a well-established technique for remote sensing of the Earth. However, conventional SAR systems relying on only a single transmit and receive aperture are not capable of imaging a wide swath with high spatial resolution. Multi-channel SAR concepts, such as systems based on multiple receive apertures in azimuth, promise to overcome these restrictions, thus enabling high-resolution wide-swath imaging. Analysis revealed that these systems imperatively require sophisticated digital processing of the received signals in order to guarantee full performance independently of the spatial sample distribution imposed by the applied pulse repetition frequency (PRF). A suitable algorithm to cope with these challenges of multi-channel data is given by the “multi-channel reconstruction algorithm”, which demonstrated in comprehensive analysis and system design examples its potential for high perform-ance SAR imaging. In this context, various optimization strategies were investigated and aspects of operating multi-channel systems in burst modes such as ScanSAR or TOPS were discussed. Furthermore, a first proof-of-principle showed the algorithm’s applicability to measured multi-channel X-band data gathered by the German Aerospace Cen-ter’s (DLR) airborne F-SAR system. As a next step in the framework of multi-channel azimuth processing, this paper builds on the results recalled above and continues two paths. Firstly, focus is turned to further optimization of the proc-essing algorithm by investigating the classical Space-Time Adaptive Processing (STAP) applied to SAR. Secondly, attention is turned to the analysis of the measured multi-channel data by elaborating the impact and compensation of channel mismatch and by verifying the derived theory

A Large Along-Track Baseline Approach for Ground Moving Target Indication Using TanDEM-X

In the paper a new method for ground moving target indication (GMTI) using two satellites (i.e. the TerraSAR-X and the TanDEM-X satellite) together is presented. The along-track baseline between the satellites is chosen to be in the order of several kilometres, so that each satellite observes the same moving vehicles at different times in the order of one to several seconds. The proposed method allows the estimation of the ground velocity of the moving targets as well as the estimation of the broadside positions without the need of complex bistatic processing techniques

Advanced Synthetic Aperture Radar Based on Digital Beamforming and Waveform Diversity

This paper introduces innovative SAR system concepts for the acquisition of high resolution radar images with wide swath coverage from spaceborne platforms. The new concepts rely on the combination of advanced multi-channel SAR front-end architectures with novel operational modes. The architectures differ regarding their implementation complexity and it is shown that even a low number of channels is already well suited to significantly improve the imaging performance and to overcome fundamental limitations inherent to classical SAR systems. The more advanced concepts employ a multidimensional encoding of the transmitted waveforms to further improve the performance and to enable a new class of hybrid SAR imaging modes that are well suited to satisfy hitherto incompatible user requirements for frequent monitoring and detailed mapping. Implementation specific issues will be discussed and examples demonstrate the potential of the new techniques for different remote sensing applications

The IPRS Image Processing and Pattern Recognition System.

IPRS is a freely available software system which consists of about 250 library functions in C, and a set of application programs. It is designed to run under UNIX and comes with full source code, system manual pages, and a comprehensive user's and programmer's guide. It is intended for use by researchers in human vision, pattern recognition, image processing, machine vision and machine learning

On some spectral properties of TanDEM-X interferograms over forested areas

This letter reports about some obervations over rainforest (in Brazil and Indonesia), where the spectra of TanDEM-X interferograms show distinct features, almost a signature, which is explained and modelled in terms of the scattering properties. Supported by comparisons with simulations, the observations exclude any homogeneous, horizontally-layered forest; instead, they are compatible with a model with point scatterers clustered in clouds. Such a model, with high extinction and large gaps that allow significant penetration, is able to explain to a good degree the observations