Benchmarking CPUs and GPUs on embedded platforms for software receiver usage

Smartphones containing multi-core central processing units (CPUs) and powerful many-core graphics processing units (GPUs) bring supercomputing technology into your pocket (or into our embedded devices). This can be exploited to produce power-efficient, customized receivers with flexible correlation schemes and more advanced positioning techniques. For example, promising techniques such as the Direct Position Estimation paradigm or usage of tracking solutions based on particle filtering, seem to be very appealing in challenging environments but are likewise computationally quite demanding. This article sheds some light onto recent embedded processor developments, benchmarks Fast Fourier Transform (FFT) and correlation algorithms on representative embedded platforms and relates the results to the use in GNSS software radios. The use of embedded CPUs for signal tracking seems to be straight forward, but more research is required to fully achieve the nominal peak performance of an embedded GPU for FFT computation. Also the electrical power consumption is measured in certain load levels.Peer ReviewedPostprint (published version

Direct Digital Synthesis: A Flexible Architecture for Advanced Signals Research for Future Satellite Navigation Payloads

In legacy Global Positioning System (GPS) Satellite Navigation (SatNav) payloads, the architecture does not provide the flexibility to adapt to changing circumstances and environments. GPS SatNav payloads have largely remained unchanged since the system became fully operational in April 1995. Since then, the use of GPS has become ubiquitous in our day-to-day lives. GPS availability is now a basic assumption for distributed infrastructure; it has become inextricably tied to our national power grids, cellular networks, and global financial systems. Emerging advancements of easy to use radio technologies, such as software-defined radios (SDRs), have greatly lowered the difficulty of discovery and exploitation of vulnerabilities to these systems. The promise of a Direct Digital Synthesis (DDS) architecture provides the flexibility of incorporating countermeasures to emerging threats while maintaining backward capability with existing GPS signals. The objective of the proposed research is to determine if DDS architecture is a viable replacement for legacy GPS SatNav payloads. The overall performance of several architectures is analyzed and evaluated. The architecture with the best performance is chosen and implemented onto a programmable logic device, and GPS signals are generated. The advantages and disadvantages of using the DDS model are discussed and an end-to-end numerical and mathematical models are developed. The end-to-end mathematical model analyzes the quantization effects of the DDS architecture, and it predicts the location and power levels of the desired signal and spurious content present in the spectrum. The spurious content may potentially cause intermodulation distortion to the desired signal. The appropriate DDS architecture and resources are selected by the information gained from the mathematical model

The Digital Design and Synthesis of Delay Doppler Maps in GNSS Remote Sensing Receivers

Global Navigation Satellite Systems (GNSS) are satellite based systems primarily capable of determining the location of receivers on the Earth. However, these systems can also receive and process bistatically surface reflected signals, studying the scattering from the signal off the reflection surface. In order to achieve these results, accurate and fast technology are necessary. In this work, a Delay-Doppler mapping module of a GNSS system has been implemented in VHDL and synthesized on FPGA Xilinx-Virtex 6 to map the delay and frequency domains of Earth scattered signals. The designed system presents high timing performance to provide quick and accurate measurements. In this work, a FFT based GNSS mapping algorithms has been designed to process raw samples GNSS data. The remote sensing module has been implemented, generating all the 32 possible C/A codes and then processing the received signal for each of the 32 C/A codes in a pipelined circuit. Once the GNSS power signals have been detected, a final detector is used to compare all the GNSS power signals found with a magnitude twice the noise and with the highest peak to detect the best candidate signal for the Delay Doppler Map (DDM). Different timing delay ranges and Doppler frequency ranges have been considered to compare the performance of the mapping algorithm. The use of an FPGA based algorithm permits significantly higher performance and greater flexibility than software based solutions and opens up the GNSS remote sensing application for integration into real-time instruments

On Small Satellites for Oceanography: A Survey

The recent explosive growth of small satellite operations driven primarily from an academic or pedagogical need, has demonstrated the viability of commercial-off-the-shelf technologies in space. They have also leveraged and shown the need for development of compatible sensors primarily aimed for Earth observation tasks including monitoring terrestrial domains, communications and engineering tests. However, one domain that these platforms have not yet made substantial inroads into, is in the ocean sciences. Remote sensing has long been within the repertoire of tools for oceanographers to study dynamic large scale physical phenomena, such as gyres and fronts, bio-geochemical process transport, primary productivity and process studies in the coastal ocean. We argue that the time has come for micro and nano satellites (with mass smaller than 100 kg and 2 to 3 year development times) designed, built, tested and flown by academic departments, for coordinated observations with robotic assets in situ. We do so primarily by surveying SmallSat missions oriented towards ocean observations in the recent past, and in doing so, we update the current knowledge about what is feasible in the rapidly evolving field of platforms and sensors for this domain. We conclude by proposing a set of candidate ocean observing missions with an emphasis on radar-based observations, with a focus on Synthetic Aperture Radar.Comment: 63 pages, 4 figures, 8 table

Compass/Beidou-2 Studies: Acquisition Of Real-field Satellite Signals

With the ever-increasing interests and demands of navigation and positioning services, Global Navigation Satellite Systems (GNSS) has been drawing more and more attention. Each every country or continent is trying to establish their own GNSS system. Compass, also known as Beidou-2, which is developed by China is one of the most popular GNSS in Asian continent. Compass project was started in 2000 and until now, there has been rather few public information regarding Compass. In order to test and analyse Compass, it is necessary to obtain the existing information about Compass. In addition, acquisition and navigation are the main parts of Compass system so that to acquire the signal and extraction the navigation message in a fast and accurate way is very important. In this thesis, the Compass signals and receivers as well as three important segments of Compass systems are discussed. In addition, possible methods to achieve acquisition of Compass signals are illustrated. Meanwhile, a simulator is carried out to simulate the acquisition of Compass real-time field signals. The simulation results show that the parallel code phase search algorithm can be used to acquire Compass signals

A scalable real-time processing chain for radar exploiting illuminators of opportunity

Includes bibliographical references.This thesis details the design of a processing chain and system software for a commensal radar system, that is, a radar that makes use of illuminators of opportunity to provide the transmitted waveform. The stages of data acquisition from receiver back-end, direct path interference and clutter suppression, range/Doppler processing and target detection are described and targeted to general purpose commercial off-the-shelf computing hardware. A detailed low level design of such a processing chain for commensal radar which includes both processing stages and processing stage interactions has, to date, not been presented in the Literature. Furthermore, a novel deployment configuration for a networked multi-site FM broadcast band commensal radar system is presented in which the reference and surveillance channels are record at separate locations

Generation of a Land Cover Atlas of environmental critic zones using unconventional tools

L'abstract è presente nell'allegato / the abstract is in the attachmen

DRONE DELIVERY OF CBNRECy – DEW WEAPONS Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD)

Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD) is our sixth textbook in a series covering the world of UASs and UUVs. Our textbook takes on a whole new purview for UAS / CUAS/ UUV (drones) – how they can be used to deploy Weapons of Mass Destruction and Deception against CBRNE and civilian targets of opportunity. We are concerned with the future use of these inexpensive devices and their availability to maleficent actors. Our work suggests that UASs in air and underwater UUVs will be the future of military and civilian terrorist operations. UAS / UUVs can deliver a huge punch for a low investment and minimize human casualties.https://newprairiepress.org/ebooks/1046/thumbnail.jp

The European Satellite Navigation Program : policy analysis and recommendations for the future

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 143-148).The European Satellite Navigation Program is a case study that combines Technical / Public / Private aspects in an integrative way. Therefore, it is a sound case for a TPP thesis candidate. This thesis analyzes the European Union policies for the Galileo program, Europe's bid to have its own Global Navigation Satellite System (GNSS). Galileo is the Europe's first major attempt to develop a complex, Pan-European infrastructure project, to be owned by the European Union. It challenges its capability to gather strength and achieve the political capability to deal with major technology policy projects to lead in world affairs. It is a unique case that serves as a precedent for further infrastructure/technical projects to be managed by European Union institutions in the future. Such a major technology policy project involves the interrelation of a complex structure of multinational political and industrial organizations, and the interrelation of leading edge technical, economic, commercial and social concerns in the heart of the European Communities. During the last two decades Europe has committed to maintain a remarkable long-term vision and a strong political determination to developing Galileo. On the downside, the EU hashad difficulties in establishing a coherent financing program and a punctual manufacturer deployment. On the basis of the Galileo endeavor,this thesis assesses the use of Public Private Partnerships in large pan-European infrastructure projects in the complex political framework of the European Union. This analysis is performed upon the perspective of a theory of how to devise a strategy, a tactical plan, and a way to implement a technology policy effectively, developed by the guidelines set forth by the MIT Technology and Policy Program. It reviews the history of the European Union's policies attempting to develop Galileo, evaluates the strengths and weaknesses of such policies, and delivers a plan and a guide to help implement future projects more effectively. Finally, it aims to provide a set of recommendations for the future policymaking the European Union will face in the next decades with regard to the operation and exploitation of the system.by Laura Escudero San José.S.M.in Technology and Polic