The performance of hybrid GPS and GLONASS

In recent years, the market served by satellite positioning systems has expanded exponentially. It is stimulated by the needs of an ever increasing number and variety of scientific, business and leisure applications. The dominant system is the USA's GPS, or Global Positioning System. However, GPS is not a panacea for all positioning tasks, in any environmental situation. For example, two of the fastest growing applications, vehicle tracking and personal location, operate in an often harsh signal reception environment. This can be so severe that even with the current 29 working satellites, GPS may struggle to perform. In exceptional circumstances it can fail to provide a positioning service at all. The simplest way to improve the situation when signal reception is poor, is to add similar signals from alternative satellite systems. This has already been achieved by combining GPS with the Russian satellite positioning system, Global'naya Navigatsionnaya Sputnikova Sistema, abbreviated to GLONASS. The combination of GPS with GLONASS is referred to here as Hybrid. But how good is Hybrid relative to GPS, and how can performance be evaluated objectively? The research project presented here set out to answer this question, and to understand the situations in which Hybrid failed, and ask what solutions were then available to fulfil a positioning task. The problems associated with integrating one satellite positioning system with another, their potential inconsistencies and their impact on positioning errors were also examined. This field of research is relevant to Hybrid as defined here, and also to other mixed systems, for example GPS with EGNOS, a European geostationary satellite system, and GPS with Galileo, a proposed global system controlled by the Europeans. The issues were addressed from the viewpoint of practical usage of the positioning systems. Hence the many and varied experiments to quantify positioning performance using both static receivers, and a variety of platforms with wide ranging levels of vehicle dynamics. The capability of satellite positioning systems to work in the harshest environments, was tested in the proposed Olympic sport of bob skeleton. This involved the development of the acquisition system, and a number of programs. The latter were equally applicable to the ensuing work with road vehicles, and the quantitative assessment of positioning performance relative to a truth. The processes established to manipulate, import, and merge satellite based vehicle tracking data with Ordnance Survey digital mapping products, have already been used in four other projects within the School of Civil Engineering. The software to regularise positioning interval, smoothing processes, and to compare tracking data with a truth, have been similarly provided. Without major funding the outlook for GLONASS and hence Hybrid looks bleak, and it is predicted that without replenishment the constellation may fall to six satellites by the end of 2001. However as mentioned above, the issues identified, and ideas and software developed in this research, will be directly applicable to any future hybridisation of GPS with Galileo

The performance of hybrid GPS and GLONASS

In recent years, the market served by satellite positioning systems has expanded exponentially. It is stimulated by the needs of an ever increasing number and variety of scientific, business and leisure applications. The dominant system is the USA's GPS, or Global Positioning System. However, GPS is not a panacea for all positioning tasks, in any environmental situation. For example, two of the fastest growing applications, vehicle tracking and personal location, operate in an often harsh signal reception environment. This can be so severe that even with the current 29 working satellites, GPS may struggle to perform. In exceptional circumstances it can fail to provide a positioning service at all. The simplest way to improve the situation when signal reception is poor, is to add similar signals from alternative satellite systems. This has already been achieved by combining GPS with the Russian satellite positioning system, Global'naya Navigatsionnaya Sputnikova Sistema, abbreviated to GLONASS. The combination of GPS with GLONASS is referred to here as Hybrid. But how good is Hybrid relative to GPS, and how can performance be evaluated objectively? The research project presented here set out to answer this question, and to understand the situations in which Hybrid failed, and ask what solutions were then available to fulfil a positioning task. The problems associated with integrating one satellite positioning system with another, their potential inconsistencies and their impact on positioning errors were also examined. This field of research is relevant to Hybrid as defined here, and also to other mixed systems, for example GPS with EGNOS, a European geostationary satellite system, and GPS with Galileo, a proposed global system controlled by the Europeans. The issues were addressed from the viewpoint of practical usage of the positioning systems. Hence the many and varied experiments to quantify positioning performance using both static receivers, and a variety of platforms with wide ranging levels of vehicle dynamics. The capability of satellite positioning systems to work in the harshest environments, was tested in the proposed Olympic sport of bob skeleton. This involved the development of the acquisition system, and a number of programs. The latter were equally applicable to the ensuing work with road vehicles, and the quantitative assessment of positioning performance relative to a truth. The processes established to manipulate, import, and merge satellite based vehicle tracking data with Ordnance Survey digital mapping products, have already been used in four other projects within the School of Civil Engineering. The software to regularise positioning interval, smoothing processes, and to compare tracking data with a truth, have been similarly provided. Without major funding the outlook for GLONASS and hence Hybrid looks bleak, and it is predicted that without replenishment the constellation may fall to six satellites by the end of 2001. However as mentioned above, the issues identified, and ideas and software developed in this research, will be directly applicable to any future hybridisation of GPS with Galileo

Aeronautical engineering: A continuing bibliography with indexes (supplement 260)

This bibliography lists 405 reports, articles, and other documents introduced into the NASA scientific and technical information system in December, 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

A selective list of acronyms and abbreviations

A glossary of acronyms, abbreviations, initials, code words, and phrases used at the John F. Kennedy Space Center is presented. The revision contains more than 12,100 entries

Aeronautical Engineering: A cumulative index to the 1984 issues of the continuing bibliography

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(171) through NASA SP-7037(182) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes

A cumulative index to Aeronautical Engineering: A special bibliography

This publication is a cumulative index to the abstracts contained in NASA SP-7037 (80) through NASA SP-7037 (91) of Aeronautical Engineering: A Special Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics (AIAA) and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp