GNSS ambiguity resolution with controllable failure rate for long baseline network RTK

Many large-scale GNSS CORS networks have been deployed around the world to support various commercial and scientific applications. To make use of these networks for real-time kinematic positioning services, one of the major challenges is the ambiguity resolution (AR) over long inter-station baselines in the presence of considerable atmosphere biases. Usually, the widelane ambiguities are fixed first, followed by the procedure of determination of the narrowlane ambiguity integers based on the ionosphere-free model in which the widelane integers are introduced as known quantities. This paper seeks to improve the AR performance over long baseline through efficient procedures for improved float solutions and ambiguity fixing. The contribution is threefold: (1) instead of using the ionosphere-free measurements, the absolute and/or relative ionospheric constraints are introduced in the ionosphere-constrained model to enhance the model strength, thus resulting in the better float solutions; (2) the realistic widelane ambiguity precision is estimated by capturing the multipath effects due to the observation complexity, leading to improvement of reliability of widelane AR; (3) for the narrowlane AR, the partial AR for a subset of ambiguities selected according to the successively increased elevation is applied. For fixing the scalar ambiguity, an error probability controllable rounding method is proposed. The established ionosphere-constrained model can be efficiently solved based on the sequential Kalman filter. It can be either reduced to some special models simply by adjusting the variances of ionospheric constraints, or extended with more parameters and constraints. The presented methodology is tested over seven baselines of around 100 km from USA CORS network. The results show that the new widelane AR scheme can obtain the 99.4 % successful fixing rate with 0.6 % failure rate; while the new rounding method of narrowlane AR can obtain the fix rate of 89 % with failure rate of 0.8 %. In summary, the AR reliability can be efficiently improved with rigorous controllable probability of incorrectly fixed ambiguities.

A Satellite Selection Algorithm for Achieving High Reliability of Ambiguity Resolution with GPS and Beidou Constellations

Reliability of carrier phase ambiguity resolution (AR) of an integer least-squares (ILS) problem depends on ambiguity success rate (ASR), which in practice can be well approximated by the success probability of integer bootstrapping solutions. With the current GPS constellation, sufficiently high ASR of geometry-based model can only be achievable at certain percentage of time. As a result, high reliability of AR cannot be assured by the single constellation. In the event of dual constellations system (DCS), for example, GPS and Beidou, which provide more satellites in view, users can expect significant performance benefits such as AR reliability and high precision positioning solutions. Simply using all the satellites in view for AR and positioning is a straightforward solution, but does not necessarily lead to high reliability as it is hoped. The paper presents an alternative approach that selects a subset of the visible satellites to achieve a higher reliability performance of the AR solutions in a multi-GNSS environment, instead of using all the satellites. Traditionally, satellite selection algorithms are mostly based on the position dilution of precision (PDOP) in order to meet accuracy requirements. In this contribution, some reliability criteria are introduced for GNSS satellite selection, and a novel satellite selection algorithm for reliable ambiguity resolution (SARA) is developed. The SARA algorithm allows receivers to select a subset of satellites for achieving high ASR such as above 0.99. Numerical results from a simulated dual constellation cases show that with the SARA procedure, the percentages of ASR values in excess of 0.99 and the percentages of ratio-test values passing the threshold 3 are both higher than those directly using all satellites in view, particularly in the case of dual-constellation, the percentages of ASRs (>0.99) and ratio-test values (>3) could be as high as 98.0 and 98.5 % respectively, compared to 18.1 and 25.0 % without satellite selection process. It is also worth noting that the implementation of SARA is simple and the computation time is low, which can be applied in most real-time data processing applications.

Law, ethics and pandemic preparedness : the importance of cross-jurisdictional and cross-cultural perspectives

OBJECTIVE To explore social equity, health planning, regulatory and ethical dilemmas in responding to a pandemic influenza (H5N1) outbreak, and the adequacy of protocols and standards such as the International Health Regulations (2005). APPROACH This paper analyses the role of legal and ethical considerations for pandemic preparedness, including an exploration of the relevance of cross-jurisdictional and cross-cultural perspectives in assessing the validity of goals for harmonisation of laws and policies both within and between nations. Australian and international experience is reviewed in various areas, including distribution of vaccines during a pandemic, the distribution of authority between national and local levels of government, and global and regional equity issues for poorer countries. CONCLUSION This paper finds that questions such as those of distributional justice (resource allocation) and regulatory frameworks raise important issues about the cultural and ethical acceptability of planning measures. Serious doubt is cast on a 'one size fits all' approach to international planning for managing a pandemic. It is concluded that a more nuanced approach than that contained in international guidelines may be required if an effective response is to be constructed internationally. IMPLICATIONS The paper commends the wisdom of reliance on 'soft law', international guidance that leaves plenty of room for each nation to construct its response in conformity with its own cultural and value requirements.

Editorial : Law and ethics for the bioeconomy and beyond

The convergence of biological, technological and economic realms of life has fostered the development of the bioeconomy as a new feature of contemporary society. As the meaning of life and the human body is redefined in the context of the bioeconomy, new challenges have emerged for ethics and law In the face of these challenges, it is imperative that the currency of regulatory frameworks is maintained through the processes of regular review and update. The National Health and Medical Research Council has recently released the new National Statement on Ethical Conduct in Human Research to provide guidance for health research in Australia. The new National Statement will play an important part in supporting innovation and the development of the knowledge economy.

Trade, travel and disease : the role of law in pandemic preparedness

In 2009 the world experienced an influenza pandemic caused by the H1N1 virus. While the pandemic was milder then expected, it nonetheless provided the world with an opportunity to do real-time testing of pandemic preparedness. This paper examines the threats to human health posed by infectious diseases and the challenges for the global community in development of effective surveillance systems for emerging infectious diseases. In 2005 a new revised version of the International Health Regulations (IHR) was adopted. The requirements of the IHR (2005) are outlined and considered in light of the constraints facing resource-poor countries. Finally, the paper addresses the role of domestic law-making in supporting public health preparedness and articulates a number of ethical principles that should be considered when developing new public health laws.

Pandemic preparedness in Asia : a role for law and ethics?

Management of pandemic influenza relies on complex coordination of many different dimensions of the health and social care systems, emergency services, levels of national and local government, civil society, communications and media, and cultural expectations. Law is one small but important component of those arrangements, which touch on fundamental ethical debates. This review demonstrates that the Asian region is actively engaging those issues in diverse ways in light of their varied socioeconomic and cultural backgrounds, but scope remains for prioritising further research into these relationships.

Law, ethics and pandemic preparedness : the importance of cross-jurisdictional and cross-cultural perspectives

Objective To explore social equity, health planning, regulatory and ethical dilemmas in responding to a pandemic influenza (H5N1) outbreak, and the adequacy of protocols and standards such as the International Health Regulations (2005). Approach This paper analyses the role of legal and ethical considerations for pandemic preparedness, including an exploration of the relevance of cross-jurisdictional and cross-cultural perspectives in assessing the validity of goals for harmonisation of laws and policies both within and between nations. Australian and international experience is reviewed in various areas, including distribution of vaccines during a pandemic, the distribution of authority between national and local levels of government, and global and regional equity issues for poorer countries. Conclusion This paper finds that questions such as those of distributional justice (resource allocation) and regulatory frameworks raise important issues about the cultural and ethical acceptability of planning measures. Serious doubt is cast on a ‘one size fits all’ approach to international planning for managing a pandemic. It is concluded that a more nuanced approach than that contained in international guidelines may be required if an effective response is to be constructed internationally. Implications The paper commends the wisdom of reliance on ‘soft law’, international guidance that leaves plenty of room for each nation to construct its response in conformity with its own cultural and value requirements.

Open access to infinite content (or "in praise of law reviews")

This Article is about legal scholarly publication in a time of plenitude. It is an attempt to explain why the most pressing questions in legal scholarly publishing are about how we ensure access to an infinity of content. It explains why standard assumptions about resource scarcity in publication are wrong in general, and how the changes in the modality of publication affect legal scholarship. It talks about the economics of open access to legal material, and how this connects to a future where there is infinite content. And because student-edited law reviews fit this future better than their commercially-produced, peer-refereed cousins, this Article is, in part, a defense of the crazy-beautiful institution that is the American law review.

Teaching and using analogy in law

Analogy plays a central role in legal reasoning, yet how to analogize is poorly taught and poorly practiced. We all recognize when legal analogies are being made: when a law professor suggests a difficult hypothetical in class and a student tentatively guesses at the answer based on the cases she read the night before, when an attorney advises a client to settle because a previous case goes against him, or when a judge adopts one precedent over another on the basis that it better fits the present case. However, when it comes to explaining why certain analogies are compelling, persuasive, or better than the alternative, lawyers usually draw a blank. The purpose of this article is to provide a simple model that can be used to teach and to learn how analogy actually works, and what makes one analogy superior to a competing analogy. The model is drawn from a number of theories of analogy making in cognitive science. Cognitive science is the “long-term enterprise to understand the mind scientifically.” The field studies the mechanisms that are involved in cognitive processes like thinking, memory, learning, and recall; and one of its main foci has been on how people construct analogies. The lessons from cognitive science theories of analogy can be applied to legal analogies to give students and lawyers a better understanding of this fundamental process in legal reasoning.

Health governance : law, regulation and policy

This special issue of Public Health is devoted to health governance, examining the role of law, regulation and policy in safeguarding the public's health. Each of us has devoted a career to thinking carefully about the role of law as a tool to prevent injury and disease and to promote the population's health and wellbeing. 1, 2, 3 and 4 In this Guest Editorial we first explain what we mean by the term ‘governance’, as well as the role of law in a well-regulated society. Next, we explore the increasingly important, and challenging, concept of what we call national and global federalism—the inter-relationships among the various levels of governance (local, national, supranational and transnational) and among various actors in national and global health. Third, we explain the origins of this journal symposium, which arises from three conferences on the topic in Hong Kong and Sydney. Finally, we offer a brief introduction to the articles that follow.

Health Law's Kaleidoscope : Health Law Rights in a Global Age

Within contemporary society the themes of globalization, health and regulation interlock in complex patterns, changing in response to the mix of cultural differences, regulatory preferences and available resources. To turn the kaleidoscope and to change the mix is to change the pattern. This book is about those patterns as they arise in the contemporary legal, health and ethical context, exploring the transformations and challenges brought by technological change and the regulatory options in the contemporary global village.