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Evolution of Air Traffic Management Concept of Operations and Its Impact on the System Architecture

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第4期33卷 403-413页

作者： washington Yotto ochieng Milena Studic Arnab Majumdar Center for Transport Studies Imperial College LondonSouth KensingtonLondon SW7 2AZUK College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China

The air traffic management system(ATM)has the task of ensuring safe,orderly and expeditious flow of air *** ATM system architecture is very much dependent on the concept of operations(ConOps).Over the years the evolution in ConOps has resulted in changes in the ATM′s physical architecture,improving its physical infrastructure,increasing the levels of automation and making operational changes to improve air traffic flow,to cope with increasing demand for air ***,what is less clear is the impact of such changes in ConOps on the ATM′s functional *** is vital for ensuring optimality in the implementation of the physical architecture components to support the ATM *** paper reviews the changes in the ConOps over the years,proposes a temporally invariant ATM functional model,and discusses some of the main key technologies expected to make significant improvements to the ATM system.

关键词： air traffic management concept of operations air traffic management(ATM)functions

Sector Capacity Estimation Based on Differentiated Routes and Busy Levels

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第4期34卷 438-448页

作者： Dong Xiangning Hu minghua washington Yotto ochieng College of Civil Aviation Nanjing University of Aeronautics and Astronautics Imperial College London Centre for Transport StudiesDepartment of Civil and Environmental EngineeringSouth Kensington Campus

Sector capacity estimation plays an important role in applied research of airspace *** researches manifest that sector capacity should be influenced by its standard flow,or routes in that ***,if air traffic controller(ATCO)workload busy levels(level of proactivity of an ATCO)are ignored,the estimated sector capacity may not be *** is a need to compare the estimated sector capacity with and without busy levels consideration,both with differentiated routes *** paper proposes a method for sector capacity estimation based on ATCO workload considering differentiated routes and busy ***,the main routes in the sector are identified,and for each route,the ATCO workload per flight is ***,the workload for each route at three busy levels is *** analysis is then applied to determine the relationship between workload and the number of flights(with and without considering busy levels)in 15 min and 1h time *** capacity is then determined on the basis of a specified workload threshold,for the two cases with and without considering busy *** the two scenarios and following validation by ATCO survey,it is found that capacity estimation considering busy levels is a more realistic and accurate *** validated capacity values for the Zhengzhou approach(ZHCC AP)airspace sector accounting for the busy levels were determined accurately as 10 and 33 flights for the 15 min and 1h slices,*** corresponding results without considering busy levels were 12 and 41 flights for the 15 min and 1h time slices,respectively.

关键词： ATCO workload airspace sector capacity estimation differentiated routes differentiated busy levels

New signals and systems:extending the applications of GNSS

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Geo-Spatial Information Science 2013年第3期16卷 139-140页

作者： washington Y.ochieng 不详

Over the past three decades GPS has evolved from a system designed to provide meter-level positioning for military applications to one that is used for a diverse range of unforeseen applications,for instance in engineering setting out and deformation monitoring,estimating atmospheric water vapor content,in-vehicle navigation systems,and to provide precise timing to control internet and mobile phone communications.

关键词： precise instance internet

Integration of GPS with a WiFi high accuracy ranging functionality

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Geo-Spatial Information Science 2013年第3期16卷 155-168页

作者： Khalid NUR Shaojun FENG Cong LING washington ochieng Centre for Transport Studies Department of Civil&Environmental EngineeringImperial College LondonLondonSW72AZUK Department of Electrical&Electronic Engineering Imperial College LondonLondonSW72AZUK

High accuracy seamless positioning is required to support a vast number of applications in varying operational *** the last few years,the global positioning system(GPS)has become the de facto technology for positioning ***,its performance is limited in indoor and dense urban environments due to multipath as well as signal attenuation and blockage.A number of techniques integrating GPS with other positioning technologies have been developed to address the limitations of standalone GPS in these difficult *** most of the developed techniques cover the outages of GPS in such environments,they do not provide acceptable performance,in terms of positioning accuracy,especially for some mission-critical(***)*** paper proposes a tightly coupled(*** the measurement domain)GPS/WiFi integration method which,in addition to addressing GPS outages,improves the overall positioning accuracy to the meter-level,thus satisfying the requirements of a number of location based services and intelligent transport systems *** performance of the proposed GPS/WiFi integration method is assessed for a number of scenarios in a simulation environment for an identified dense urban area in London,UK.

关键词： GPS integration time estimation WiFi Improved FOCUSS for Arrival Time Estimation(IFATE) Time Difference of Arrival(TDOA) WLAN IEEE802.11g

New methods for dual constellation single receiver positioning and integrity monitoring

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Geo-Spatial Information Science 2013年第3期16卷 201-209页

作者： Shaojun FENG Altti JOKINEN Carl MILNER washington ochieng Centre for Transport Studies Department of Civil&Environmental EngineeringImperial College LondonLondon SW72AZUK Département Sciences et Ingénierie de la Navigation Aériene(SINA) Ecole Nationale de l'Aviation Civile(ENAC)ToulouseFrance

Navigation system integrity monitoring is crucial for mission(***)critical *** autonomous integrity monitoring(RAIM)based on consistency checking of redundant measurements is widely used for many ***,there are many challenges to the use of RAIM associated with multiple constellations and applications with very stringent *** paper discusses two positioning techniques and corresponding integrity monitoring *** first is the use of single frequency pseudorange-based dual *** employs a new cross constellation single difference scheme to benefit from the similarities while addressing the differences between the *** second technique uses dual frequency carrier phase measurements from GLONASS and the global positioning system for precise point *** results show significant improvements both in positioning accuracy and integrity monitoring as a result of the use of two *** dual constellation positioning and integrity monitoring algorithms have the potential to be extended to multiple constellations.

关键词： receiver autonomous integrity monitoring(RAIM) ambiguity validation multiple constellations precise point positioning(PPP)

Integrity monitoring of fixed ambiguity Precise Point Positioning(PPP)solutions

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Geo-Spatial Information Science 2013年第3期16卷 141-148页

作者： Altti JOKINEN Shaojun FENG Wolfgang SCHUSTER washington ochieng Chris HIDE Terry MOORE Chris HILL Department of Civil and Environmental Engineering Imperial College London Centre for Transport StudiesLondon SW72AZUK Nottingham Geospatial Institute(NGI) University of NottinghamNottingham NG72TUUK

Traditional positioning methods,such as conventional Real Time Kinematic(cRTK)rely upon local reference networks to enable users to achieve high-accuracy *** need for such relatively dense networks has significant cost *** Point Positioning(PPP)on the other hand is a positioning method capable of centimeter-level positioning without the need for such local networks,hence providing significant cost benefits especially in remote *** paper presents the state-of-the-art PPP method using both GPS and GLONASS measurements to estimate the float position solution before attempting to resolve GPS integer *** monitoring is carried out using the Imperial College Carrier-phase Receiver Autonomous Integrity Monitoring method.A new method to detect and exclude GPS base-satellite failures is developed.A base-satellite is a satellite whose measurements are differenced from other satellite’s measurements when using between-satellite-differenced measurements to estimate *** failure detection and exclusion methods are tested using static GNSS data recorded by International GNSS Service stations both in static and dynamic processing *** results show that failure detection can be achieved in all cases tested and failure exclusion can be achieved for static *** the kinematic processing cases,failure exclusion is more difficult because the higher noise in the measurement residuals increases the difficulty to distinguish between failures associated with the base-satellite and other satellites.

关键词： Precise Point Positioning(PPP) integrity ambiguity resolution failure exclusion

Machine learning based GNSS signal classifcation and weighting scheme design in the built environment:a comparative experiment

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Satellite Navigation 2023年第1期4卷 54-76,I0003页

作者： Lintong Li Mireille Elhajj Yuxiang Feng washington Yotto ochieng Department of Civil and Environmental Engineering Imperial College LondonLondonUK Astra-Terra Limited LondonUK

None-Line-of-Sight(NLOS)signals denote Global Navigation Satellite System(GNSS)signals received indirectly from satellites and could result in unacceptable positioning *** meet the high mission-critical transportation and logistics demand,NLOS signals received in the built environment should be detected,corrected,and *** paper proposes a cost-efective NLOS impact mitigation approach using only GNSS *** exploiting more signal Quality Indicators(QIs),such as the standard deviation of pseudorange,Carrier-to-Noise Ratio(C/N0),elevation and azimuth angle,this paper compares machine-learning-based classifcation algorithms to detect and exclude NLOS signals in the pre-processing *** probability of the presence of NLOS is predicted using regression *** a pre-defned threshold,the signals can be classifed as Line-of-Sight(LOS)or *** probability of the occurrence of NLOS is also used for signal subset selection and specifcation of a novel weighting *** novel weighting scheme consists of both C/N0 and elevation angle and NLOS *** results show that the best LOS/NLOS classifcation algorithm is the random *** best QI set for NLOS classifcation is the frst three QIs mentioned above and the diference of azimuth *** classifcation accuracy obtained from this proposed algorithm can reach 93.430%,with 2.810%false *** proposed signal classifer and weighting scheme improved the positioning accuracy by 69.000%and 40.700%in the horizontal direction,79.361%and 75.322%in the vertical direction,and 75.963%and 67.824%in the 3D direction.

关键词： GNSS NLOS FDE Decision tree Weighting scheme

Effect of Working Experience on Air Traffic Controller Eye Movement

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Engineering 2021年第4期7卷 488-494页

作者： Yanjun Wang Liwei Wang Siyuan Lin Wei Cong Jianfei Xue washington ochieng College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 210016China AVIC ATM System and Equipment Co. LtdShanghai 200241China VariFlight Company Hefei 230061China Department of Computer Science Brandeis UniversityWalthamMA 02453USA Center for Transport Studies Imperial College LondonLondon SW72BUUK

Eye movement is an important indicator of information-seeking behavior and provides insight into cognitive strategies which are vital for *** measures based on eye movements have been proposed to capture humans’ability to process information in a complex *** effectiveness of these measures has not yet been fully explored in the field of air traffic *** paper presents a comparative study on eye-movement measures in air traffic controllers with different levels of working *** commonly investigated oculomotor behaviors,fixation and saccades,together with gaze entropy,are *** comparing the statistical properties of the relevant metrics,it is shown that working experience has a notable effect on eye-movement *** fixation and saccades differ between qualified and novice controllers,with the former type of controller employing more efficient searching *** findings are useful in enhancing the quality of controller training and contributing to an understanding of the information-seeking mechanisms humans use when executing complex tasks.

关键词： Air traffic control Human factors Eye movements Working experience

Integer Ambiguity Validation in GNSS Positioning

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Integer Ambiguity Validation in GNSS Positioning