Europe and the USA are developing plans (‘SESAR’ and ‘NextGen’) to transform the processes of Air Traffic Management (ATM). These will improve safety and efficiency, and match predicted increases in air transportation demand. Aircraft would fly on Four Dimensional-Trajectories (4D-Trajectories), incorporating altitude, position, time, and other aircraft positions and vectors. This vision would involve extremely large investments from the airline industry and ATM service providers. Thus, development priorities need to be based on sound business cases. But will these necessarily lead to the strategic vision of a 4D-Trajectory system? Will the changes in practice be limited to a series of short and medium term operational improvements rather than strategic improvements? Killer App(lication)s is jargon for innovations so valuable that they prove the core value of some larger technology. So, are there ‘Killer Apps’ for 4D-Trajectory ATM? Killer Apps generate high degrees of stakeholder technical and financial cooperation. Ironically, most past ATM Killer Apps have improved safety. The analysis here attempts to identify and then size potential 4D-Trajectory ATM Killer Apps. The evidence for Killer Apps has to pass key tests. Killer Apps obviously have to offer enormous benefits to stakeholders in the context of the potential costs. The bulk of these benefits must not be obtainable through technologically ‘cut down’ non−4D-Trajectory versions. Part 1 of this paper sets out the framework for investigating these questions; Part 2 will be published subsequently and will examine potential Killer Apps derived from improvements in Fuel Efficiency, Capacity and Cost. An abbreviated version of this paper was first presented at the European Navigation Conference (ENC 2011), London in November 2011.

A number of automated decision support tools will be required in the future air traffic management system to enable continued provision of safe and efficient services in increasingly congested skies. In particular, Conflict Detection and Resolution (CDR) tools should allow for early detection of possible conflicts and propose safe and efficient resolution manoeuvres to avoid loss of separation. However, current approaches in the open literature not only use different levels of aircraft intent information but also make a number of assumptions on models of aircraft motion. Furthermore, information relevant to aircraft performance is often not considered with the consequence of the resulting resolution strategies being potentially unreliable. This paper presents an enhanced, strategic, pairwise, performance-based and distributed CDR algorithm. It accounts for the weaknesses of current approaches by using the maximum level of aircraft intent information together with a novel trajectory prediction model. Numerical results for representative conflict scenarios show that the proposed CDR method is able to generate conflict-free trajectories for participating aircraft while taking into account the actual aircraft capabilities to perform the recommended resolution manoeuvres.

In the process of composing a double-differenced positioning model, it is difficult to separate different frequency signals between code division multiple access (CDMA) systems, the single-difference ambiguity of the pivot satellite and phase differential inter-system biases (PDISBs). Hence it is difficult to calibrate in advance the bias between systems in order to build an inter-system model which only needs one pivot satellite. Based on analysis of the stability of PDISB parameters for non-overlapping frequency CDMA systems, this study adopts a particle filter to estimate the fractional part of the PDISBs (F-PDISBs) between the systems and proposes a particle filter-based inter-system positioning model. Results show that the F-PDISBs and code DISBs for the baselines with the same receiver types and some with different receiver types are rather stable over time and for these baselines it is feasible to use a particle filter to estimate the F-PDISB parameters in the initial stage. Having attained the F-PDISBs, the inter-system model can be constructed to improve positioning accuracy in complex operational environments.

This paper describes an algorithm for evaluation of magnetic compass deviation based on the least squares method. An automatic system was built, coupled with a magnetic compass recording device, for fine estimation of the deviation curve on the basis of an incomplete compass swing circulation.

In maritime search and rescue (SAR), commanders need to understand the task execution efficiency of each SAR unit in real time to improve the overall efficiency of SAR efforts. This study proposes a method to evaluate the progress of maritime SAR missions using automatic identification system (AIS) data. First, the positioning accuracy of the AIS data was improved according to the relationship between position, speed, and course. Second, the historical track of the SAR ship was used to generate the SAR completion area based on a line buffer algorithm. The SAR completion area and SAR mission area were then superimposed to determine the overall progress of the SAR mission. The proposed method has been deployed within the SAR software on-board Haixun01 (China's largest and most advanced large-scale cruise rescue ship) since 2017 and has played an important role in devising SAR strategies and tracking mission progress, during several SAR actions.

Recognition of obstacle type based on visual sensors is important for navigation by unmanned surface vehicles (USV), including path planning, obstacle avoidance, and reactive control. Conventional detection techniques may fail to distinguish obstacles that are similar in visual appearance in a cluttered environment. This work proposes a novel obstacle type recognition approach that combines a dilated operator with the deep-level features map of ResNet50 for autonomous navigation. First, visual images are collected and annotated from various different scenarios for USV test navigation. Second, the deep learning model, based on a dilated convolutional neural network, is set and trained. Dilated convolution allows the whole network to learn deep features with increased receptive field and further improves the performance of obstacle type recognition. Third, a series of evaluation parameters are utilised to evaluate the obtained model, such as the mean average precision (mAP), missing rate and detection speed. Finally, some experiments are designed to verify the accuracy of the proposed approach using visual images in a cluttered environment. Experimental results demonstrate that the dilated convolutional neural network obtains better recognition performance than the other methods, with an mAP of 88%.

An examination of accounts of sixteenth-century voyages shows that the estimations of latitude then arrived at by astronomical means were subject to widely varying error. The purpose of the present study has been to discover by practical experiments at sea, with replicas of instruments in use at the time, to what extent the size and irregularity of the errors can be attributed to the characteristics of the instruments and to what extent they arise from other causes. Observations were made from a 9-ton yacht under conditions not wholly dissimilar to those obtaining in some of the very small ships whose voyages are recorded.

The evidence for latitude errors is derived from published studies and from the writer's own analyses of three voyages made in northern waters by ships of the Muscovy Company: those of Stephen Borough of 1556 and 1557 and that of Arthur Pet and Charles Jackman of 1580. These were chosen because the masters in that Company's service received the best nagivational advice of the time3 and from the early 1550s onwards regularly recorded both latitude and compass variation. Furthermore, the relatively low altitude of the Sun in the higher latitudes was conducive to greater accuracy with a cross-staff.

Although numerous at smaller geographic scales, vector databases often do not exist at the more detailed, larger scales. A possible solution is the use of image processing techniques to detect edges in high-resolution satellite imagery. Features such as roads and airports are formed from the edges and matched up with similar features in existing low-resolution vector map databases. By replacing the old features with the new more accurate features, the resolution of the existing map database is improved. To accomplish this, a robust edge detection algorithm is needed that will perform well in noisy conditions. This paper studies and tests one such method, the Wavelet Multi-scale Edge Detector. The wavelet transform breaks down a signal into frequency bands at different levels. Noise present at lower scales smoothes out at higher levels. It is demonstrated that this property can be used to detect edges in noisy satellite imagery. Once edges are located, a new method will be proposed for storing these edges geographically so that features can be formed and paired with existing features in a vector map database.

For some time there has been an interest in nautical circles in the effect of temperature-differences between air and sea on the dip of the horizon. In about 1900, from his observations on board K.K.S. Pola, Koss established a relationship between the dip and the temperature-difference between air and sea, and an attempt was made, without much success, to produce corrections based on this relationship. New observations seemed only to add new uncertainties. A recent comprehensive review of the subject draws the conclusion that for practical purposes it is impossible to calculate the dip from measured temperatures by means of theoretical or empirical formulas. Indeed it is not possible to calculate the dip from simple measurements of temperatures at a given point to within o′·1 or o′·2. Horizontal irregularities, especially of thermal stratification and of wave height, always cause deviations of the dip from its calculated value. Nevertheless it is sound practice to correct the mean dip for temperature differences between air and sea. An analysis of observations where there are large temperature-differences—i.e. cases where the correction becomes noticeable—shows that the dip is greater or smaller than normal if the air is, respectively, cooler or warmer than the water. Out of 179 observations made by the Institute of Geophysics at Hamburg University with temperature-differences between air and sea greater than 2°C, not a single observation did not obey this rule.

To achieve autonomous all-day flight by high-altitude long-endurance unmanned aerial vehicle (HALE UAV), a new navigation method with deep integration of strapdown inertial measurement unit (SIMU) and triple star sensors based on atmospheric refraction correction is proposed. By analysing the atmospheric refraction model, the stellar azimuth coordinate system is introduced and the coupling relationship between attitude and position is established. Based on the geometric relationship whereby all the stellar azimuth planes intersect on the common zenith direction, the sole celestial navigation system (CNS) method by stellar refraction with triple narrow fields of view (FOVs) is studied and a loss function is built to evaluate the navigation accuracy. Finally, the new SIMU/triple star sensors deep integrated navigation method with refraction correction upgraded from the traditional inertial navigation system (INS)/CNS integrated method can be established. The results of simulations show that the proposed method can effectively restrain navigation error of a HALE UAV in 24 h steady-state cruising in the stratosphere.

This paper, which was presented at a meeting of the Institute in London on 2o May 1981, with Captain R. Maybourn in the Chair, describes some studies of the conflicts arising between a multiplicity of aircraft in straight-line flight through a volume of airspace. Topics include the effect of coercing traffic to fly fixed routes, the direction from which a threat can be expected and the choice of alerting criterion for a groundbased advisory service or an airborne collision-warning system. There are some analogies, perhaps, with marine traffic problems.

There exists, worldwide, a complex scheme for the segregation and control of various classes of air traffic. To fit into this scheme aircraft must make detours, horizontally and/or vertically, the cost of which in Europe alone must be at least £50M per annum. The cost of the rare failures in traffic management is higher still. To authors trained in electronic engineering it is therefore rather surprising that the published theory of air traffic management and control is still in a rather rudimentary form.

Piloting large vessels in increasingly congested waterways is no simple task. As in many ‘decision-making under uncertainty’ scenarios, masters, mates and pilots engaged in piloting are inundated with much information and required to make crucial decisions in real time. Piloting is also an inherently judgmental activity. Pilots and ships' captains invariably develop heuristics for transiting particular waterways. As vessels become larger, cargoes more hazardous, and the waterways more congested, decision aid technology is being considered to improve piloting decision-making. This paper describes one approach to providing improved on-board decision support to masters, mates on watch, and pilots navigating in restricted waters. We discuss (1) the use of cognitive decision aids in piloting, (2) the design of such a decision aid developed for New York harbour, (3) simulator experiments evaluating the expert system, and (4) plans to apply the approach and ‘lessons learned’ to the development of an expert system for tankers transiting the Gulf of Alaska.

This paper describes modern autopilots for ships. The development of modern optimal and adaptive control theories, together with the availability of inexpensive and fast digital computer systems, makes possible the design of more sophisticated controllers, which achieve better steering and save fuel. Autopilots which simultaneously control the yaw and roll motions are now being developed. In the near future it is to be expected that advanced track-prediction and track-keeping systems will facilitate the navigation and further contribute to fuel savings. The paper was presented at a Workshop held by the Netherlands branch of the Institute on 21 February 1986.

New navigation-related technologies and complex ships' systems are associated with a considerable amount of information and alerts on navigational bridges. Each alert triggers a process conducted by the Officer Of the Watch (OOW), which includes data collection and interpretation, decision making, as well as appropriate actions. In the case of too many alerts or poorly managed alerts, the workload of the OOW may significantly increase, and situational awareness may be compromised, increasing the risk of errors. The main goal of this research is to analyse OOW actions triggered by the alerts. The research methods included an experiment on a bridge simulator with experienced officers, a questionnaire survey and a series of interviews. The main outcomes encompass the frequency of the alerts and the number and the processing times of single actions conducted upon an alert. The results indicate that, on average, during one watch, an OOW spends 22·4 minutes conducting 64 actions triggered by 16 alerts. However, officers consider 45% of the alerts as over-prioritised and distracting at the moment of their notification.

In the design and analysis of air traffic control systems the considerations which lead to the adoption of a particular route and control structure in a given airspace are partially governed by the traffic demands between given points within the area concerned. When air traffic control plans are being developed for use in a particular area, it is of prime importance to know where the main A.T.C. problems lie and to concentrate planning effort in these parts of the system. The development of routing and control procedures should take into account the degree of risk associated with any particular route structure. In the case of near mid-air collisions (NMAC's) or collisions, quantitative prediction of the risk involved is difficult. In this paper a simple theoretical method for predicting the number of NMAC's for a particular route structure is given. Such a method has been used practically for determining the amount of control required for a particular off-airways area and to help determine the optimum control procedures for air traffic planning in that area.

In 1970 the Institute formed a Working Party to formulate views on the revision of the collision regulations. Its Interim Report is published in the Journal for October 1970 and two further contributions, by Calvert and García-Frías, were published in a subsequent number (24, 413–20). The Interim Report referred to the value that a manœuvring diagram along the lines originally proposed by Calvert and Hollingdale would have in helping the mariner to assess the effects of collision situations on alterations of course and speed. It has not been possible to secure unanimity about the form of this diagram, but the one illustrated below is based on the contributions of several members and has met with the approval of the majority of the Working Party.

Modulation design has a significant effect on the accuracy of a navigation system. Two problems exist in current modulations for Global Navigation Satellite Systems (GNSS). One is the extremely low transmission rate of navigation messages. The other is the pseudorange error caused by multipath. To solve the restrictions, a novel GNSS signal system is proposed in this paper. In the new signal system, navigation messages are modulated by Orthogonal Frequency Division Multiplexing (OFDM) modulation for high transmission rate as well as excellent anti-multipath performance and conventional ranging code is still transmitted by Phase Shift Keying-Rectangular (PSK-R) or Binary Offset Carrier (BOC) modulation for precise ranging. Both the signal components supplement each other. Simulation results show that using the proposed GNSS signal system, stable and high transmission quality along with high transmission efficiency for navigation data are achieved. Also, the anti-multipath performance is significantly improved with less computational complexity.

This study provides a global, detailed, and complete energy-saving map of strong ocean currents from the absolute geostrophic velocities calculated from satellite altimetry data, with the focus on the strong Western Boundary Currents (WBCs) in the global ocean. Theoretically, the WBCs with speeds of 2–3 knots can reduce fuel consumption by 25–50% for vessels at a sailing speed of 6 knots. The fuel savings are greater for a lower sailing speed than for a higher sailing speed. For about 1·8 million motorised fishing vessels with a lower ship speed, strong currents can evidently save fuel, time and money. Since global fishing vessels generate roughly 130 million tonnes of CO2 per annum (FAO, 2012), effective utilisation of the energy-saving map could significantly reduce CO2 emissions from ship operations.

The integration of the inertial navigation system (INS) and global navigation satellite system (GNSS) is suited for localisation and navigation applications, such as aircrafts, land vehicles and ships. The primary challenge is for navigation system to achieve accurate and reliable navigation solution during GNSS outages. This paper presents an observation prediction methodology for INS/GNSS bridging GNSS outages, which combines partial least squares regression (PLSR) and Gaussian process regression (GPR) to model the INS/GNSS observations and enable a Kalman filter to estimate INS errors. The performance of proposed PLSR/GPR prediction methodology was validated through four GNSS outages taken on flight experiment data, including diverse manoeuvre conditions. The experiment results demonstrate that remarkable performance enhancements are achieved through applying the proposed PLSR/GPR prediction methodology into INS/GNSS integration.

This paper discusses the preliminary performance analysis result of the Asia-Pacific Global Navigation Satellite Systems (GNSS) Test Bed. Currently, seven Asia-Pacific economies are participating in the Test Bed project, namely Australia, Chinese Taipei, Indonesia, Malaysia, the Philippines, Thailand and Vietnam. The Test Bed was commissioned in May 2006. The discussion topics in this paper include Test Bed system architecture and preliminary analysis of the system performance. As presented in this paper, while current Satellite-Based Augmentation System (SBAS) algorithms can improve the accuracy performance of GPS positioning results, it cannot fulfill the integrity performance required by civil aviation community. This paper analyzes the limitation of the algorithm and proposes future research topics related to the limitation.