Unlike in the case of airborne and offshore applications, GPS cannot be used continuously for land vehicle navigation due to the loss of satellite signals by obstructions from buildings, trees, etc. With the increasing trend in various sectors of the economy towards efficient fleet management, the challenges of providing a system capable of providing high-accuracy vehicle position and location anywhere, continuously, has led to renewed interest in the area of integrated navigation systems. In order to satisfy these conditions, an integrated system comprising GPS and gyro/odometer dead reckoning has been developed. This paper gives a description of the implemented system and shows some of the practical results that can be obtained using Kalman filtering algorithms.

In this study, the effect of acceleration matching according to sensor specifications in rapid transfer alignment is analysed. In general, the velocity and attitude information of the Master Inertial Navigation System (MINS) is used for transfer alignment. MINS angular velocity information is used to improve the alignment speed in shipboard transfer alignment. Acceleration matching, on the other hand, is generally considered an impractical option for transfer alignment. However, in the case of shipboard transfer alignment, acceleration matching is thought to be effective. In order to analyse the performance of acceleration matching, a performance index is defined and the efficiency of acceleration matching is analysed according to various sensor specifications and simulation environments. Based on the analysis of the estimated performance according to the simulation results, it is confirmed that acceleration matching in rapid transfer alignment is valid.

In the maritime community, a runner-up will undertake this typical process to catch up with the front runner; first, as a nation's economy grows its domestic crew costs rise, creating a gap with those abroad, which in turn depresses the international competitiveness of shipping companies. Then, to maintain their economic strength, shipping companies have their ships fly a “flag of convenience” relying on increasing amounts of cheap foreign labour. As a result, the nation gradually loses domestic seafarers, which, in the worst case, leads to a depletion of national human resource needed for its maritime cluster to continue to exist. In that sense, the personnel shortage issue is a fate for top runners in the marine transport world, where international competitiveness is inevitable. The Japanese maritime sector is just facing this issue. In this paper, the current situation in the maritime sector and its dependence on foreign labour, the cause and process of the change and the problems of the outcomes are explained, and the possible solutions in terms of the social mechanism of personnel development and utilization are discussed.

In this paper, the operability of the GMDSS is studied to identify those aspects that are hindering its successful use. Particular emphasis is placed upon the operator-equipment interface within the working environment of the ship's bridge. The results of a relevant survey, based on the opinion of recently G.O. certified navigation officers, indicate that – despite the automation in GMDSS and the resulting reduction of the human factor – there is a definite need to improve the knowledge-based proficiency of the operator. The current design of the system, and the increasing workload on the ship's bridge, constitute the main drawbacks to operability and dictate the requirement for improved knowledge and hence improved certification and refresher training for operators.

Based on the candidate architectures of the libration point satellite navigation system, a Mars navigation performance analysis is conducted in this paper to further verify the feasibility of the Universe Lighthouse. Firstly, a high-fidelity Mars exploration mission is developed as the reference scenario. Then, with the use of a novel adaptive unscented Kalman filter, navigation performance of the candidate Earth-Moon L1,2,4,5 four-satellite constellations is evaluated by Monte-Carlo simulations. The final results indicate that the libration point satellite navigation system is available for Mars navigation and the effects of different constellation configurations and measurement types are also compared and analysed.

Past research showed that traditional assessment methods that required seafarer students to construct responses based on memorisation and analysing information presented in absence of real-world contexts (e.g. oral examinations and multiple-choice questions) disengaged the students from learning. Memorising information is a lower-order cognitive ability, failure in which led to errors and low academic achievement for students. Authentic assessment methods require students to construct responses through the critical analysis of information presented in real-world contexts. Hence, this research investigated the difference in seafarer students' academic achievement (measured through scores obtained in assessment) in authentic assessment as compared with traditional assessment. Two separate and independent student groups (the ‘control’ group and ‘treatment’ group) were used for a selected unit of learning delivered at the Australian Maritime College within the Bachelor of Nautical Science degree program. Because some past researchers had defined and implemented traditional assessment methods as a single-occasion assessment, this project implemented the assessment in a summative format, as opposed to authentic assessments implemented during student preparation. Analysis of student scores revealed that the authentically assessed students were guided towards significantly higher academic achievement.

The control problem for a ship steering system with speed loss is discussed in this paper. Two methods are proposed to deal with the unknown bounded disturbance for a sliding mode controller applied to a nonlinear surface vessel heading control system. The system uncertainties caused by speed changes are taken as internal disturbances, while the wave moments are considered as external disturbances. A feedback linearization method is adopted to simplify the nonlinear system. An adaptive method and a Nonlinear Disturbance Observer (NDO) are proposed for course keeping manoeuvres and speed keeping in vessel steering and provide robust performance for time varying wave disturbance and actuator dynamics. Furthermore, the overall stability conditions of the proposed controllers are analysed by Lyapunov's direct method. Finally, simulation results using the characteristics of a naval vessel illustrate the effectiveness of the presented control algorithms.

Global Navigation Satellite System (GNSS) observations contain various errors, the separation and measurement of which is a popular research topic. Multipath effect on code measurements is investigated through the multipath combination, but carrier multipath error is small, and it is difficult to distinguish from other errors, such as hardware delay, carrier noise and satellite inherent biases. However, as the number of frequency points increases during the rapid development of GNSSs, it is possible to analyse the abovementioned errors in detail. Triple-frequency combination can be used to eliminate the first order ionospheric error, and a quad-frequency combination has one degree of freedom, which may be used to minimise carrier error effects. For this reason, an optimum method has been developed for multi-frequency GNSS code-multipath combination measurements, which has been verified by exploiting BeiDou System (BDS), three frequency data from an International GNSS Service (IGS) station and a city canyon as well as actual sampled quad-frequency data. By comparative analysis, we found that the fluctuations of an optimum triple-frequency combination are smaller than that of the non-optimum combination, which decreases the influence of inherent errors and biases on carrier phase. At the same time, second-order ionospheric error can be effectively eliminated as well. This provides a new code-multipath combination measurement optimisation methodology for future multi-frequency BDS and other GNSSs.

Galileo is a global civil navigation satellite system developed in Europe as an alternative to the GPS controlled by the US Department of Defense and GLONASS controlled by Russian Space Forces. It is scheduled to be operative in 2013 and it will have 30 satellites orbiting on three inclined planes with respect to the equatorial plane at an altitude of about 24 000 km. The aim of this work is the study of the pseudorange error of the GIOVE satellites. To achieve this goal, the specifications defined in Giove A-B Navigation Signal in Space Interface Control Document (ICD) are used to develop a suitable software tool in MATLAB® environment. The tool is able to compute GIOVE A and GIOVE B position from the broadcast ephemerides, to calculate the pseudorange error and to process it. From the known receiver position and the computed satellite coordinates, the geometric range is obtained and compared with the pseudorange measurement, in order to obtain the pseudorange error.

This paper offers an algorithm for enhancement of positioning accuracy of a quad-rotor flying robot, based on jerk and jounce of motion. The suggested method utilises the first and second numerical derivatives of the vehicle's acceleration and augments the mathematical model in the estimation process. For this purpose, the Kalman Filter (KF) is implemented for integration of a Strapdown Inertial Navigation System (SINS) and Global Navigation Satellite System (GNSS). The required data are collected from a low-cost/quality Micro Electromechanical Sensors (MEMS) during an assisted flight. For increasing the precision and accuracy of the collected data, all instruments including accelerometers, gyroscopes and magnetometers are calibrated before the experiments. Moreover, to reduce and limit the measurement noises of the MEMS sensor, a low-pass filter is applied; this is while sensors in the autopilot are affected by high levels of noise and drift, which makes them inappropriate for accurate positioning. The experimental results exhibit an improvement in positioning and altitude sensing through augmentation of the loosely coupled SINS/GNSS navigation method.

Conventional underwater navigation and positioning methods for Autonomous Underwater Vehicles (AUVs) either require the installation of acoustic arrays, which make AUVs less independent, or result in cumulative errors. This paper proposes an Underwater Terrain Positioning Method (UTPM) using Maximum a Posteriori (MAP) estimation and a Pulse Coupled Neural Network (PCNN) model for highly accurate navigation by AUVs. The PCNN model is used as a secondary discriminant to effectively identify pseudo-anchor points in flat terrain feature areas and to find the true positioning point, which significantly improves the matching positioning accuracy in these areas. Simulation results show that the proposed method effectively corrects Inertial Navigation System (INS) cumulative errors and has high matching positioning accuracy, which satisfy the requirements of AUV underwater navigation and positioning.

The Decca Navigator System was very unusual among radio-navigation systems in that the entire system was championed and marketed by a commercial company. How it came about was also unusual – it was neither the product of market research nor a military specification. It was a solution to one of the major problems of the 1930s facing those who attempted to use radio methods for the location of vehicles, that of measuring extremely small time intervals. The problem was eventually solved by pulse methods (radar), which were kept very secret at the time, but Decca offered an alternative particularly suited to marine navigation because of its use of low frequencies. No matter how good a technical solution, many systems fail if they are not actively supported by proper marketing and in this Decca Navigator was fortunate to have the backing of a major British company, the Decca Record Company. This paper describes the inception, wartime trials and eventual acceptance into general marine use of Decca Navigator. Some previously unpublished historical material from the company archives is included.

Cooperative Localisation (CL) technology is required in some situations for Multiple Unmanned Underwater Vehicle (MUUVs) missions. During the CL process, the Relative Localisation Information (RLI) of the master UUV is transmitted to slave UUVs via acoustic communication. In the underwater environment, the RLI is subject to a random time delay. Considering the time delay characteristic of the RLI during the acoustic communication, a Moving Horizon Estimation (MHE) method with a Delayed Extended Kalman Filter (DEKF)-based arrival cost update law is presented in this paper to obtain an accurate and reliable estimation of present location. Additionally, an effective computation method for the MHE method is employed, in which the “Lower Upper” (LU) factorization is used to compute the solution of the Karush-Kuhn-Tucker (KKT) system. At the end of this paper, simulation results are presented to prove the superiority and practicality of the proposed MHE algorithm.

The widespread commercial availability of location-based services depends upon every new mobile phone including positioning capability. The timescales for the introduction of these devices is far from clear, and yet the demand for high accuracy services is already increasing, particularly in the automotive and telematics sector. This paper presents a summary of the current and emerging positioning technologies, their capability, predicted timescales and their suitability for the in-car environment. Will GPS levels of accuracy be available in the mobile phone? Who are the various commercial players that may affect the ultimate choice of technology? Have new satellite services such as Galileo left it too late? The paper attempts to answer these and other questions whilst offering an insight into the convergence of satellite and cellular positioning.

This paper presents a brief overview of current human factors research into route guidance systems. A short description of different interface styles is given and a review of two road-based studies of three existing route guidance systems is provided. A general discussion then highlights a range of issues of relevance to driver-system interfaces, drawing on results both from the studies carried out, and other research. Specific aspects addressed include the content and means of presenting route guidance information, and the potential effect of interface design on driver visual behaviour and performance.

In a recent paper the author reported a distribution theory which rationalizes some fairly well established phenomena in navigational errors. Adequacy of the implied model and other existing models was investigated in the light of empirical evidence. A summary of the findings has been available in a previous issue of this Journal.

This paper provides further insights into several theoretical models, establishes formal procedures for the estimation of parameters crucial to the evaluation and design of navigational systems and investigates the potentials of a broader system of distribution models. In addition, some simplified results aiming at practical use for navigators and air traffic control authorities are provided. A real-world application of the suggested methods and theoretical results is also demonstrated.

It is now well established that homing pigeons (Columba livia) use a variety of mechanisms and cues to help them find their way home. It is far more difficult to determine the relative importance attached to such mechanisms and cues by pigeons during homing. As a step towards this quantitative stage in our understanding of homing behaviour we consider if cues contribute significantly to homing speed. In particular we attempt to assess the role of visual landmarks. Using pigeons released from familiar release sites, we demonstrate that birds home faster if they can view their surroundings from inside a Perspex box for 5 minutes prior to being released, compared to birds denied this view. Pigeons released from unfamiliar sites, however, do not show a similar improvement. We suggest that seeing familiar visual landmarks before release allows pigeons to become more certain of their current location with respect to home. Simply viewing the release site is not sufficient to produce a faster homing speed; the pigeons must be able to recognize that the release site is familiar.

Much has been written from time to time about the disaster which befell the fleet under Sir Clowdisley Shovel (or Shovell) among the rocks of the Scilly Islands on 22/23 October 1707. Although many writers have discussed the cause of the catastrophe I have come across no one who has examined the D.R. positions of the various vessels involved, and it is these which I propose to consider here.

It may be as well to recapitulate the story of the disaster. (At this time, it should be noted, the day at sea was measured from noon to noon and began twelve hours earlier than the civil day. Consequently, the afternoon at sea had a later date to that ashore. Noon positions logged were those at the end of the sea date.)

This paper describes a Multi-Criteria-Analysis (MCA)-based Decision Support System (DSS) developed for the management of incidents in maritime traffic. The developed DSS helps to organise a large quantity of information related to emergency management, spatial data and “live” data (radar data, weather forecasting data), to make it available to decision makers in a comprehensible and user-friendly way. Special care has been taken to model human Decision-Making (DM) processes during incident situations. Since the DM process is always multi-criterial, a Multi-Criteria Decision-Making (MCDM) method called Preference Ranking Organisation Method for Enrichment Evaluations (PROMETHEE) is used. However, a simplified variation of PROMETHEE II has been utilised to make results more understandable to non-expert users. The aim of this research is to incorporate effective DSS in human DM processes, thus reducing the possibility of making poor decisions. The concept of Web MCA-based DSS is presented as a case study: Web DSS developed for the east coast of the Adriatic Sea.

With the assistance provided by the white cane or guide dog, most blind pedestrians can find their way to known destinations along familiar routes. Finding new or known destinations along unfamiliar routes is more challenging. Before such a journey is attempted, detailed instructions must be acquired. The difficulty of obtaining and then reliably following such instructions deters many blind pedestrians from travelling alone in unknown areas. This paper demonstrates a technological approach, by way of field trials, that supplements the existing aids and eliminates the need for sighted guides. The approach has the potential to offer greater independence to the blind person. The investigation suggests that the methodology used in personal navigation systems for the sighted is sub-optimal for guiding the blind pedestrian. Suitable extensions are introduced, and the results show the proposed methodology is efficient for guiding the blind individual to unknown destinations in the chosen field trial environment.