This paper studies the application of several nonlinear filters for the problem of Mars entry navigation by using radiometric measurements from Mars orbiters and Mars Surface Beacons (MSBs). A suitable dynamic model of Mars entry is developed. The movement of MSBs due to Mars rotation is also considered in the measurement model. The performance of an Extended Kalman Filter (EKF), First-order Divided Difference Filter (DDF1), Unscented Kalman Filter (UKF), and Particle Filter (PF) is compared in terms of estimation capability and computation costs. The theoretical Cramer-Rao Lower Bound (CRLB) of estimation errors are derived for Mars entry to evaluate the performance of the filters. A consistency test is also carried out to verify the filters. In simulations, by the comparison of estimation errors, position and velocity Root Mean Square Error (RMSE), error standard deviation versus Square Root of CRLB (SR CRLB), credibility and computation time, it is concluded that DDF1 is preferred for Mars entry navigation.

In December 1999, the European Commission adopted the European ‘Statement of Principles’ (SoP) in acknowledgement of the importance of the human-machine interaction (HMI) for in-vehicle telematics. In recommending adherence to the Statement of Principles, the EC urges the European motor manufacturing and supply industries to comply with a number of basic safety requirements concerning the design of, and driver interaction with, in-vehicle information, communication and entertainment systems. When the SoP was published, Member States were invited to undertake work to assess industry knowledge about, and compliance with, the Statement of Principles. TRL are currently undertaking this work for the UK Government in support of their work to assess the impact of the SoP and develop future policies concerning HMI. This paper discusses the results of a widespread UK consultation with individuals identified as working in the field of in-vehicle information, communication and entertainment systems (IVIS). It also outlines work undertaken to establish a method for assessing the extent to which a specific IVIS complies with the SoP. It describes the development and design of a HMI safety checklist that can provide an initial assessment of whether a specific IVIS is in accordance with the Principles.

This article is based on a lecture to the Royal Institute of Navigation History of Air Navigation Group at Tangmere Museum on 12 May 2004. The author served as a navigator-radar – or a radar bomb aimer – within RAF Bomber Command during the mid-1960s. This article is based on his experience of this time in Bomber Command and describes how the Medium Bomber Force would have carried out their war operations had nuclear deterrence failed. In its day these plans were TOP SECRET.

Using GPS for animal tracking applications presents many significant challenges; not least the integration of the antenna in what is usually a miniature device. This paper describes a test setup that has been constructed to allow the user to perform something close to a full antenna gain pattern test using a simple turntable and relying on the GPS satellite motion to collect all angles required for a 3D gain plot. This has proved invaluable when predicting the expected performance of various antenna/packaging options for animal tags.

There is still fierce debate in the international community regarding the use and standards of electronic chart data and equipment. Whilst the standards for ecdis are now virtually complete and type-approved equipment will be entering the market during 1998, there is currently no IMO/IHO compliant enc data service from any national hydrographic office. It is expected that it will be 1 to 2 years before there is any appreciable quantity of enc data supported by a proper update service. It will be many more years before enc data becomes available to match the present coverage of paper charts, but we can expect that most major routes and the port entries of the majority of the world's trading nations will be available within a few years. This situation is examined, together with the ideas that IMO is considering to improve the availability of official electronic chart data. In addition, the distribution of electronic charts is discussed and the future trends in navigation that will occur with the availability of ecdis equipment and related data are explored.

In an earlier study, the author attempted to give some quantitative estimates of the problems that free flow might face in Europe. The study was based on a traffic sample from the Eurocontrol Route Charges Office for a busy day in 1991. More recently, they generously made available a similar sample for a day in 1997. Using this new data, the study has been extended to cover wider aspects of the free flow problem. The central problem is that of ensuring safety. This will require a mechanism to detect collision threats and safely to resolve the problems. Possible tools are ground-based surveillance and/or airborne systems. This paper will use computer modelling to predict the loads that these detection and resolution systems must face.

This paper, and the following seven papers, were presented at the Institute's NAV94 Conference held at Church House, London, in November 1994. The full proceedings may be obtained from the Director, RIN, price £25.00 (plus p & p).

I should start by explaining that the main purpose of my paper is to pass on the Inmarsat vision of satellite navigation in the future.

But first a little about mobile satcoms, our original reason for being. If you have followed us even at a distance you will be aware of:

• (i) how we started with satcoms for ships;

• (ii) how we contributed to a new maritime safety system;

• (iii) how we developed an aeronautical satcoms system in close cooperation with the civil aviation world;

• (iv) how land-mobile communications now account for one-third of our total traffic.

It seems unfortunate that with the great advances made in modem navigation, the elementary and basic problems have been left unstandardized, incomplete and to a certain extent misleading, causing needless confusion to the student.

Pressure pattern flying embraces a number of air navigation techniques all of which have one common feature: they relate pressure distribution along an aircraft's flight path to that component of the wind which acts at right angles to the aircraft's heading. My intention is to give a brief outline of the theory underlying these techniques.

Wind is brought about by horizontal pressure differences in the earth's atmosphere. Air tends to move from an area of high pressure towards an area of low pressure under the influence of the pressure gradient force. The direction of its motion is, however, affected by the earth's rotation in space. Considering this rotation in the horizontal plane only, it is at a maximum at the poles and zero at a point on the equator. At any intermediate point of latitude ϕ, the speed of rotation in the horizontal plane is proportional to the sine of the latitude. In the northern hemisphere the rotation is anticlockwise; in the southern hemisphere it is clockwise with reference to outer space.

This paper describes the process of developing a safe access route to the Hook of Holland. The traffic situation in the Roads was tested by means of simulation. Van Riet, Pollen and Valstar are with the Directorate General of Shipping and Maritime Affairs in the Netherlands, Tresfon with the Maritime Research Institute in the Netherlands.

In a previous paper (Journal, 11, 180), the author gave assessments of the forecast wind errors likely to be met with at any point on the globe by an aircraft flying for one hour. The present paper follows this up by giving the probable errors of 24-hour wind forecasts over routes of any length, and thereby assesses the probable unpunctuality of aircraft owing to wind forecast errors.

The problem of presenting barometric height in aircraft altimeters is discussed. The alternative methods of presenting a numerical value are outlined and their characteristics analysed with reference to available comparative evidence providing a quantitative assessment. The properties of various methods of presentation are examined with reference to the varied uses of the altimeter. The conclusions are discussed with relation to the recommendations of the U.K. Altimeter Committee.

It is concluded that no single means of presenting height information will meet all of the roles in which the altimeter is used and that the recommended solution is a combination of a digital counter presentation giving an unambiguous height value combined with a circular scale and pointer rotating once per 1000 ft. providing rate and angular cue information for control purposes. Freedom of choice in presentation can only be achieved by the use of a servo-operated display.

The basic concept of case and cluster rotation in inertial navigation (IN) systems is introduced, and the reduction in the errors caused by changes in gyro and accelero-meter biases is illustrated. The general properties of cluster rotated systems are summarized and it is concluded that, although errors inside the Schuler loops may be drastically reduced by rotation, care must be taken to avoid error sources outside the loops.

A variety of different techniques has been developed for the weather routeing of sailboats. These have varied according to whether the technique is intended for yachts or for sail-assisted powered vessels, whether the routeing is for long or short time periods, and whether the routeing is used for navigation or design purposes.

The techniques that have been implemented to date are reviewed, comparing their strengths and weaknesses. Ways in which these problems may be overcome in future implementations of weather routeing are also discussed

The history of navigation and hydrography, as of other crafts or ‘mechanick arts’, has to be constructed from very imperfect materials. Instruments and charts, as the tools of practical men, were commonly discarded when they were worn out or superseded. The high mortality among original charts makes generalization in the comparative history of cartography hazardous. That no Portuguese charts before 1500 are now known does not allow us to conclude that none was made but only that none has survived. Many of the early charts that have been preserved are decorative examples drawn for royal or other patrons; those by which pilots conned their ships had a smaller expectation of life and are correspondingly rare.

The Federal Aviation Administration (FAA) is conducting experimental programmes to support introduction of satellite navigation and communications services into the air traffic control system during the 1990 time period. This work programme is closely related to the activities that have been conducted by the ICAO Future Air Navigation Systems (FANS) Committee and will result in development of standards for avionics systems and services for the Global Positioning System (GPS), as well as digital voice and digital data link services. This paper summarizes the FAA programmes supporting the introduction of the new satellite services.

In 1963, in addition to examining the characteristics of the Omega system, we were also very concerned with a comprehensive navigation system study which was designed to examine all aspects of a world-wide navigation system operating in a B.O.A.C. type environment. This concerned a study of dead reckoning as well as externally referenced sources of information. You have the choice of an all dead reckoning system probably employing multiple sensors of the same type, triple IN is typical, or you could have a mixture of externally referenced and self-contained, in other words dead reckoning sensors. Occasional reference could be made to short-range aids or even a satellite system if available to increase the integrity of the position-fixing information. The inertial and computer aspects have been examined by the Avionics Department at R.A.E. whereas the radio sensors, which are externally referenced, and the relevant software have been the responsibility of the Radio Department.

The purpose of this paper, which was presented at the seminar on Coastal Navigation described on p. 448, is to consider the role of ‘dead reckoning’ at the present time, in the context of coastal navigation, and to indicate one or two devices which might alleviate the navigator's task in trying conditions and perhaps improve the accuracy of the result.

Recent statistics are reviewed with regard to deficiencies in standards of seaworthiness often resulting in detention as noted from surveys worldwide. Recent ship loss statistics are analysed, the subject of ownership of Flag of Convenience (FOC) vessels is addressed and FOC registry related to vessel loss data. The increasing age of the world fleets is noted as replacement orders for new hulls have dwindled. Crew costs are discussed and considered in relation to economics and safety of operation. Comparison is made on ship safety between routed and non-routed vessels. Improvements in weather routeing services and safety are noted as a result of employing automated systems.

It is always reassuring to find a kindred spirit thinking along the same lines as oneself. R. Williams's proposal for a table of latitude parts (34, 247) is a reiteration of my paper of twelve years ago (23, 233).

The equations of a rhumb-line track were established by Sadler (9, 371) and it always seemed to me to be a more elegant solution to solve the equations themselves rather than to apply corrections to inaccurate equations, hence the approach suggested in my paper.