This paper formed the 1988 Anderson Memorial Lecture, and was presented to the Boscombe Down Branch on 17 March.

Wing Commander Anderson, in addition to his many distinctions connected with our Institute (a Founder Member, President, Gold Medallist, Honorary Member and frequent office holder) was above all an indefatigable worker for the science and artistry of navigation, which he regarded as a basic activity of all mankind. In 1939 he was headmaster of a school and by 1945 had become one of the most outstanding operational navigators in the Royal Air Force. In that year he was chosen as navigator of the research aircraft, Aries I, for those epic flights over the North geographic and magnetic poles, investigating compass performance in high latitudes.

The magnetic field of the Earth originates in the motions of the fluid core of the planet. By good fortune it is predominantly dipolar and so has a simple topography. The core motions cause the field to change with time, and once charted it has to be charted again and again. Mathematical models can be made which represent the geomagnetic field to an accuracy of about one degree globally. Higher accuracy demands advanced techniques such as satellite surveys, and also attention to the detail of external fields caused by solar activity which disturb the main field, restricting the accuracy of mapping and producing magnetic deviations from the mean value from day to day. Understanding such effects is essential in preparing magnetic reference data for navigation.

Though now losing ground to other methods, magnetic compasses still have a valuable role to play in many situations, so long as the limitations are fully appreciated and taken into account. Modern technology in standard geomagnetic observatories offers ways of updating a datum very accurately in automatic navigational systems and even of forecasting disturbances, and may bring magnetic reference back to the forefront of many navigational systems.

The chief failing of surface astronavigation in its traditional form is reliability – it needs clear skies! Any solution to this limitation must therefore centre on a more weather-independent means of both detecting and identifying astronomical objects. This implies that the detection process should be conducted not in the optical but in the radio waveband, although radio astronomy makes it clear that the rather simple distribution and ‘point’-like images seen visually do not exist at radio wavelengths.

This paper is the first of a series on Air Navigation Systems during the fifty years from the early oceanic flights and the inception of commercial aviation to the introduction of INS in civil aircraft. These papers are intended as critical commentaries. A definitive history has yet to be written. The writer would be grateful to receive criticisms of the paper or comments on the subject.

The Institute’s NAV 88 Conference, with the above title, was held in London from 22 to 24 March. It included nearly 40 papers concerned broadly with the way ahead for radionavigation in Europe. The Jull proceedings of the Conference are available on application to the Director, price £30 (plus £3 p & p) for Members (£60 plus p & p for non-Members). A summary of the Conference is presented below, and this is followed by one of the Conference papers which describes a rationalization of radionavigation in the USA.

This briefing presents an overview of one section of a recently enacted Statute (US Public Law 100–223 signed into Law by the President of the United States on 30 December 1987) which directs the US Secretary of Transportation to effect certain improvements in US-provided radio navigation systems.

Weather-related ship loss statistics are assessed as a proportion of total losses to ascertain the requirement for route planning. A routeing assessment for suitability of on-board application is undertaken and a moveable grid is then proposed incorporating a time optimization procedure for the on-board system.