The ship domain is a very important and useful concept in marine traffic engineering. It has been widely used in traffic simulation models, for encounter criteria, traffic lane design criteria, VTS planning, risk assessment, collision avoidance, and for other applications.

Dr Y. Fujii, Dr E. M. Goodwin and Dr T. G. Coldwell have done a lot of work on this subject. The differences between their ship domain concepts are described in the second part of this paper. In the third part, the authors have used a new branch of social psychology – the theory of Proxemics – to analyse the factors which affect the ship domain, and point out that the basis of producing ship domains is in the field of Proxemics. Finally, in the fourth part of this paper, some problems in ship domains are analysed.

This is the concluding part of a series of three papers for this Journal, documenting the European studies into the feasibility of 1000 ft vertical separation minima above FL290. This paper outlines the results from European data collections other than the main precision radar data collection and expands upon the factors affecting height-keeping performance. The development of a Minimum Altimetry System Performance Specification (MASPS), necessary for a reduced vertical separation minimum above FL29O, is presented. A number of implementation issues, in particular monitoring, are also discussed.

The contents of this paper reflect the views of the authors; they do not necessarily reflect the official views or policy of the NLR, CAA or EUROCONTROL.

This paper is the second of a series of three papers, documenting the European studies into the feasibility of 1000 ft vertical separation minima above FL290. The paper discusses the vertical collision risk estimation methodology and an assessment of the collision risk against a target level of safety.

The analysis indicates the technical feasibility of a reduced vertical separation minima in the North Atlantic Region. However, for current operations and technical performance within European continental airspace, the risk estimation indicates that a 1000 ft minima is not technically feasible.

The contents of this paper reflect the views of the authors concerned; they do not necessarily reflect the official views or policy of the CAA or NLR.