Abstract :
The Niton and Cullercoats stations are the first to be equipped by the G.P.O. for a regular direction-finding service. The apparatus, which is of the well-known Bellini-Tosi pattern, is briefly described and the methods employed in taking a bearing are discussed. The satisfactory installation of the apparatus is followed by a calibration in co-operation with a ship. Experience shows that this is absolutely necessary, owing to errors introduced by objects in the vicinity of the station. The method is described in detail, and the error curves obtained are analysed with reference to the local conditions. The influence of neighbouring bodies on the error curve is investigated, and it is shown that the deviations obtained may be expected to remain constant. Experience indicates that this is true, so that a station which at first sight appears to be poorly situated may be capable of providing a reliable service if suitable precautions are observed.
