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A Study of Maritime Mobile Satellite Service Requirements, Frequency Planning, Modulation and Interference Analysis. Volume I. National and International Merchant Vessel Population and Distribution: Present and Forecast

机译:海上移动卫星业务需求,频率规划,调制和干扰分析研究。第一卷国家和国际商船的人口和分布:现状和预测

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A determination was made of the population and density distribution of the world merchant fleet over the time period 1969 to 1980. The study compares various information sources for establishing the fleet population by size and vessel service category. It then examines each service category and postulates a method for distributing the ships along their trade routes. In this manner it was found that out of some 50,000 ships larger than 100 gt in 1969, approximately 21,000 were at sea. The distribution is shown on world charts. The method is compared to a more gross method where ships, regardless of service category, were tracked by their daily reported arrivals and departures for nearly two months. Historical trends and expert forecasts of ship trade in all important commodities are examined and applied to determine a forecasted merchant fleet growth and distribution, taking into account technological trends such as changes in ship size and speed. While the total number of ships is projected to grow by about 8% by 1980, improvements in efficiency show the 'at-sea' population to grow by 40%. (Author)

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