关键词: GNSS; 控制网; 平面坐标; 高程; 精度分析; 海上风电工程;

Abstract: In order to survey the horizontal coordinates and elevation of the points in offshore wind farm, a GNSS control network was established.This paper mainly introduces the network design, data processing, coordinates conversion, plane coordinate and elevation measurement of offshore wind farm GNSS measurement control network, and deeply studies its network design and measurement accuracy.A set of GNSS control network layout method suitable for offshore wind farm measurement is explored, namely control network's symmetry mirror along its edge should fully cover wind farm measuring area.Through the GNSS surveying practise of Jiangsu Xiangshui offshore wind farm project, it's proved that the suggested method are feasible and its precision can meet project construction requirements.The plane coordinates accuracy can reach 3 cm, while elevation accuracy is 12 cm when the surveying point is 13 km far away from the network edge.

Key words: GNSS; control network; horizontal coordinates; elevation; precision analysis; offshore wind farm;