AUSGeoid98 v.1.0 data files: (sf49-04)

AUSGeoid98 data files contain a 2 minute grid of AUSGeoid98 data covering the Australian region, which you can use to interpolate geoid-ellipsoid separations for the positions required.You can use your own interpolation software, or you can use Geoscience Australia's Windows Interpolation software (Winter). The data files are text files in a standard format that cover the same area as standard topographic map areas. Files covering both 1:250,000 (approximately 100 x 150 km) and 1:1,000,000 (approximately 400 x 600 km) map areas are available. There is a 4 minute overlap on all sides of each area. Data format: AUSGeoid98 data files have a header record at the start of each file, to distinguish them from the superseded AUSGeoid93 data files. AUSGeoid98 data files show the geoid-ellipsoid separation to 3 decimal places, while the superseded AUSGeoid93 data files showed only 2 decimal places. AUSGeoid98 deflections of the vertical were computed from the geoid-ellipsoid separation surface, while the AUSGeoid93 deflections of the vertical were computed from OSU91A.

AUSGeoid98数据集文件包含覆盖澳大利亚区域的2角分分辨率数据网格，可针对所需点位插值计算大地水准面-椭球面分离量（geoid-ellipsoid separation）。用户可自行选用插值软件，亦可使用澳大利亚地球科学局开发的Windows版插值软件Winter。该数据集文件为标准格式文本文件，覆盖范围与标准地形图幅一致。现有覆盖1:25万（约100×150千米）及1:100万（约400×600千米）两种比例尺地形图幅的数据集文件。各图幅四周均存在4角分的重叠区域。数据格式：AUSGeoid98数据集文件在每个文件的起始位置均带有头部记录，用于与已被取代的AUSGeoid93数据集文件进行区分。AUSGeoid98数据集文件将大地水准面-椭球面分离量保留至小数点后三位，而已被取代的AUSGeoid93数据集文件仅保留至小数点后两位。AUSGeoid98的垂线偏差（deflections of the vertical）由大地水准面-椭球面分离曲面计算得到，而AUSGeoid93的垂线偏差则基于OSU91A重力场模型计算得出。