AUSGeoid98 v.1.0 data files: Forrest (sh52-10)

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 Data format: AUSGeoid98 data files have a header record at the start of each file, to distinguish them from the superseded AUSGeoid93 data files. AUSGeoid98 data files show the geoid-ellipsoid separation to 3 decimal places, while the superseded AUSGeoid93 data files showed only 2 decimal places.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数据文件包含覆盖澳大利亚区域的2弧分格网数据集，可针对所需点位对大地水准面差距（geoid-ellipsoid separation）开展插值计算。用户可选用自行开发的插值软件，或使用澳大利亚地球科学局（Geoscience Australia）推出的Windows平台插值软件Winter。此类数据文件为标准格式文本文件，覆盖范围与标准地形图图幅一致。目前可获取1:25万（约100×150千米）与1:100万（约400×600千米）两种比例尺的图幅数据，各图幅的四周均预留4弧分的重叠区域。数据格式说明：每个AUSGeoid98数据文件开头均包含头记录，用于与已被取代的AUSGeoid93数据文件区分。AUSGeoid98数据文件的大地水准面差距精度保留至小数点后三位，而旧版AUSGeoid93数据文件仅保留至小数点后两位。AUSGeoid98的垂线偏差（deflections of the vertical）基于大地水准面差距曲面计算得到，而AUSGeoid93的垂线偏差则基于OSU91A模型计算得出。