AUSGeoid98 v.1.0 data files: (sj48-08)

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 Data format: AUSGeoid98 data files have a header record at the start of each file, to distinguish them from the superseded AUSGeoid93 data files. AUSGeoid98 data files show the geoid-ellipsoid separation to 3 decimal places, while the superseded AUSGeoid93 data files showed only 2 decimal places.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分钟格网AUSGeoid98数据，可针对所需点位插值求解大地水准面-椭球面分离值（geoid-ellipsoid separation）。用户可自行选用插值软件，或使用澳大利亚地球科学局（Geoscience Australia）开发的Windows版插值软件Winter。
本数据集采用标准格式的文本文件，覆盖范围与标准地形图图幅一致。现有1:250,000比例尺（约100×150千米）与1:1,000,000比例尺（约400×600千米）两类图幅的数据文件，每个图幅的各侧边均设有4分钟的重叠区域。
数据格式说明：每个AUSGeoid98数据文件的起始位置均带有头记录，用于与已被替代的AUSGeoid93数据文件区分。
AUSGeoid98数据文件可将大地水准面-椭球面分离值精确至小数点后三位，而此前的AUSGeoid93数据文件仅能精确至小数点后两位。
AUSGeoid98的垂线偏差（deflections of the vertical）基于大地水准面-椭球面分离曲面计算得到，而AUSGeoid93的垂线偏差则由OSU91A模型计算得出。