AUSGeoid98 v.1.0 data files: (sb56-15)

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 Data format: AUSGeoid98 data files have a header record at the start of each file, to distinguish them from the superseded AUSGeoid93 data files. AUSGeoid98 data files show the geoid-ellipsoid separation to 3 decimal places, while the superseded AUSGeoid93 data files showed only 2 decimal places.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.

澳大利亚大地水准面模型1998（AUSGeoid98）数据文件包含覆盖澳大利亚区域的2分钟格网数据，可用于对所需点位的大地水准面差距（geoid-ellipsoid separations）进行插值。您可使用自行开发的插值软件，或采用澳大利亚地球科学局（Geoscience Australia）的Windows插值软件（Winter）。该数据文件为标准格式的文本文件，覆盖范围与标准地形图幅一致。可获取覆盖1:25万（约100×150千米）和1:100万（约400×600千米）两种比例尺地形图幅的数据集文件。每个图幅的四周均存在4分的重叠区域。
数据格式说明：AUSGeoid98数据文件在每个文件开头均设有文件头记录，以与已废止的澳大利亚大地水准面模型1993（AUSGeoid93）数据文件相区分。AUSGeoid98数据文件可将大地水准面差距精确至小数点后三位，而已废止的AUSGeoid93数据文件仅精确至小数点后两位。AUSGeoid98的垂线偏差（deflections of the vertical）由大地水准面差距曲面计算得到，而AUSGeoid93的垂线偏差则由俄亥俄州立大学1991A大地测量模型（OSU91A）计算得到。