Australian Hydrographic Service Surveys at Davis Station - ITRF2000

This consolidated dataset consisting of Australian Hydrographic Service (AHS) surveys HI468, HI590, HI621 and HI634 converted to International Terrestrial Reference Frame 2000 (ITRF2000) horizontal datum with Z conversion values for multiple height datums. The data was provided to the AAD by Paul Digney of Jacobs consulting in February 2021.Included survey datasets:-    HI468_Davis_Z43_Appraised_Part_ITRF2000-    HI468_Davis_Z44_Appraised_ITRF2000-    HI590_Davis_Part_ITRF2000-    HI621B_Davis_Merged_ITRF2000-    HI634_Davis_AreaA_ITRF2000-    HI634_Davis_AreaD_ITRF2000-    HI634_Davis_AreaF_ITRF2000-    HI634_Davis_AreaI_ITRF2000-    HI634_Davis_AreaJ3_ITRF2000-    HI634_Davis_AreaJ4_ITRF2000-    HI634_Davis_Rocks_ITRF2000All data are in horizontal datum ITRF2000 and have been combined into a single ESRI geodatabase feature class titled AHS_Surveys_Davis_ITRF2000.Attribute data shows quality information, conversion factors (shift in metres) for multiple datums and the MSL orthometric height in the Davis 83 datum:Column Name     Alias     MeaningEasting,     Easting,     Easting ITRF2000Northing,     Northing,     Northing ITRF2000CD_To_GRS8,     CD_To_GRS80,     LAT (Chart Datum) to the EllipsoidGRS80_To_D,     GRS80_To_DAVIS83_MSL,     Ellipsoid to DAVIS Height Datum 83Z_To_GRS80,     Z_To_GRS80,     Height to the EllipsoidZ_To_DAVIS,     Z_To_DAVIS83_MSL,     Local MSL orthometric height (DAVIS Height Datum 83)Vertical_U,     Vertical_Uncertainty,     How good is the Vertical PositionHorizontal,     Horizontal Uncertainty,     How good is the Horizontal PositionUncertaint,     Uncertainty Comments,    Depth_Comm,     Depth_Comments,    Vertical uncertainty is 0.24 to 0.5 m for hydrographic values and 0.25 to 0.5 m for terrestrial values.See the attached document ‘Metadata_Record_Davis_Final (002).xlsx’ for further details.

本整合数据集包含澳大利亚水文局（Australian Hydrographic Service, AHS）的HI468、HI590、HI621与HI634号勘测成果，已转换至国际地面参考框架2000（International Terrestrial Reference Frame 2000, ITRF2000）水平基准面，并附带多高程基准面对应的Z转换参数。该数据集于2021年2月由Jacobs咨询公司的Paul Digney提交至澳大利亚南极局（Australian Antarctic Division, AAD）。
所纳入的勘测数据集清单如下：
- HI468_Davis_Z43_Appraised_Part_ITRF2000
- HI468_Davis_Z44_Appraised_ITRF2000
- HI590_Davis_Part_ITRF2000
- HI621B_Davis_Merged_ITRF2000
- HI634_Davis_AreaA_ITRF2000
- HI634_Davis_AreaD_ITRF2000
- HI634_Davis_AreaF_ITRF2000
- HI634_Davis_AreaI_ITRF2000
- HI634_Davis_AreaJ3_ITRF2000
- HI634_Davis_AreaJ4_ITRF2000
- HI634_Davis_Rocks_ITRF2000
所有数据均采用ITRF2000水平基准面，并已整合为单个ESRI地理数据库要素类，命名为`AHS_Surveys_Davis_ITRF2000`。
属性数据包含质量信息、多基准面转换因子（米级偏移量）以及Davis 83基准面下的平均海平面正高，各属性字段详情如下：
| 列名 | 别名 | 含义说明 |
|----------------|--------------------------|--------------------------------------------------------------------------|
| Easting | Easting, | ITRF2000东向坐标 |
| Northing | Northing, | ITRF2000北向坐标 |
| CD_To_GRS8 | CD_To_GRS80, | 海图基准面至GRS80椭球面的转换参数 |
| GRS80_To_D | GRS80_To_DAVIS83_MSL | GRS80椭球面至Davis 83平均海平面高程基准面的转换参数 |
| Z_To_GRS80 | Z_To_GRS80, | 高程值至GRS80椭球面的转换参数 |
| Z_To_DAVIS | Z_To_DAVIS83_MSL, | 本地平均海平面正高（Davis 83高程基准面） |
| Vertical_U | Vertical_Uncertainty, | 垂直位置精度 |
| Horizontal | Horizontal Uncertainty, | 水平位置精度 |
| Uncertaint | Uncertainty Comments, | 精度说明注释 |
| Depth_Comm | Depth_Comments, | 测深注释 |
其中，水文测量成果的垂直精度范围为0.24~0.5米，陆地测量成果的垂直精度范围为0.25~0.5米。更多详细信息请参阅附件文档《Metadata_Record_Davis_Final (002).xlsx》。