Australian Bathymetry and Topography Grid, June 2009

In 2005 Geoscience Australia and the National Oceans Office undertook a joint project to produce a consistent, high-quality 9 arc second (0.0025° or ~250m at the equator) bathymetric grid for Australian waters. In 2009 a number of new datasets were included in an updated version of the grid.

The 2009 bathymetric grid of Australia has been produced to include recently acquired datasets, and solutions to issues identified in the previous version. The revised grid has the same extents as its 2005 counterpart, including the Australian water column jurisdiction lying between 92° E and 172° E, and 8° S and 60° S. The waters adjacent to the continent of Australia and Tasmania are included, as are areas surrounding Macquarie Island, and the Australian Territories of Norfolk Island, Christmas Island, and Cocos (Keeling) Islands. The area selected does not include Australia's marine jurisdiction offshore from the Territory of Heard and McDonald Islands and the Australian Antarctic Territory.

This report details the datasets and procedures used to produce the 2009 bathymetric grid of Australia. As per the 2005 grid, the 0.0025 decimal degree (dd) resolution is only supported where direct bathymetric observations are sufficiently dense (e.g. where swath bathymetry data or digitised chart data exist) (Webster and Petkovic, 2005). In areas where no sounding data are available (in waters off the Australian shelf), the grid is based on the 2 arc minute ETOPO (Smith and Sandwell, 1997) and 1 arc minute ETOPO (Amante and Eakins, 2008) satellite derived bathymetry. The topographic data (on shore data) is based on the revised Australian 0.0025dd topography grid (Geoscience Australia, 2008), the 0.0025dd NZ topography grid (Geographx, 2008) and the 90m SRTM DEM (Jarvis et al, 2008).

The final dataset has been provided in ESRI grid and ER Mapper (ers) formats. An associated shapefile has been produced so that the user can identify the input datasets that were used in the final grid.

IMPORTANT INFORMATION

This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service. Geoscience Australia produces the 0.0025dd bathymetric grid of Australia specifically to provide regional and local broad scale context for scientific and industry projects, and public education.

The 0.0025dd grid size is, in many regions of this grid, far in excess of the optimal grid size for some of the input data used. On parts of the continental shelf it may be possible to produce grids at higher resolution, especially where LADS or multibeam surveys exist. However these surveys typically only cover small areas and hence do not warrant the production a regional scale grid at less than 0.0025dd.

There are a number of bathymetric datasets that have not been included in this grid for various reasons. Comments or queries about the data included in the grid (or excluded) can be directed to: [e-mail].

This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service.

2005年，澳大利亚地质调查局（Geoscience Australia）与国家海洋局（National Oceans Office）联合开展项目，旨在为澳大利亚海域构建一套统一规范、高质量的9弧秒（0.0025°，赤道处约250米）水深栅格数据集。2009年，该栅格的更新版本纳入了一批全新获取的数据集。

2009年版澳大利亚水深栅格整合了最新采集的数据集，并修复了前一版本中发现的各类问题。修订后的栅格与2005年版具有完全一致的覆盖范围，涵盖东经92°至172°、南纬8°至60°的澳大利亚管辖海域，包括澳大利亚本土与塔斯马尼亚岛周边水域、麦夸里岛周边海域，以及诺福克岛、圣诞岛和科科斯（基林）群岛等澳大利亚海外领地海域。本次选取的覆盖范围未包含赫德岛和麦克唐纳群岛领地以及澳大利亚南极领地的近海管辖水域。

本报告详细介绍了用于构建2009年版澳大利亚水深栅格的数据集与处理流程。与2005年版一致，仅在直接水深观测数据足够密集的区域（例如存在条带测深数据或数字化海图数据的区域），才支持采用0.0025十进制度（dd）的分辨率（Webster与Petkovic，2005）。在无测深数据的澳大利亚陆架外海域，本栅格基于2弧分ETOPO（Smith与Sandwell，1997）和1弧分ETOPO（Amante与Eakins，2008）的卫星衍生水深数据构建。陆上地形数据则基于修订后的澳大利亚0.0025dd地形栅格（澳大利亚地质调查局，2008）、新西兰0.0025dd地形栅格（Geographx，2008）以及90米分辨率SRTM数字高程模型（DEM，Jarvis等，2008）。

最终数据集以ESRI栅格和ER Mapper（ers）格式提供。同时配套生成了一个形状文件（shapefile），以便用户识别用于构建最终栅格的各类输入数据集。

### 重要说明
本栅格不适用于航海导航辅助用途，亦不得替代澳大利亚水文服务局（Australian Hydrographic Service）生产的任何官方产品。澳大利亚地质调查局开发0.0025dd版澳大利亚水深栅格，旨在为科学研究与产业项目提供区域及局域的宏观背景支撑，并服务于公众科普教育。
本栅格的0.0025dd分辨率在诸多区域远超部分输入数据的最优栅格尺度。在部分大陆架区域，可针对存在机载激光测深系统（LADS）或多波束测量数据的区域生成更高分辨率的栅格，但此类测量作业通常仅覆盖小范围区域，不足以支撑构建分辨率高于0.0025dd的区域性栅格。
本栅格因各类原因未纳入若干水深数据集。若对栅格中纳入（或未纳入）的数据存在意见或疑问，请联系：[e-mail]。
本栅格不适用于航海导航辅助用途，亦不得替代澳大利亚水文服务局生产的任何官方产品。