Hydrographic survey HI634 by the RAN Australian Hydrographic Service at Davis, February 2020

The Australian Antarctic Division identified areas that required hydrographic surveying.
(See map available in the download at \Plans and Instructions\HPS Supplied Data\davis_plan_2019_2020 version 5.1.pdf and a shapefile of the identified areas at FSD\ArcGIS\Pink V2\AOI_Unproject_wgs84.shp)

A team from the Maritime Geospatial Warfare Unit, of the Australian Hydrographic Service, was at Davis in early February 2020. Single beam and side scanning survey data was collected on the water, beach profiles collected and rock data.

Single beam and side scanning survey data
Areas A, D, F, H, I, J and K were ice free.
Area J was further broken down into four areas, J1, J2, J3 and J4.
Areas A, D and F were thoroughly surveyed with 10m mainline spacing with 20m X-line spacing.
Areas I, J3 and J4 were surveyed but due to time constraints were surveyed at approximately 40m line spacing to provide 200% sea floor coverage with the SSS to detect any features dangerous to navigation with one shoal detected in area I which is mentioned in Section I.
Area H was too shallow to survey at any other time except high tide and it was decided to focus on other areas as the survey of this area would not value add to the required results of the survey.
Area J1, J2 and K were not surveyed due to time constraints.

RTK corrections or access to the CORS network couldn't be made to the CEESCOPE survey system. Instead positioning during the survey was recorded exclusively with the NovaTel GNSS 850 Antenna. No post processing was conducted. The team wasn't able to determine why the CEESCOPE was unable to connect to the CORS network or Base Station to gain RTK corrections, despite considerable effort spent problem solving and conducting a number of trials. Tide data collected was applied to the data and all tidal information is explained in section F of the report.

A map showing the surveyed areas can be found in the report.
Raw data in caris format is available from the Australian Hydrographic Office (AHO). Sounding data, stored as a shapefile, is available as a download file.

Beach profiles
Sites were also surveyed with 5m line spacing to maximise seafloor coverage, at 5 beach locations, 4 in area A and 1 in Area F. ArcGIS projects and PDF documents displaying the depth data and significant rocks are included in the download. Please note the ArcGIS projects do not include the AHO chart, due to distribution restrictions on digital charts. It is included in the PDF documents. These documents refer to images taken from the survey boat and spreadsheets displaying gradients data.

Rock data
A shapefile recording conspicuous rocks as well as photographs is available for downloading.

Bench mark positions were reclaimed using Trimble R10 and post processed with AUSPOS.

Abbreviations used in the download directories
ROS = Report of Survey,
FSD = Final Survey Data

A detailed report can be found at /ROS/

Projection……..…...…...………….….……..Universal Transverse Mercator (UTM) Zone 43 South
Horizontal Datum……………………………World Geodetic System 1984 (WGS84)
Vertical Datum…………………………….....Approximated Lowest Astronomical Tide (LAT)
Sounding Depths.……………………………Metres (m)

Survey Date………………..………………….6th - 18th Feb 2020
Bathymetric Accuracy Horizontal……………± 0.8m
Bathymetric Accuracy Vertical………………±0.46m
Sounding Density……………………………..2m Surface
Chart Reference………………………………AUS 451, 602​

ITRF 2014 and GRS80 were utilised for static observations of bench marks and levelling to the tide pole for establishment of approximate LAT. Hypack v19.1.11.0 which was used to gather all bathymetric data does not have the option to use the ITRF datum and the WGS84 Datum was used.

澳大利亚南极局确定了需要进行水文测量的区域。
(See map available in the download at Plans and InstructionsHPS Supplied Datadavis_plan_2019_2020 version 5.1.pdf and a shapefile of the identified areas at FSDArcGISPink V2AOI_Unproject_wgs84.shp)

澳大利亚水文局（Australian Hydrographic Service）下属海洋地理空间作战单元的团队于2020年2月初抵达戴维斯站。团队采集了水面单波束与侧扫测量数据、海滩剖面数据及岩石数据。

单波束与侧扫测量数据
区域A、D、F、H、I、J及K无冰覆盖。区域J进一步细分为J1、J2、J3及J4四个子区域。区域A、D、F采用10米主测线间距与20米交叉线间距进行全面测量。区域I、J3及J4虽完成测量，但受时间限制，测线间距约为40米，通过侧扫声呐（Side Scanning Sonar，SSS）实现200%的海底覆盖，以探测航行危险物；其中区域I发现一处浅滩，详见第一节（Section I）。区域H仅在高潮时可测（其余时段水深过浅），且该区域测量对达成任务目标无显著增益，故团队决定优先处理其他区域。区域J1、J2及K因时间限制未开展测量。

CEESCOPE测量系统无法获取实时动态校正（Real-Time Kinematic，RTK）或接入连续运行参考站网络（Continuously Operating Reference Station，CORS）。因此，测量期间的定位数据完全通过NovaTel GNSS 850天线记录，且未进行后处理。尽管团队投入大量精力排查问题并开展多次试验，仍无法确定CEESCOPE系统无法连接CORS网络或基站以获取RTK校正的原因。采集的潮汐数据已应用于测量数据中，所有潮汐相关信息详见报告F节（Section F）。

报告中包含显示已测区域的地图。Caris格式的原始数据可从澳大利亚水文局（Australian Hydrographic Office，AHO）获取；测深数据以形状文件（shapefile）形式存储，可通过下载文件获取。

海滩剖面
为最大化海底覆盖，团队在5处海滩（区域A4处、区域F1处）采用5米测线间距开展测量。下载文件包含展示水深数据与显著岩石的ArcGIS项目文件及PDF文档。请注意：因电子海图分发限制，ArcGIS项目文件未包含AHO海图，但该海图已嵌入PDF文档中。这些文档还参考了测量船拍摄的图像及展示坡度数据的表格。

岩石数据
记录显著岩石及相关照片的形状文件（shapefile）可供下载。

水准点位置通过天宝R10（Trimble R10）采集，并使用澳大利亚定位服务（Australian Positioning Service，AUSPOS）进行后处理。

下载目录中使用的缩写：ROS = 测量报告（Report of Survey），FSD = 最终测量数据（Final Survey Data）

投影……………………………………通用横轴墨卡托投影（Universal Transverse Mercator，UTM）南纬43区
水平基准………………………………1984世界大地坐标系（World Geodetic System 1984，WGS84）
垂直基准………………………………近似最低天文潮（Approximated Lowest Astronomical Tide，LAT）
测深单位………………………………米（m）

测量日期………………………………2020年2月6日-18日
水深测量水平精度……………………±0.8米
水深测量垂直精度……………………±0.46米
测深密度………………………………2米水面分辨率
海图参考………………………………AUS 451、602

水准点静态观测及潮汐杆水准测量（用于建立近似LAT）采用2014国际地球参考框架（International Terrestrial Reference Frame 2014，ITRF 2014）与1980大地参考系（Geodetic Reference System 1980，GRS80）。所有水深数据通过Hypack v19.1.11.0采集，但该软件不支持ITRF基准面，故采用WGS84基准面。