Satellite-derived bathymetry – Mawson station, Holme Bay, 2017

1. Pre-processed satellite imagery [Mawson Station_Preprocessed_WV2_Shallow Water.tif]IMPORTANT: This data cannot be shared due to licensing conditions and is provided for archival purposes only.Worldview-2 Imagery was provided at Processing level 2A in GCS WG84. The following Pre-processing steps were applied:1.    Radiometric Correction: Digital Numbers converted to TOA Reflectance2.    Atmospheric Correction: Dark Object Subtraction3.    Masking: Masking of Land and Ice features using classification of accompanying PAN imagery4.    Shallow Water Masking: Deep water masked out by thresh-holding the green and yellow bandsThe pre-processed data is provided as an 8-band Geotiff in wg84 with pixels of 0.000018°2. Satellite-derived bathymetry grid [Mawson Station_SDB_wg84_alat.tiff]This bathymetry dataset was produced by applying the SMART-SDB model to Worldview 2 Multispectral Image acquired on 20170129 at 05:21:13Z. Singlebeam bathymetry data acquired in February 20191 using a CEESCOPE 200kHz SBES with CMAX SSS, with vertical and horizontal accuracy of 0.50m and 3.00m respectively, was used for both calibration and validation of the SMART-SDB model. Derived data was smoothed using a low pass filter, and manually cleaned for erroneous returns (however some may still exist). A description of the methods is available in the attached reports. Projection: GCS WG84Tidal datum: ALAT (approximate lowest astronomical tide) Format: geotiff, ASCI xyz Depths Derived from Satellite Imagery. For SA awareness only. Not for Navigation. Vertical Accuracy is un-assessable and should be considered worse than ZOC C. Undetected features significant to surface navigation may exist.3. Bathymetry map (Mawson Station SDB Chart_OFFICIAL.pdf)This map shows the hydrographic chart from Mawson Station overlayed with the new satellite-derived bathymetry data. 4. Python Scripts and GuideThese scripts were developed to automate extraction of satellite-derived bathymetry from the Worldview-2 imagery. Details of the scripts and how to apply them are outlined in the guide: Antarctica SDB Project How To.docx5. Final report [AASP4392_Antarctica SDB Project_FINAL_REPORT.docx]This report “Potential of Satellite-Derived Bathymetry mapping in Antarctica using high-resolution multispectral imagery” outlines the objectives, methods, results and conclusions for the satellite-derived bathymetry project (AASP4392). It has not been peer-reviewed.1 An Australian Hydrographic Service survey acquired singlebeam bathymetry data using a CEESCOPE 200kHz SBES with CMAX SSS, with vertical and horizontal accuracy of 0.50m and 3.00m respectively, in the nearshore waters of Holmes Bay near Mawson station in February 2019. This survey is part of Australian Antarctic Project (AAP) 5093: Hydrographic Surveying and Seabed Characterisation (CI: Ursula Harris)The data was extracted from the Australian Hydrographic Office database (20190208 Hydrographic survey) and is available at: O'Brien, P.E. (2011) Coastal seabed mapping survey, Vestfold Hills, Antarctica, February-March 2010, Ver. 2, Australian Antarctic Data Centre https://data.aad.gov.au/metadata/records/Davis_multibeam_grids)

1. 预处理卫星影像 [Mawson Station_Preprocessed_WV2_Shallow Water.tif]
重要提示：本数据因许可限制无法共享，仅用于存档用途。所用Worldview-2（Worldview-2）影像以2A级处理产品形式提供，采用GCS WGS84坐标系。已执行以下预处理步骤：
1. 辐射校正（Radiometric Correction）：将数字数值转换为大气顶层反射率（TOA Reflectance）
2. 大气校正（Atmospheric Correction）：采用暗目标减法（Dark Object Subtraction）
3. 掩膜处理：通过对配套全色（PAN, Panchromatic）影像进行分类，实现陆地与冰面特征掩膜
4. 浅海水域掩膜：通过对绿波段与黄波段设置阈值，掩膜去除深水区
预处理后的数据为采用WGS84坐标系的8波段GeoTIFF文件，像素分辨率为0.000018°。

2. 卫星反演水深网格 [Mawson Station_SDB_wg84_alat.tiff]
本水深数据集通过将SMART-SDB模型应用于2017年1月29日05:21:13Z获取的Worldview-2多光谱影像生成。2019年2月采集的单波束测深数据¹，使用搭载CMAX SSS的CEESCOPE 200kHz单波束测深系统（SBES, Single-beam Echo Sounder），其垂直精度与水平精度分别为0.50m与3.00m，被用于SMART-SDB模型的校准与验证。反演得到的数据经低通滤波平滑处理，并通过人工方式剔除错误回波（但仍可能存在残留错误）。相关方法说明可参见附件报告。
投影方式：GCS WGS84
潮汐基准面：ALAT（近似最低天文潮）
格式：GeoTIFF、ASCII XYZ
本数据为卫星影像反演得到的水深数据，仅用于南极海域态势感知（SA, Situational Awareness），不得用于航行导航。垂直精度无法评估，应视为低于ZOC C级。可能存在对水面航行有显著影响的未探测障碍物。

3. 测深地图（Mawson Station SDB Chart_OFFICIAL.pdf）
本地图展示了莫森站的官方水文海图，并叠加了新的卫星反演水深数据。

4. Python脚本与操作指南
本脚本用于自动化提取Worldview-2影像中的卫星反演水深数据。脚本详情与使用方法可参见操作指南《Antarctica SDB Project How To.docx》。

5. 最终报告 [AASP4392_Antarctica SDB Project_FINAL_REPORT.docx]
本报告《“南极地区高分辨率多光谱影像卫星反演水深制图潜力”》（原文标题：Potential of Satellite-Derived Bathymetry mapping in Antarctica using high-resolution multispectral imagery）阐述了AASP4392号卫星反演水深项目的目标、方法、结果与结论。本报告尚未经过同行评议。

¹ 澳大利亚水文局于2019年2月在莫森站附近霍尔姆斯湾的近岸水域，使用搭载CMAX SSS的CEESCOPE 200kHz单波束测深系统采集单波束测深数据，该系统的垂直精度与水平精度分别为0.50m与3.00m。本次测量属于澳大利亚南极项目（AAP）5093号：“海底测绘与海床特征表征”（项目负责人：Ursula Harris）。数据源自澳大利亚水文局数据库（20190208号水文测量），亦可参考：O'Brien, P.E. (2011) 南极韦斯特福尔丘陵近岸海床测绘测量，2010年2-3月，版本2，澳大利亚南极数据中心，https://data.aad.gov.au/metadata/records/Davis_multibeam_grids