SeaMap Tasmania towed video transects 2000-2009

The SeaMap Tasmania project undertook mapping of seafloor habitats across the nearshore Tasmanian coastline (0-40 m) - the first state to compile a statewide asssimilated benthic habitat dataset.This initiative comprised of collating aerial photography (from archives), acoustic mapping, and conducting underwater video surveys and field-based visual observations. From this, 1:25,0000 scale habitat maps were created for shallow coastal water to within 1.5 km of the coastline (or 40 m depth, which ever was arrived at first).This record provided access to the raw video and associated annotations from video transects, which were subsequently used as validation (ground-truthing) for habitat mapping.A submersible digital video camera was deployed at selected locations around the Tasmanian coastline. These samples were used to verify the aerial photography and echo sounder substrate classification and obtain more detailed information on biological assemblages. Transects were undertaken from the LWM (Low water mark) to 80 metres in depth or 1.5 kms from shore. Positional information was recorded for each video drop as a series of DGPS coordinates and also as a direct overlay of the DGPS output (position, date and time) onto the video.

塔斯马尼亚SeaMap项目对塔斯马尼亚近岸海域（0-40米水深）的海底栖息地展开了测绘工作——这是首个完成全州范围整合底栖栖息地（benthic habitat）数据集的州。该举措包括整理档案中的航空摄影资料、开展声学测绘、实施水下视频调查及实地目视观测。据此，项目制作了浅海区域（距海岸线1.5公里范围内或水深40米以内，以二者中先达到的边界为准）的1:250000比例尺栖息地地图。

本记录提供了获取视频断面（video transects）原始视频及相关注释的途径，这些资料随后被用作栖息地制图的验证（实地校验）依据。

项目在塔斯马尼亚海岸线周边的选定地点部署了潜水数字摄像机。这些样本用于验证航空摄影和回声测深仪底物分类（echo sounder substrate classification）的结果，并获取生物群落（biological assemblages）的更详细信息。

断面调查从低潮线（Low water mark）延伸至水深80米处或距海岸1.5公里处。每个视频拍摄点的位置信息均以一系列差分全球定位系统（DGPS）坐标记录，并将DGPS输出的信息（位置、日期和时间）直接叠加到视频中。