Missouri River bed elevations near Omaha Public Power District transmission tower surveyed during 2011 flood on June, 21

A RESON SeaBat™ 7125 multibeam echosounder in conjunction with an Applanix Position Orientation Solution for Marine Vessels (POS MV™) WaveMaster system motion sensor, HYPACK®/HYSWEEP® navigation software, and Ashtech Z-Xtreme GPS receivers or Trimble R8 receivers was used to survey the Missouri River bed at 15 pipeline crossings at four different locations, at three power plant locations, and at one transmission tower during the 2011 flood event. The format of this data is a grid with each cell covering 0.5 meter by 0.5 meter. The elevation value (North American Vertical Datum, NAVD88) represented by each cell is the most probable elevation for that cell based on calculated Total Propagated Uncertainty (TPU) as calculated in Caris HIPS and SIPS software. Calculated TPS values are then used by Caris to create a Combined Uncertainty and Bathymetric Estimator (CUBE) surface. The surface grid was used to export the cell centroid position (Northing, Easting in UTM zone 14 North, in meters) along with the cell elevation (referenced to NAVD88, in meters) to create the text file. The data were collected by the U.S. Geological Survey in cooperation with the Environmental Protection Agency (EPA) and the Omaha Public Power District (OPPD).

本数据集采用RESON SeaBat™ 7125型多波束测深仪（multibeam echosounder），搭配Applanix船舶位置定向解决方案（Position Orientation Solution for Marine Vessels，POS MV™）WaveMaster系统运动传感器、HYPACK®/HYSWEEP®导航软件，以及Ashtech Z-Xtreme型GPS接收机或Trimble R8型接收机，于2011年洪水事件期间开展密苏里河河床勘测工作。此次勘测覆盖4处地点的15处管道穿越段、3处电厂场址以及1座输电塔。该数据集采用网格格式，每个网格单元的覆盖范围为0.5米×0.5米。每个单元对应的高程值以北美垂直基准面88（North American Vertical Datum, NAVD88）为基准，其值为基于Caris HIPS与SIPS软件计算得到的总传播不确定度（Total Propagated Uncertainty, TPU）所确定的该单元最概然高程。随后Caris软件利用计算得到的TPS值生成组合不确定度与水深估算器（Combined Uncertainty and Bathymetric Estimator, CUBE）表面模型。该表面网格被用于导出网格单元的质心坐标（UTM第14北带的北坐标、东坐标，单位为米）以及单元高程（以NAVD88为基准，单位为米），以此生成该文本数据文件。本数据集由美国地质调查局（U.S. Geological Survey）联合美国环境保护署（Environmental Protection Agency, EPA）以及奥马哈公共电力区（Omaha Public Power District, OPPD）共同采集完成。