Beach profile data for the Elwha River Delta, 2017-03-05

Data were collected using GNSS survey methods, with a differential GPS operating in Real Time Kinematic (RTK) mode. Data from prior to 2013 were typically collected with a Magellan ProMark 3 traditional RKT-DGPS system (i.e. local base station and rover), with the base station sited on survey control markers installed in 1996, with survey control coordinates referenced to NAD83(CORS91). Starting in 2013 survey data were typically collected with an AshTech ProMark 200 RTK-DGPS system connected to the Washington State Reference Network. Survey data collected between January and November 2013 are referenced to NAD83(CORS96), and after November 2013 to NAD83(2011).

本数据集采用全球导航卫星系统（GNSS）测量方法采集，所用差分GPS（DGPS）设备运行于实时动态（RTK）模式。2013年之前采集的数据，通常采用麦哲伦（Magellan）ProMark 3型传统RTK-DGPS系统（即本地基准站与流动站架构），基准站设于1996年布设的测量控制标记点，其测量控制坐标以NAD83(CORS91)为基准坐标系。2013年起，数据采集通常采用连接至华盛顿州参考站网的阿什泰克（AshTech）ProMark 200型RTK-DGPS系统。其中，2013年1月至11月间采集的测量数据采用NAD83(CORS96)作为基准坐标系，2013年11月之后采集的数据则采用NAD83(2011)作为基准坐标系。