Calibrated EAARL-B Submerged Topography--Fort Lauderdale, Florida, 2014 (GEOID12A)

Binary point-cloud data of a portion of the submerged environs of Fort Lauderdale, Florida, were produced from remotely sensed, geographically referenced elevation measurements by the U.S. Geological Survey (USGS). Elevation measurements were collected over the area using the second-generation Experimental Advanced Airborne Research Lidar (EAARL-B), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser pulse and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 0.5-1.6 meters. The EAARL, developed originally by the National Aeronautics and Space Administration (NASA) at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A peak sampling rate of 15-30 kilohertz results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.

美国地质调查局（U.S. Geological Survey, USGS）利用遥感地理参考高程测量数据，生成了美国佛罗里达州劳德代尔堡部分水下周边区域的二进制点云数据集（binary point-cloud data）。该区域的高程数据由第二代实验先进机载研究激光雷达（Experimental Advanced Airborne Research Lidar, EAARL-B）采集，这是一款搭载于航空器的脉冲激光测距系统，可用于测量地面高程、植被冠层及海岸地形。该系统通过航空器机身底部的开口向地球表面发射高频激光束，并记录激光脉冲发射与机载接收反射激光信号之间的时间差。航空器以约60米/秒的速度在约300米高度飞越目标区域，可形成宽度约240米的激光扫描带，平均点间距为0.5至1.6米。EAARL最初由美国国家航空航天局（National Aeronautics and Space Administration, NASA）位于弗吉尼亚州的沃洛普斯飞行设施研发，其地面高程测量的垂直分辨率可达3厘米。其峰值采样率为15至30千赫兹，可生成极为密集的空间高程数据集。单次3至4小时的任务即可轻松完成超过100公里海岸线的测绘工作。对该区域生成的高程地图进行分析后，可作为土地开发管理决策的实用工具。