Tables of file names, times, and locations of images collected during unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (text files)

These text files contain tables of the file names, times, and locations of images obtained from an unmanned aerial systems (UAS) flown in the Cape Cod National Seashore. The objective of the fieldwork was to evaluate the quality and cost of mapping from UAS images. Low-altitude (approximately 120 meters above ground level) digital images were obtained from cameras in a fixed-wing unmanned aerial vehicle (UAV) flown from the lawn adjacent to the Coast Guard Beach parking lot on 1 March, 2016. The UAV was a Skywalker X8 flying wing operated by Raptor Maps, Inc., contractors to the U.S. Geological Survey. U.S. Geological Survey technicians deployed and mapped 28 targets that appear in some of the images for use as ground control points. All activities were conducted according to Federal Aviation Administration regulations and under a National Park Service Scientific Research and Collecting Permit, study number CACO-00285, permit number CACO-2016-SCI-003. Two consecutive UAS missions were flown, each with two cameras, autopilot computer, radios, and a global navigation satellite system (GNSS) positioning system as payload. The first flight (f1) was launched at approximately 1112 EST, and followed north-south flight lines, landing at about 1226 EST. Two Canon Powershot SX280 12-mexapixel digital cameras, designated rgb1 and rgb2 made images during this flight. The second flight (f2) was launched at 1320 EST and followed east-west flight lines, landing at 1450 Eastern Standard Time (EST). Prior to f2, rgb2 was replaced with a Canon SX280 modified with a Schott BG 3 filter to emphasize light at near-infrared wavelengths, designated nir1. Rgb1 and nir1 made images during this second flight. The four files are tables of images obtained from the two cameras during the two flights. These tables, which are text files of comma-separated values, contain the image file name, date and time (Universal Time; UT), longitude and latitude (WGS84 decimal degrees), easting and northing (NAD83(2011) UTM Zone 19 North meters, obtained by conversion of the latitude and longitude), and elevation (approximate meters above mean sea level) determined from the UAS GNSS system. Note that this location information was only used to determine proximity of images, and was replaced with calculated camera locations in photogrammetric processing.

本批文本文件包含从科德角国家海岸（Cape Cod National Seashore）执行飞行任务的无人机系统（unmanned aerial systems, UAS）所获影像的文件名、拍摄时刻与位置信息表格。本次野外作业的目标为评估基于无人机系统影像进行测绘的质量与成本。2016年3月1日，研究团队于紧邻海岸警卫队海滩停车场的草坪处，操控固定翼无人飞行器（unmanned aerial vehicle, UAV）搭载的相机获取了海拔约120米的低空数码影像。该无人飞行器为天行者X8飞翼，由美国地质调查局（U.S. Geological Survey）的承包商——猛禽地图公司（Raptor Maps, Inc.）负责操控。美国地质调查局的技术人员布设并测绘了28个出现在部分影像中的目标，作为地面控制点（ground control points）使用。所有作业均符合美国联邦航空管理局（Federal Aviation Administration）相关规定，并持有美国国家公园管理局（National Park Service）颁发的科研与采集许可，研究编号为CACO-00285，许可编号为CACO-2016-SCI-003。本次任务共开展两次连续的无人机系统飞行任务，每架次均搭载两台相机、自动驾驶计算机、无线电设备以及全球导航卫星系统（global navigation satellite system, GNSS）定位系统作为载荷。首次飞行任务（f1）于美国东部标准时间（Eastern Standard Time, EST）约11时12分起飞，沿南北向飞行航线飞行，于约12时26分降落。本次飞行中，两台编号为rgb1与rgb2的佳能PowerShot SX280 1200万像素数码相机完成了影像采集。第二次飞行任务（f2）于美国东部标准时间13时20分起飞，沿东西向飞行航线飞行，于14时50分降落。在f2任务开展前，rgb2相机被更换为一台加装肖特BG3滤镜以增强近红外波段光线采集的佳能SX280相机，编号为nir1。本次飞行任务中，由rgb1与nir1两台相机完成影像采集。本批次共4个文件，均为两次飞行任务中两台相机所获影像的信息表格。此类表格采用逗号分隔值（comma-separated values）格式的文本文件，包含影像文件名、日期与时刻（协调世界时，Universal Time, UT）、经纬度（WGS84十进制度）、东向与北向坐标（基于纬度经度转换得到的NAD83(2011) UTM 19北带米制单位），以及由无人机系统全球导航卫星系统测算得到的海拔高度（近似平均海平面以上米数）。需注意，上述位置信息仅用于判断影像间的邻近关系，在摄影测量处理流程中，将采用计算得到的相机位置替代该类位置信息。