Collaborative Research: Facility Support for Operation of the National Center for Airborne Laser Mapping (NCALM)

该合同继续得到国家机载激光测绘中心（NCALM）的支持，该中心是休斯顿大学的操作设施和加州大学伯克利分校的数据处理中心之间的合作。也被称为机载光探测和测距（LiDAR），机载激光测绘允许以非常高的精度和空间分辨率测量表面地形特征。收集的数据用于构建非常详细的数字高程模型（DEM），该模型提供了前所未有的高分辨率地形特征表示，并阐明了塑造地形特征的过程。例子包括断裂带、山坡、河道、屏障海滩和沙丘、山脉和大陆冰川、火山大厦和森林冠层的结构。该设施为研究人员提供了收集数据所需的复杂技术和操作支持，以及将数据转换为视觉产品所需的专业知识。由激光雷达开发的dem在土木工程和灾害评估中有着广泛的应用，可以看到在特定的时间间隔内陆地表面移动了多少，以及在考古调查中，过去的文明如何改变了景观，特别是在热带地区，这些结构被茂密的森林覆盖所掩盖。NCALM致力于实现三个目标：1)为科学界提供研究质量的激光雷达数据；2)推进机载激光测绘的最新技术；3)培训和教育研究生，以满足学术界、政府和私营部门快速增长的需求。这份持续的合同将允许NCALM通过灵活的便携式直升机系统增强收集平台，扩大多波长激光雷达和同步高光谱图像的使用，与其他NSF中心合作探索无人飞机，专注于开放源代码软件工具和方法，用于时间间隔激光雷达收集之间的变化检测。并提供研讨会和社区参与，传播NCALM获得和发展的激光雷达知识。机载激光系统从飞机发射高频激光脉冲，其位置和方向通过机载和地面全球定位系统（GPS）控制和飞机惯性测量单元（IMU）监测。仪器测量单个脉冲从遇到的表面反射并返回到探测器的往返旅行时间。原始旅行时间数据与位置信息相结合，生成从表面或“点云”返回的每个激光的地理参考坐标。该系统的高频激光发射允许穿透密集的植被冠层，并且通过先进的后处理程序，可以生成植被冠层的上表面和被鸟瞰遮挡的裸露地球表面的地图。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award continues the support of the National Center for Airborne Laser Mapping (NCALM), which is a collaboration between the operational facility at the University of Houston and the data-processing center at the University of California Berkeley. Also known as airborne Light Detection and Ranging (LiDAR), airborne laser mapping allows for the measurement of surface topographic features with very high accuracies and spatial resolution. The data collected are used to construct very detailed digital elevation models (DEM) that offer an unprecedented high-resolution representation of topographic features and illuminate the processes that shape them. Examples include fault scarps, hill slopes, river channels, barrier beaches and sand dunes, mountain and continental glaciers, volcanic edifices and the structure of the forest canopy. This facility gives researchers access to the sophisticated technology and operational support needed to gather the data and the expertise required to convert that data into visual products. DEMs developed from LiDAR have a wide range of applications in civil engineering and hazards assessments to see how much the land surface has moved over a specific time interval, and in archaeological investigations of how past civilizations have modified landscapes, especially in tropical regions where such structures are hidden from view by dense forest cover. NCALM is dedicated to meeting three goals: 1) providing research-quality LiDAR data to the scientific community, 2) advancing the state of the art in airborne laser mapping, and 3) training and educating graduate students to meet the rapidly growing needs of academia, government, and the private sector. This continuing award will allow NCALM to augment collection platforms with a flexible and portable helicopter-based system, expand the use of multi-wavelength LiDAR and coincident hyperspectral imagery, work with other NSF centers to explore unmanned aircraft, focus on open-source software tools and methodology for change detection between temporally spaced LiDAR collections, and provide workshops and community engagement to disseminate the LiDAR knowledge that NCALM has acquired and developed. Airborne laser systems fire laser pulses at high frequency from an aircraft whose position and orientation are monitored via on-board and ground Global Positioning System (GPS) control and an aircraft Inertial Measurement Unit (IMU). The instrumentation measures the round-trip travel time for individual pulses to reflect from encountered surfaces and return to a detector. Raw travel-time data are combined with position information to generate georeferenced coordinates of each laser return from the surface or "point clouds." The system's high-frequency laser postings allow for penetration of dense vegetative canopies and, with developed post-processing routines, can yield maps of both the upper surface of the vegetative canopy and the bare Earth surface that is obstructed from a bird's-eye view.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.