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

1339015 Shrestha该赠款为国家机载激光测绘中心（NCALM）提供了五年的业务支持。 NCALM是一个有两个节点的协作设施。 获取节点和初始飞行路线轨迹计算以及ALSM数据校准功能现在位于休斯顿大学（UH）并在那里执行，数据处理、存档和分发节点位于伯克利的加州大学（UC-B）。 ALSM也被称为机载光探测和测距（LIDAR），它允许以分米级的精度和米到亚米的空间分辨率测量表面地形特征。 从原始ALSM数据（点云）处理的高分辨率，地理参考，数字高程模型（DEM）提供了前所未有的大量地貌特征的观测，在基本塑造过程的规模。例子包括断层崖、山坡、河道、障壁海滩和沙丘、山地和大陆冰川、火山大厦和植被冠层结构。 从ALSM开发的DEM可用于模拟和促进对地表地貌动态和相关底层过程的理解。 该技术还广泛应用于土木工程和灾害评估以及对过去文明的考古调查，特别是在热带地区，这些结构通过航空摄影测量是不可见的。 ALSM系统以高频率从飞机发射激光脉冲（通常为毫焦耳功率的Nd：YAG），飞机的位置和方向通过机载和地面GPS控制以及飞机IMU来计算。 ALSM系统测量单个脉冲从遇到的表面反射并返回到探测器的往返行程时间。 回报的强度也记录在UH GEMINI系统上。 原始ALSM旅行时间数据与地面全球定位系统（GPS）接收器相位数据和飞机GPS和IMU数据相结合，以生成每个激光从地面返回的xyz地理参考坐标，或者？点云？ GEMINI系统？的高频率激光张贴允许密集的植被冠层的渗透，并与发达国家的后处理程序，可以产生的植被冠层和裸露的地球表面，是从鸟类阻碍的上表面的地图？s eye view. NCALM致力于实现三个目标：1）为科学界提供研究质量的LiDAR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。 ***

1339015ShresthaThis grant provides five years of operational support for the National Center for Airborne Laser Swath Mapping (NCALM). NCALM is a collaborative Facility with two nodes. The acquisition node and initial flight line trajectory calculations and ALSM data calibration functions are now located and performed at the University of Houston (UH) and the data processing, archival and distribution node is at the University of California at Berkeley (UC-B). Also known as airborne Light Detection and Ranging (LIDAR), ALSM allows for the measurement of surface topographic features with decimeter-level accuracies and meter to sub-meter spatial resolution. High resolution, georeferenced, digital elevation models (DEMs) processed from raw ALSM data (point clouds) offer unprecedented observations of a multitude of geomorphic features at the scales at which fundamental shaping processes operate. Examples include, fault scarps, hill slopes, river channels, barrier beaches and sand dunes, mountain and continental glaciers, volcanic edifices and vegetative canopy structure. DEMs developed from ALSM can be used to model and advance understanding of the dynamics of surface landforms and the underlying processes responsible. The technique also has a wide range of applications in civil engineering and hazards assessments and for archaeological investigations of past civilizations modification of landscapes, especially in tropical environs where such structures are invisible via airborne photogrammetry. ALSM systems fire laser pulses (typically Nd:YAG at milliJoule powers) at high frequency from an aircraft whose position and orientation are accounted for via on board and ground GPS control and an aircraft IMU. The ALSM system measures the round trip travel time for individual pulses to reflect off encountered surfaces and return to a detector. The intensity of returns is also recorded on the UH GEMINI system. Raw ALSM travel time data is combined with ground Global Positioning System (GPS) receiver phase data and aircraft GPS and IMU data to generate xyz georeferenced coordinates of each laser return from the surface or ?point clouds.? The GEMINI system?s high frequency laser postings allows for penetration of dense vegetative canopies and, with developed post processing routines, can yield maps of both the upper surface of vegetative canopy and the bare Earth surface that is obstructed from a bird?s eye view. 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. ***