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

1338994这笔赠款为国家机载激光条带测绘中心(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。采集节点和初始飞行路线轨迹计算和ALSM数据校准功能现在位于休斯顿大学(UH)并执行，数据处理、存档和分发节点位于加州大学伯克利分校(UC-B)。也被称为机载光探测和测距(LIDAR)，ALSM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、地理参考的数字高程模型(DEM)提供了对基本成形过程操作的尺度上的大量地貌特征的前所未有的观测。例如，断层崖、山坡、河道、障碍滩和沙丘、山脉和大陆冰川、火山建筑物和植被树冠结构。从ALSM发展而来的DEM可以用来模拟和促进对地表地貌动态和潜在过程的理解。这项技术还可广泛应用于土木工程和灾害评估，以及过去文明的考古调查，特别是在通过航空摄影测量看不到这种结构的热带环境中。ALSM系统从飞机发射高频激光脉冲(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控制和飞机IMU进行计算。ALSM系统测量单个脉冲的往返行程时间，以反射遇到的表面并返回探测器。回流的强度也记录在UH Gemini系统上。原始的ALSM旅行时间数据与地面全球定位系统(GPS)接收器相位数据以及飞机GPS和IMU数据相结合，生成每个激光从表面或点云返回的XYZ地理参考坐标。S双子座系统的高频激光定位系统允许穿透茂密的植被树冠，并利用开发的后处理程序，可以生成植被树冠上表面和鸟瞰S肉眼所遮挡的裸露地表的地图。NCALM致力于实现三个目标：1)向科学界提供研究质量的激光雷达数据；2)促进机载激光测绘的最新水平；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。***

1338994DietrichThis 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. ***