NEON AIRBORNE OBSERVATION PLATFORM TEST FLIGHTS: VALIDATION OF AIRBORNE LIDAR AND HYPERSPECTRAL DATA

摘要

The National Ecological Observatory Network (NEON) is a continental-scale research platform that will collect information on ecosystems across the United States to advance our ability to forecast environmental change at the continental-scale. The Airborne Observation Platform (AOP) will fly an instrument suite consisting of a visible-to-shortwave infrared imaging spectrometer, a full waveform light detection and ranging (LiDAR), and a high-resolution digital camera. NEON AOP will focus on several of the terrestrial Essential Climate Variables (ECV) (Stitt, 2011) including bioclimate, biodiversity, biogeochemistry, and land use products. These variables are collected throughout a network of 60 sites across the Continental United States, Alaska, Hawaii, and Puerto Rico via ground-based and airborne measurements. A series of AOP test flights were conducted during the first year of NEON construction with the goal of testing instrument functionality and performance, exercising remote sensing collection protocols, and providing data for algorithm and product validation. These test flights were designed to address the following questions: What is the optimal remote sensing data collection protocol to meet NEON science requirements?; How do aircraft altitude, spatial sampling, spatial resolution, and LiDAR instrument configuration affect data retrievals?; What are appropriate algorithms to derive ECVs from AOP data?; and What methodology should be followed to validate AOP remote sensing products and how should ground truth data be collected? Early test flights around Grand Junction, CO and Ivanpah, CA in May 2012 were focused on radiometric and geometric calibration as well as processing from raw data (Level 0) to corrected (Level 1) products. Next, flights were conducted in the Northeastern U.S. at Harvard Forest in August 2012 with a focus on vegetation chemistry and structure measurements. Vegetation field sampling measurements were performed in coordination with the test flights, including ground LiDAR measurements to validate the airborne LiDAR instrument. An overview of the test flights and ground campaign is provided. Data from the campaign will be available to the science community once processed.