Hyperspectral Imagery for the Main Eight Hawaiian Islands:Oahu (207a-0613-272217)

This project is a cooperative effort among the National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Monitoring and Assessment; the University of Hawaii; and Analytical Laboratories of Hawaii, LLC. The goal of the work was to develop coral reef mapping methods and compare benthic habitat maps generated by photointerpreting georeferenced color aerial photography, hyperspectral and IKONOS satellite imagery. The enhanced spectral resolution of hyperspectral and control of bandwidths of multispectral data yield an advantage over color aerial photography particularly when coral health and time series analysis of coral reef community structure are of interest. Depending on the type of instrument, a spectral imaging system can be utilized to see multiple colors from ultraviolet through the far infrared range. The AURORA hyperspectral imaging system collected 72 ten nm bands in the visible and near infrared spectral range with a 3 meter pixel resolution. The data was processed to select band widths, which optimized feature detection in shallow and deep water. Photointerpreters can accurately and reliably delineate boundaries of features in the imagery as they appear on the computer monitor using a software interface such as the Habitat Digitizer.

本项目由国家海洋服务局（National Ocean Service）、国家沿海海洋科学中心（National Centers for Coastal Ocean Science）、沿海监测与评估中心（Center for Coastal Monitoring and Assessment）、夏威夷大学以及夏威夷分析实验室有限责任公司（Analytical Laboratories of Hawaii, LLC）合作开展。本研究的目标为开发珊瑚礁制图方法，并对比通过对地理参考彩色航空摄影、高光谱（hyperspectral）影像以及IKONOS卫星影像开展目视解译所生成的底栖生境地图。高光谱数据具备增强的光谱分辨率，且多光谱数据可实现带宽可控，相较彩色航空摄影具备显著优势，尤其在关注珊瑚健康状况与珊瑚礁群落结构时序分析的场景中。依据仪器类型的差异，光谱成像系统（spectral imaging system）可实现从紫外到远红外波段范围内的多光谱信息采集。AURORA高光谱成像系统在可见光与近红外光谱范围内采集了72个10纳米带宽的波段，像素分辨率为3米。研究人员对采集得到的数据进行处理以筛选最优波段带宽，从而优化浅水区与深水区的地物特征识别效果。影像解译人员可借助诸如生境数字化器（Habitat Digitizer）这类软件界面，在计算机显示器上精准且可靠地勾绘影像中各地物的边界。