2000 Aerial Photo Mosaics - Upper Mississippi River System -- Pool 13

The U.S. Geological Survey's Upper Midwest Environmental Sciences Center (UMESC) collects aerial photography of the Upper Mississippi River System (UMRS) floodplain on a regular basis. These data are used to support the Center's long-term goals of understanding the UMRS and developing useful products for the Long Term Resource Monitoring Program (LTRMP). In 2000, 1:16,000-scale true color aerial photos were collected on the Mississippi River from Cairo, IL to Minneapolis, MN and the on Illinois River from its confluence with the Mississippi near Grafton, IL to Lake Michigan/Chicago, IL. The photos were collected using a 60% stereo overlap between photos in the same flight line and a 30% overlap between flight lines. At the time this document was prepared, UMESC was in the process of scanning, georeferencing and compiled approximately every other photo into georeferenced mosaics for the navigation pools. These mosaics are served as compressed .sid images, so they'll be easier to download vial the Internet. Note: While the photos have been georeferenced, they have not been orthorectified.美国地质调查局（U.S. Geological Survey）中北部环境科学中心（Upper Midwest Environmental Sciences Center, UMESC）定期采集密西西比河上游流域（Upper Mississippi River System, UMRS）泛滥平原的航空摄影数据。此类数据用于支撑该中心研究密西西比河上游流域、为长期资源监测项目（Long Term Resource Monitoring Program, LTRMP）开发实用产品的长期目标。2000年，该中心采集了密西西比河（伊利诺伊州开罗至明尼苏达州明尼阿波利斯段）与伊利诺伊河（伊利诺伊州格拉夫顿附近与密西西比河汇流处至伊利诺伊州芝加哥/密歇根湖段）的1:16000比例尺真彩色航空影像。本次采集采用同航线影像间60%的立体重叠率、航线间30%的重叠率。在本文件编制之时，UMESC正开展影像扫描与地理配准工作，并已将约半数影像拼接为适配通航河段的地理配准镶嵌图。该类镶嵌图以压缩.sid格式存储，便于通过互联网下载。注：尽管上述影像已完成地理配准，但尚未进行正射校正。