Không có mục lục
This image gallery provides examples of Landsat-5 and -7 imagery for a variety of sites in Wisconsin. All images were processed by Jon Chipman formerly of the University of Wisconsin Space Science & Engineering Center and WisconsinView. Please feel free to use these images, with credit to “UW SSEC and WisconsinView.” Thanks for your interest in Landsat views of Wisconsin!
Additional images of the Fond du Lac/southern Lake Winnebago area are available here in a separate image gallery.
Madison Lakes – multitemporal composite
This image of the Madison lakes was created using a variety of digital image processing techniques to enhance three separate Landsat-7 images from different dates in 1999-2000 and combine them into a single composite image. The results provide a dramatic view of an algal bloom that was occurring on Lakes Mendota and Monona in late October, 1999.
Madison Lakes
This Landsat-7 image, acquired on September 2, 2001, shows the Madison Lakes. Wisconsin’s capital city is located on the isthmus between Lake Mendota (top) and Lake Monona (right). Smaller Lake Wingra (center) is surrounded by parks and by the forests and wetlands of the UW Arboretum. At lower right, the Yahara River flows out of Lake Monona and into Lake Waubesa.
The differences in color within and among the Madison lakes result from variation in depth, water clarity, chlorophyll concentration, dissolved organic carbon, and other bio-optical factors. Differences in the numbers and species composition of algae give Lake Mendota and Lake Wingra quite different visual appearances in this Landsat image, with Lake Wingra having more of a green color. A more detailed discussion (with examples) of the use of satellite remote sensing to measure the optical properties of Lake Mendota and Lake Wingra is available here.
Vilas County lakes
This Landsat-7 image, acquired on October 6, 1999, shows a portion of the Northern Highlands lake district, centered on Vilas County. The communities of Minocqua and Woodruff are located at the center of the lower edge of this image, while Boulder Junction is in the upper center and Eagle River is at lower right. The Northern Highlands lake district has one of the highest densities of lakes in North America. Trout Lake – the largest lake in the center of this image – and six other nearby lakes are the focus of long-term studies of lake ecology by researchers at the UW Center for Limnology through the North Temperate Lakes Long-Term Ecological Research program.
Vilas County – map of water clarity
Larger version (300 dpi)
This map of lake water clarity in western Vilas County shows a small portion of a statewide water clarity database for the 1999-2001 time period. The database includes multiple water clarity estimates for over 8,000 lakes, based on automated analysis of 17 Landsat-5 and Landsat-7 images. Analysis of the satellite data was assisted by hundreds of field observations conducted by a network of citizen volunteers coordinated through the Self-Help Citizens’ Lake Monitoring Program at the Wisconsin Department of Natural Resources. More information about the Landsat lake water clarity project is available at https://lakesat.org.
