Wetlands are lands that are wet for at least part of the year. They provide critical feeding, resting and breeding habitat to many kinds of waterfowl, amphibians and reptiles, fish, small mammals and dragonflies. Thanks to a collaboration between the Forest Preserve District, the Department of Geographic Information Systems (GIS) of the Cook County Bureau of Technology and the US Fish and Wildlife Service, land managers now have an exciting new tool that helps them “see” Cook County wetlands like never before.
Over the past year, private contractors Merrick and Company, along with Galileo Group, Inc., have been flying a Cessna 172 Skyhawk at 5,500 feet in a lawn mower-like pattern of east and west parallel flight lines over all of Cook County. Installed in the fuselage of this small airplane is a hyperspectral imaging system which leaves just enough room for a pilot and a sensor operator. This hyperspectral sensor is not your average camera: about the size of a bread box and weighing about 80 pounds, this ultra-high-tech device is integrated with a high precision Global Positioning System (GPS) and Inertial Measurement Unit. Together, these cutting-edge technologies can collect a three-dimensional data cube consisting of hundreds of images, each representing a different wavelength across the visible and near infrared portion of the electromagnetic spectrum. The device does this all while recording the aircraft’s altitude, speed, longitude, latitude, flight heading, pitch, roll and yaw 100 times per second in order to adjust for the plane’s every wobble and slide, atmospheric interference and even for changes in the angles from which the images are taken.
When all the imagery becomes available to ecologists this month, the Forest Preserve District will use it to identify every wetland on its property and better define the boundaries of each. The technology, called hyperspectral imagery, is accurate to one meter, which means the District will be able to determine wetland edges very precisely. The detailed information will be included in the National Wetlands Inventory.