This SPOT multi-spectral image has a ground resolution of 20m and covers a total area of about 20km x 20km south of the city of Windsor, Ontario. The towns of Harrow and Kingsville can be identified by its lack of colour and characteristic grid patterns of street. Numerous homes and farms are located along all of the roads in the region. The three spectral bands available from this sensor were displayed in blue, green and red to create this colour composite image. The colour combination shown, gives the healthy, dense vegetation a very red colour.
Water appears dark blue to black, depending on the sediment content and water depth.
Agricultural agencies, farming groups and governments use such satellite images to identify crops and monitor crop growth in an effort to forecast yields that will assist in setting crop prices. Information is also used to determine assistance that may be needed if there is a crop failure and to map crop destruction due to environmental disasters. The combination of green, red and near-infrared sensitivites depicted as blue, green and red respectively is a traditional and useful way of showing vegetated areas where the vegetation type, health or density is of interest. The inclusion of the near-infrared band is the critical choice, since this part of the electromagnetic spectrum is particularly responsive to vegetation. For instance, vegetation under stress often shows much reduced reflectance in the near-infrared even before it shows signs that are visible to the naked eye.