Use of UAV images for precision agriculture and environmental applications

点击翻译按钮获取中文摘要

For several environmental applications, airborne /satellite images are less suitable than unmanned aerial vehicles (UAV) images. UAVs can operate at much low altitudes that results in high spatial resolution images. They are more mobile, fast, adaptable, and easier to use. Furthermore, they allow surveys in a repetitive and much more cheaply way. Under a NSERC-CRD grant, we are developing a new multispectral UAV camera for crop management. The requested Discovery Grant will built upon this NSERC-CRD grant and several on-going projects. First, we will improve the automated method we developed to count apple orchard trees from UAV images to detect damaged trees. We will also test the method to other types of orchards. Second, we will test the use of UAV images for monitoring eelgrass bed restoration, in conjunction to a successful Environment Canada grant supporting field and UAV data acquisition. Third, UAV images will be used to monitor natural vegetation recolonization on recently restored salt marshes. For the three projects, novel methods that use spectral and textural image information will be developed. Given the high spatial resolution of the images, advanced classifiers will be tested in addition to standard pixel-based classifiers. UAV image processing can be challenging because UAV are more susceptible to windy conditions, which can affect the viewing and illumination geometries. Also, the low UAV flying altitude requires more images to cover the area, which can lead to increasing of the sensor temperature and of the probability of variable weather conditions. For the eelgrass project, an additional challenge is to consider the effect of the water column on the image acquisition and processing. Also for both coastal applications, image acquisition should take into account potential sun glint effects. The research is important to those who need an affordable and flexible monitoring tool that provides high spatial images. The damaged tree mapping method will be used by growers to assess the status of their orchards and by crop insurance agencies to determine compensations to growers. The eelgrass mapping method will be used by the Department of Fisheries and Oceans and other NGO groups working on eelgrass restoration projects. The salt marsh mapping method will be used by Ducks Unlimited Canada to monitor salt marsh restoration. Beyond these three applications, the research will also produce novel methods for UAV image processing that can be used in other applications. The proposed research will contribute to the development in Canada of a booming commercial UAV sector that is projected to more than quadruple in sales worldwide over the next five years.