shrub may have 100 pixels or a tree may have 1000, complicating analysis. Second, managed landscapes often are under considerable stress.
Urban plants may have their roots constrained by concrete or compacted by foot traffic, and are subject to much higher temperatures than in nature, due to the effectiveness of urban surfaces in absorbing and reflecting heat. Third, managed landscapes may or may not be maintained appropriately, due to the amount of money involved, labor constraints, and the difficulty in identifying issues occurring high above ground. UAS, building off the precision agriculture and visual imagery industries, have the ability to offer important insights and perspectives on managed landscapes and promise to soon be a key tool in a landscape manager’s toolbox.
Tree Care
Tree care is both science and art, having a number of certifications and sub-disciplines including Certified Arborist and Consulting Arborist, among others. Maintenance and inspection of large trees around structures is difficult and dangerous, and often requires heavy equipment, redundant safety procedures, and specialized climbers.
The tree care industry has just begun to use multirotor UAVs to inspect large trees for issues such as decay, pests, disease, weather damage, nests, and other hazards. UAVs are also used for bid estimates and insurance verification.
The industry needs pilots to fly very close to trees – often a few inches or centimeters from the canopy – to get the highest resolution imagery possible; the skill required to fly this close to tree branches is a key constraint for many tree care companies, for obvious reasons. In a typical flight, a UAV may circle the entire canopy a number of times to check for decay, disease, nutrient deficiency or pests; a pilot may be asked by the arborist to go back to a spot, circle again, or perform some other maneuver to gather more information during the inspection of a tree. No two flights are the same and effective communication between arborist and pilot is important.
Other types of flights for the tree care industry may include estimating the volume of a line of trees for maintenance bids or estimating the spread of disease in a woodlot. During a sales call,
Municipalities and large landscapes typically seek imagery such as this to monitor plant health. Photo courtesy of Joris Voeten, Roofscapes