The term "drone" rightfully brings up negative images of unmanned aerial vehicles (UAVs) doing terrible things—or, rather, allowing their human operators to do terrible things—like killing 50 civilians for every one "militant" in Pakistan.
But UAVs or drones can also be put to good use. For example, Michigan State University just acquired a drone that will fly over agricultural fields and monitor the health of farmers' crops. This will allow farmers to better manage their fields, and to hopefully use less water, fertilizer and herbicides, said Bruno Basso, an ecosystem scientist at the university.
So far, the system has been tested in Europe to prove that it works but has yet to be flown over crop fields in the states, Basso said. But previous tests have shown that it is capable of measuring the nitrogen content of plants—whether or not they may need fertilizer—and if they need water.
The device, which is about six feet by six feet and has four rotors to keep it aloft, is designed to fly about 100 feet above crop fields and take high-resolution images of entire farms, with enough detail that it can make out the identity of individual plants, Basso said.
It contains three instruments. The first, a thermal imager, allows it to take the temperature of plants, which can be used to see if the plants need water. The second is a hyperspectral radiometer, enabling the device to see when plants require nitrogen. Finally, a laser scanner deduces plant heights, which tells how well plants are generally doing and if they are on course (e.g. corn that's "knee-high by the 4th of July," as the old saying goes).
The plan is to soon deploy the drone over the fields of 75 farmers in the summer, with 25 each in the states of Michigan, Illinois and Iowa. In those locations it will be deployed two or three times per year. Information gathered with the sensors will be fed into a computer model that analyzes the data and helps guide the decisions of farmers, such as where to apply fertilizer, Basso said.
Basso said he's still waiting on final permissions from the Federal Aviation Administration, but expects to get it any day. Ironically, he said, he would have had to do much less if he just wanted to use the UAV recreationally, but since it's part of a research program, several permits had to be secured, which is a time-consuming process. Thankfully, the drone flies rather low to the ground, presenting little to no risk to larger aircraft, he added.
Basso said he thinks drones could be used in the future to help save farmers' time and resources, leading to the conservation of water and a need for less fertilizer and pesticides. These could bolster the growing precision agriculture movement and could be a boon for the environment.
Another agricultural use for drones is more efficient use of pesticides. In Japan, one type of UAV has been used for about 20 years to apply pesticides to steep hillsides where tractors may not be able to reach at all, Ben Gielow, a spokesman for the Association for Unmanned Vehicle Systems International, told National Geographic. "Agriculture, far and away, is going to be the dominant market for UAV operations," he said.
Besides agricultural uses, drones are also being used to protect wildlife. The U.S. Geological Survey, for example, has used drones to count sandhill cranes. The WWF employs UAVs to look out for poachers in African wildlife reserves. And scientists have used conservation drones to monitor orangutan nests in Sumatra and Borneo.
NASA is also using drones to monitor hurricanes. In the so-called Hurricane and Severe Storm Sentinel mission, the agency is in the midst of testing two Global Hawk drones to fly over storms that would be difficult for human operators to get to. The effort promises to improve scientists’ understanding of hurricane intensification and create better cyclone forecasts.