UAS Best Practices: After You Buy
The second article in this two-part series shares George Southard’s insights about what to do after you have researched the various unmanned aerial systems (UAS) available today and bought a UAS that fits your needs. Southard, principal of GSKS Associates, closely follows all technical and regulatory developments related to UAS and gathers practical operating information directly from UAS users.
First and foremost: Do not forget the importance of training your UAS crew. Despite UAS being simpler and less costly than manned aircraft, operating the UAS is very different and requires different skills. The
|Rotary wing UAV have the ability to take-off and land vertically. (Photo Courtesy of NERC, British Geological Survey)|
sensors are less sophisticated and therefore require the operator to be more skilled in the photographic operations. An understanding of lighting conditions and camera settings is necessary to ensure good quality data collection. There is also UAS manufacturer training that teaches the operations and maintenance of specific UAS.
Although UAS are smaller than manned aircraft, requirements for commercial operators in many countries include flight ground school for the pilot in charge. In some cases, current rules state that the pilot in charge will have at least a private pilot’s license to guarantee knowledge of the basics of aviation, air space regulations, navigational charts, and aviation weather. Training and practice with the UAS are absolutely necessary because everything, except getting into the aircraft, is more manual with UAS operations than with traditional manned aerial photo operations.
Practice, practice, practice. Plan a number of small but realistic practice projects that involve different terrain types, varying weather conditions, and different specifications. Try autonomous missions and manually controlled missions. Different project types may require imagery only, low accuracy mapping with no ground control, or high accuracy mapping with ground control. The area of interest may be a rectangular block, an odd shaped block, a dam face or a cell tower. It may include linear features such as transmission lines, roadways, etc., or bodies of water, trees and vegetation. Blocks of images from several flights might need to be mosaicked, and deliverables might include digital elevation models, orthophotos, land use maps, volumetric analysis, thermal maps, etc. The capabilities of the payload will vary widely, depending on whether you are using a small digital camera, a thermal camera, a video camera or a lidar sensor. With practice you will learn how to collect data that can deliver the required end products.
To be most useful, each practice project should be executed from beginning to end, including mission planning, UAS programming, UAS takeoff, data collection, UAS landing, and data processing to produce final products as if they were being delivered to your customer. Use each flight to perfect your procedures until satisfactory results are achieved. Keep careful records of each flight in a log book to use as a future reference.
To practice good safety procedures, develop and use standard communication protocols. The pilot and observer(s) need to use clear and simple messages when speaking over the radio. The person preparing the flight plan and the pilot need to meet before each flight to discuss flight details so there are no surprises in the field. For added safety, create and use check lists for flight planning, pre-flight operations, flight operations, post-flight operations, data handling, and image processing. The whole UAS operations team needs to make mistakes and gain a lot of experience before they are assigned to real (paying) projects.
|Some fixed wing UAV are launched with a catapult. (Photo Courtesy of Texas A&M University LSUASC)|
As a surveying and mapping firm, you probably already have a significant amount of software to complete many types of projects, but unless you have the new versions of software specifically for UAS processing, you may have difficulty producing the desired deliverables.
In general, UAS images lack quality consistency from image to image because the payload tilts and moves with the platform. In contrast, large or medium-format cameras that sit in a gyro-stabilized mount in an aircraft produce consistent images because the sensor is not impacted by aircraft movement (note: the new Aibot X6 hexacopter has a gyro-stabilized mount). Major brands of photogrammetry software have been modified to take into consideration the inconsistencies in UAS imagery, in addition to being able to handle thousands of photos produced at low altitude by the UAS compared to only hundreds for the same area using an airplane. Practice creating a variety of deliverables, such as orthophotos and digital elevation models, to fully understand the nuances of processing UAS data.
“Be careful not to underestimate the effort it takes to become proficient at flying UAS and processing UAS data,” concluded Southard. “The stories that I hear in the field indicate there is a steep learning curve on UAS projects, so it’s best to do your learning before a customer is looking over your shoulder.”