PLANNING AND EXECUTING UNMANNED AERIAL SYSTEMS (UAS) MISSIONS FOR LANDSLIDE INVESTIGATIONS

Landslides often require a rapid response, along with a sufficient understanding of the magnitude of the event, in order to judge how best to respond for public safety and to evaluate causation. Traditional surveys and site investigations may be lengthy and can pose risk to those involved.

The use of unmanned systems reduces both time and risk by enabling the capture of valuable data and imagery from a safe location. The availability of low-cost Unmanned Aerial Systems (UAS), easy-to-use mission planning software, and the great value of the remotely acquired data, have resulted in a proliferation of unmanned aircraft options and applications over the past few years.

Structure-from-motion (SFM) image processing software provides for the creation of 3-D digital models and orthophotomosaic maps relatively quickly, allowing for timely assessments. Georeferenced point clouds allow for the quantification of slide morphologies, including area and volume measurements. High-resolution triangle mesh digital models provide for the extraction of geologic structure data for kinematic analyses and for the 3D printing of physical models.

Unmanned Aerial Systems (UAS) consist of a remotely controlled aircraft of some type; remote control devices for guiding the aircraft; onboard sensors; software for programming missions, operating sensors, and storing data; an aircraft operator; and/or, a remote pilot in command.

Federal Aviation Administration (FAA) regulations for operating UAS now clarify restrictions and requirements for recreational, commercial, and public-agency use. Software tools for desktop and mobile devices facilitate planning and executing UAS missions and controlling all aspects of aircraft operation, as well as extracting and converting imagery and data into useful information for analysis and visualization.

Several case histories will be discussed presented, including a highway rockslide, a large debris slide, and a United States Marine Corps training exercise. UAS are becoming so simple to operate, and the acquired data are so valuable, that they are likely to be used on greater numbers of projects in the near future, even those that are routine.