SUAS-Based Remote Sensing in Mountainous Areas: Benefits, Challenges, and Best Practices

Abstract

Small unmanned aircraft systems (sUAS) offer key benefits over manned aircraft and satellite platforms used for remote sensing research, such as high spatial resolution, portability, simplicity of implementing ground control, affordability, and lack of reliance upon third-party imagery providers. Mountainous areas, which we define as locations that are higher than 2500 m in elevation and that contain slopes greater than 25°, pose a number of challenges to sUAS mapping operations that other environments do not, including reduced aircraft performance, cold temperatures, high winds, and limited accessibility. The purpose of our paper is to identify these challenges and discuss workflows used to mitigate these difficulties to achieve greater logistical and operational efficiency. We used a DJI Inspire 2 multirotor aircraft to conduct mapping missions in remote, mountainous areas to support subalpine forest inventory and assessment in Nevada and southern Utah. We identified several potential obstacles to collecting high-quality aerial image data in environments with high topographic variability and landscape heterogeneity. We found that sUAS are very useful and practical when performing mapping missions in these circumstances when operators account for potential environmental limitations (e.g., poor weather, shortened flight times due to atmospheric conditions, line-of-sight challenges, difficulty implementing ground control across steep sites, ensuring applicable aviation regulations are observed) and technological capabilities (terrain following, flight duration, etc.). This work has implications for a wide variety of scientific and management disciplines that involve low-altitude remote sensing research in mountainous areas.