Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the Lower Atmospheric Process Studies at Elevation—a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. We evaluate a total of 38 individual sUAS with 23 unique sensor and platform configurations using a meteorological tower for reference measurements. We assess precision, bias, and time response of sUAS measurements of temperature, humidity, pressure, wind speed, and wind direction. Most sUAS measurements show broad agreement with the reference, particularly temperature and wind speed, with mean value differences of 1.6 ± 2.6 ∘ C and 0.22 ± 0.59 m/s for all sUAS, respectively. sUAS platform and sensor configurations were found to contribute significantly to measurement accuracy. Sensor configurations, which included proper aspiration and radiation shielding of sensors, were found to provide the most accurate thermodynamic measurements (temperature and relative humidity), whereas sonic anemometers on multirotor platforms provided the most accurate wind measurements (horizontal speed and direction). We contribute both a characterization and assessment of sUAS for measuring atmospheric parameters, and identify important challenges and opportunities for improving scientific measurements with sUAS.

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This paper describes an implementation of a wireless mobile ad hoc network with radio nodes mounted at fixed sites, on ground vehicles, and in small (10kg) UAVs. The ad hoc networking allows any two nodes to communicate either directly or through an arbitrary number of other nodes which act as relays. We envision two scenarios for this type of network. In the first, the UAV acts as a prominent radio node that connects disconnected ground radios. In the second, the networking enables groups of UAVs to communicate with each other to extend small UAVs' operational scope and range. The network consists of mesh network radios assembled from low-cost commercial off the shelf components. The radio is an IEEE 802.11b (WiFi) wireless interface and is controlled by an embedded computer. The network protocol is an implementation of the Dynamic Source Routing ad hoc networking protocol. The radio is mounted either in an environmental enclosure for outdoor fixed and vehicle mounting or directly in our custom built UAVs. A monitoring architecture has been embedded into the radios for detailed performance characterization and analysis. This paper describes these components and performance results measured at an outdoor test range.

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