The advent of small, unmanned aircraft systems (sUAS) for atmospheric research promises to provide new opportunities to make meteorological measurements in the lowest layer of the Earth’s atmosphere.  ATDD uses this technology to measure changes of temperature and relative humidity with altitude, map the temperature and character of the Earth’s surface, and perform storm damage assessment in a way never before available that is faster, cheaper, and safer than using manned aircraft.

ATDD’s first sUAS, a DJI S-1000 multi-rotor helicopter, is being used to make several of these measurements.  It is ideally suited to climb vertically to measure how temperature and relative humidity changes with altitude and also to measure characteristics of the Earth’s surface over a large area.  The S-1000 is operated with approval from both the U.S. Federal Aviation Administration (FAA) and NOAA’s Aircraft Operations Center (NOAA/AOC) under visual flight rules (VFR) weather conditions, during daylight hours, and within line of sight of the ground-based pilot.

The S-1000 and its accompanying suite of sensors are being tested at the Knox County Radio Control (KCRC) model flying field near Knoxville, Tennessee to prepare them for upcoming field studies.  To help with this preparation, a meteorological tower has been installed at KCRC to provide reference instruments that can be compared with the S-1000’s instruments to verify their performance.  The latest data from the KCRC tower are available on the web here.

The S-1000 octocopter is fitted with two International Meteorological Systems iMet-XQ temperature, relative humidity, and pressure sensors, as well as a FLIR infrared (IR) camera and a GoPro visible camera to document the surface below the vehicle in multiple wavelengths.  Data from these sensors, along with data from the S-1000’s autopilot, are stored onboard the vehicle and downloaded following each flight.

ATDD recently used the S-1000 to support research to study the formation of severe thunderstorms and tornadoes over Northern Alabama in the spring of 2016.  The Verifications of the Origins of Rotation in Tornadoes Experiment Southeast (VORTEX-SE) experiment used a large suite of instruments to probe the Earth’s boundary-layer both remotely and in-situ. Data from the S-1000 was combined with data from flux towers, microwave radiometers, Doppler radar and lidar (Light Detection and Ranging) systems, as well as radiosonde balloons and space-based remote sensing measurements to help form a more complete picture of how the boundary layer changes prior to the onset of severe thunderstorms and tornadoes.

To support VORTEX-SE, the S-1000 was flown at Auburn University’s Tennessee Valley Research and Extension Center in Belle Mina, Alabama, to measure the development of temperature and relative humidity inversions near sunset, as well as to extend measurements of heat exchange by an eddy covariance flux tower to a larger area than the tower’s natural footprint.  S-1000 flights were also made at Auburn University’s Horticultural Research Station in Cullman, Alabama and to document areas of damage from the March 31, 2016 tornado that struck near Hartselle, Alabama.

The viability of ATDD’s sUAS for performing atmospheric research has been demonstrated, and the program is expected to grow in the coming years.  For example, ATDD recently test flew an MD4-1000 quad-copter in cooperation with NOAA/CCUT and will acquire a fixed-wing sUAS in the near future.

A NOAA Technical Memo on the data gathered during the 2016 VORTEX-SE Field Campaign is available here.pdf document

In 2017, ATDD participated in the second VORTEX-SE Field Campaign from March – April. Temple Lee, Michael Buban and Ed Dumas led the Intensive Operating Periods (IOP). During this time ATDD teams released radiosondes, manned a tethered balloon and obtained vertical profiles using small unmanned aircraft that measured low level temperature and relative humidity . All of these measurements and measurements from other participating scientists were used as input into a numerical model to better understand the influence of terrain, land surface, and boundary layer heterogeneity on tornadic storm development.

More information about the 2016 field campaign can be found in a couple of articles with links below by Christina Edwards of WHNT19 news in Huntsville, Alabama.

A NOAA Technical Memo containing measurements taken during the 2017 VORTEX-SE event is available here.

Our sUAS team also conducted operations during the Land-Atmosphere Feedback Experiment (LAFE) in the summer of 2017 near Lamont, Oklahoma. The sUAS measured temperature and humidity over the lowest 300 meters of the atmosphere and was used to map the Earth’s skin temperature during three intensive observation periods (14 August, 15 August, and 17 August). A Tech Memo on the measurements gathered is available here.
More information about the LAFE experiments is found on the US Department of Energy, Atmospheric Radiation Measurement, LAFE Campaign page.

Special Note

NOAA/ATDD will be operating our small unmanned aircraft systems (sUAS) this Spring at altitudes of up to 1200 feet above ground level. Specific locations are still to be determined but during these flights the sUAS will be in technical compliance with PII information collected in accordance to the presidential memorandum “Promoting Economic Competitiveness While Safeguarding Privacy, Civil Rights, and Civil Liberties in Domestic Use of Unmanned Aircraft Systems.”
We will publish the approximate locations of the flights and the area referred to as the storm damage assessment area (SDAA) at a later date.

If you need Adobe Reader, click on the icon.Get Adobe Reader

DJI S-1000 multi-rotor helicopter fitted with sensors and cameras

The DJI S-1000 multi-rotor helicopter is fitted with meteorological sensors and cameras.

Image of SDAA Operating Area

The 2017 SDAA Operating Area
near Huntsville, Alabama
(click on image to enlarge)