Search for: All records

Abstract Existing motor vehicle pollutant measurement techniques, including those that employ ground-based and multirotor small uncrewed aircraft system (sUAS) methods, can accurately measure traffic-related air pollution (TRAP) concentrations at a single location. However, these techniques often lack the mobility to assess pollutant trends across a large horizontal area. Fixed-wing sUAS represents an alternative instrument platform compared to ground-based systems and multirotor sUAS, as fixed-wing sUASs are able to carry air pollutant monitor payloads, have extended endurance, and offer expansive three-dimensional ranges across a field site. To demonstrate the utility of fixed-wing sUAS for urban TRAP assessment, we conducted two flights using a Super Robust Autonomous Aerial Vehicle–Endurant Nimble (RAAVEN) sUAS [University of Colorado (CU) Boulder] at a large field site adjacent to a major highway in Erie, Colorado. Concentrations of solid particulate matter (PM₁₀) and gas-phase (carbon monoxide) pollutants displayed decay as a function of altitude. During the morning flight, PM₁₀concentrations decreased from 19.0μg m⁻³at ground level to a minimum concentration of 14.3μg m⁻³at 90 m above ground level. During the afternoon flight, concentrations of PM₁₀displayed minimal vertical stratification, ranging from 8.9 at ground level to 10.0μg m⁻³at 45 m above ground level. Similarly, pollutants displayed decreasing concentrations as the horizontal distance from the roadway increased. Concentrations of TRAP may be significantly elevated in the area both above and beyond roadways, which contribute to additional pollutant exposure from on-road pollution sources. This study demonstrated that the general behavior of TRAP in near-road environments and that the use of fixed-wing sUAS are viable option for urban air quality measurements. Significance StatementThis study represents one of the first uses of a fixed-wing small uncrewed aircraft system (sUAS) to assess near-roadside concentrations of traffic-related air pollution (TRAP) in urbanized areas. We found that local meteorology, including local wind and solar radiation, had a substantial influence on the concentrations of common air pollutants, including particulate matter, black carbon, carbon monoxide, and carbon dioxide. Furthermore, we found large-scale spatiotemporal variation in pollutant concentrations as a function of the vertical and horizontal distance from the highway, indicating that diminished spatial variation employed in multirotor sUAS studies may not be sufficient to fully assess TRAP in roadside environments. 

A method for calibrating a multi-hole probe (MHP) used for inertial wind vector measurements from a small Uncrewed Aircraft System (sUAS) is presented. The first phase of the calibration process is broken into three parts: Obtaining reference airspeed, angle of attacks and side slip angles; calibrating MHPs with experimental data; mitigating bias errors to improve calibrations.The method follows the established wind tunnel calibration procedures and includes two additional steps to increase calibration accuracy. The calibration process begins with a computational fluid dynamics (CFD) study on blockage effects in the wind tunnel. CFD results indicate nontrivial deviations of the mean flow due to blockage in wind tunnel test section. Analysis shows a linear relationship between experimental setup position and the resulting deviation from unidirectional flow. The relationship is incorporated into the routine to develop a calibration model. This augments previously demonstrated techniques by processing experimental data from the probe using CFD results. Then the model is refined by removing experimental bias angles. The next phase is to account for upwash effects caused by the sUAS lifting surfaces. Initial CFD analysis has been conducted to determine the relationship between the perceived airframe orientation measured from the relative wind, and the angle of attack measured by the MHP. Preliminary results show that there is a measurable linear relationship between the perceived and actual angles of attack. The objective these additional steps is to increase the accuracy of MHP calibration and characterize the error in inertial wind vector measured during field experiments. 

A0 level data from HELiX Uncrewed Aircraft System correspond to the raw data in Matlab format collected in the Central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Synchronized and quality-controlled B1 level data are available in the Arctic Data Center. Users are encouraged to primarily use the B1 level data for analysis (doi:10.18739/A2GH9BB0Q). Raw data are the initial inputs in the processing routines to obtain the B1 and A1 level data (doi:10.18739/A2M90243X). Matlab files include hemispheric irradiance measurements from Kipp and Zonen pyranometers and thermodynamic parameters from Vaisala RSS421 sensors. Autopilot positions and attitudes, along with gimbal attitudes are also provided. Each field of measurements has its own time stamped based on a common clock and associated acquisition frequency. As no Coordinated Universal Time (UTC) time was provided in the FlexLogger acquisition files, the additional A0_PixHawk Matlab files obtained directly from the PixHawk autopilot are used to add UTC time for B1 level data. Please contact the authors if you need to use this dataset. More information on the data and method can be found in de Boer, G. R. Calmer, G. Jozef, J. Cassano, J. Hamilton, D. Lawrence, S. Borenstein, A. Doddi, C. Cox, J. Schmale, A. Preußer and B. Argrow (2022): Observing the Central Arctic Atmosphere and Surface with University of Colorado Uncrewed Aircraft Systems, Nature Scientific Data, in prep. 

Abstract Over a five-month time window between March and July 2020, scientists deployed two small uncrewed aircraft systems (sUAS) to the central Arctic Ocean as part of legs three and four of the MOSAiC expedition. These sUAS were flown to measure the thermodynamic and kinematic state of the lower atmosphere, including collecting information on temperature, pressure, humidity and winds between the surface and 1 km, as well as to document ice properties, including albedo, melt pond fraction, and open water amounts. The atmospheric state flights were primarily conducted by the DataHawk2 sUAS, which was operated primarily in a profiling manner, while the surface property flights were conducted using the HELiX sUAS, which flew grid patterns, profiles, and hover flights. In total, over 120 flights were conducted and over 48 flight hours of data were collected, sampling conditions that included temperatures as low as −35 °C and as warm as 15 °C, spanning the summer melt season. 

This dataset includes unprocessed raw data from DataHawk2 fixed-wind uncrewed aircraft system (UAS) flights that were conducted in the central Arctic Ocean over sea ice during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Synchronized and quality controlled data are available in the Arctic Data Center at doi:10.18739/A22Z12Q8X for data provided at their native frequency logged on board the aircraft’s secure digital (SD) card (A1 level files), or at doi:10.18739/A2Z60C34R for data interpolated to a common 10 hertz (Hz) clock (B1 level files). Users are encouraged to primarily use the B1 level data for analysis. Please contact the authors if you plan to use this dataset. More information on data collection with the DataHawk2 can be found in de Boer, G. R. Calmer, G. Jozef, J. Cassano, J. Hamilton, D. Lawrence, S. Borenstein, A. Doddi, C. Cox, J. Schmale, A. Preußer and B. Argrow (2022): Observing the Central Arctic Atmosphere and Surface with University of Colorado Uncrewed Aircraft Systems, Nature Scientific Data, submitted. 

Data are available for download at: https://arcticdata.io/data/10.18739/A2RV0D21Z/ This dataset consists of multispectral imagery data products produced from HELiX uncrewed aircraft system (UAS) flights that were conducted over or near sea ice during the MOSAiC expedition. These data were produced from raw multispectral imagery acquired by the Helix’s gimbal-mounted RedEdge-MX camera. Additional data from the Helix UAS’ other sensors, which consist of hemispheric irradiance measurements from two Kipp and Zonen pyranometers and thermodynamic parameters from two Vaisala RSS421 sensors can be found in Radiance Calmer, Gijs de Boer, Jonathan Hamilton, Dale Lawrence, Steve Borenstein, et al. 2021. HELiX Uncrewed Aircraft System data from the Multidisciplinary drifting Observatory for the Study of Arctic Climate campaign, A1 level data. Arctic Data Center. doi:10.18739/A2M90243X (A1 data) or Radiance Calmer, Gijs de Boer, Jonathan Hamilton, Dale Lawrence, Steve Borenstein, et al. 2021. HELiX Uncrewed Aircraft System data from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Campaign. Arctic Data Center. doi:10.18739/A2GH9BB0Q (B1 data). Three main flight types were conducted with the Helix: a grid pattern, hover, and profile. Pix4D was used to produce five (one for each channel of the camera) orthomosaics, reflectance maps, and colorized index maps for all flight types. A video of the images taken during the flight, including an image scale, UTC time, and altitude overlay was produced for each profile flight. More information on the data and methods can be found in de Boer, G. R. Calmer, G. Jozef, J. Cassano, J. Hamilton, D. Lawrence, S. Borenstein, A. Doddi, C. Cox, J. Schmale, A. Preußer and B. Argrow (2021): Observing the Central Arctic Atmosphere and Surface with University of Colorado Uncrewed Aircraft Systems, Nature Scientific Data, in prep. 

The dataset is derived from HELiX Uncrewed Aircraft System flights that were conducted in the Central Arctic Ocean over sea ice during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. The data include Universal Coordinated Time (UTC), downwelling and upwelling shortwave radiation measurements, and position and attitude from the Uncrewed Aircraft System (UAS). Temperature, relative humidity and pressure from two different sensors are also provided. A quality control flag is associated with each scientific measurement. A flight flag is also included to indicate the different phases of the flight - on the ground, take-off/landing phases, and in flight. All the data have been synchronized and interpolated at 10 hertz (Hz). The purpose of this dataset is to provide information on albedo over different features of the sea ice (snow, melt pond, ocean). Three flight patterns were implemented during the campaign with the HELiX, a grid pattern at constant altitude (15 meters or 7 meters above ground level), hovering flights ( 2-5 minutes hovering over identified sea ice features at low altitude ~ 3 meters above ground level), and profiles up to 400 meters above ground level. Displaying latitude, longitude and altitude will help users to identify the flight pattern. Albedo measurements have been validated with surface-based measurements and details can be found in de Boer, G. R. Calmer, G. Jozef, J. Cassano, J. Hamilton, D. Lawrence, S. Borenstein, A. Doddi, C. Cox, J. Schmale, A. Preußer and B. Argrow (2021): Observing the Central Arctic Atmosphere and Surface with University of Colorado Uncrewed Aircraft Systems, Nature Scientific Data, in prep. 

A1 level data from HELiX Uncrewed Aircraft System correspond to the raw data collected in the Central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Synchronized and quality-controlled B1 level data are also available in the Arctic Data Center. Users are encouraged to primarily use the B1 level data for analysis. A1 level data include hemispheric irradiance measurements from Kipp and Zonen pyranometers and thermodynamic parameters from Vaisala RSS421 sensors. Autopilot positions and attitudes, along with gimbal attitudes are also provided. Each field of measurements has its own time stamped based on a common clock and associated acquisition frequency. No synchronization or Universal Coordinated Time (UTC) are provided at the A1 level. This dataset is used to create the B1 level data at 10 hertz (Hz) with quality-controlled flags. More information on the data and method can be found in de Boer, G. R. Calmer, G. Jozef, J. Cassano, J. Hamilton, D. Lawrence, S. Borenstein, A. Doddi, C. Cox, J. Schmale, A. Preußer and B. Argrow (2021): Observing the Central Arctic Atmosphere and Surface with University of Colorado Uncrewed Aircraft Systems, Nature Scientific Data, in prep.