Aerial Application Technology Research Session

Join us for the NAAA Ag Aviation Expo
November 18–21, 2019 ♦ Orlando, FL
​Rosen Shingle Creek

Note the November date for 2019


In-Wind and Crosswind Impacts on Swath Patterns
Bradley K. Fritz, USDA-ARS, College Station, TX
Evaluating the effective swath width and adjusting the deposition pattern for uniformity are critical to the efficacy of any given application. Adjusting nozzle placement to maximize pattern uniformity and width while minimizing droplet entrainment into the wing tip vortices is key to a successful application. While pattern testing on agricultural aircraft is typically done with the pilot flying into the wind to maximize spray deposition onto sampling media, the reality is pilots typically make applications in some degree of crosswind conditions. This crosswind has the effect of shifting the pattern in the downwind direction, offsetting the swath placement and potentially stacking up material on the upwind side creating non-uniform droplet size of the deposited material across the swath. This work examines the resulting characteristics from pattern testing trials under both in-wind and crosswind conditions, as well as examines the effect of adjusting nozzle positions on the outward edges of the spray boom. 
Dr. Fritz is an Agricultural Engineer with the USDA Agricultural Research Service, Aerial Application Technology Research Unit, a group tasked to research all aspects of aerial application technology. Dr. Fritz’s early research efforts centered on the role atmospheric conditions, such as stability and inversion, played in the movement and ultimate fate of aerially applied sprays with the goal of maximizing on-target deposition with minimal downwind loss. Current research focuses on the role nozzles and spray formulations play in the formation of droplet size and has led to development of new fixed and rotary-wing spray nozzle models and enhanced user interfaces for applicators. Dr. Fritz actively participates in a number of professional organizations and continues to regularly publish and present his research findings through a number of peer-reviewed journals and national and international meetings. 
Development of a System to Measure Dry Material Flow in Real-Time for Pattern Testing
Randy Price, LSU AgCenter, Alexandria, LA; Dan Martin, USDA-ARS, College Station, TX
Dry material pattern testing of aircraft is an important procedure in many states, and with the increased use of cover crops, other states (with low dry material application needs) are seeing a resurgence in this area. Still, most of the equipment used for dry material spreader pattern testing is based on setting up a series of dry collector bags—in a line—with individual collector vials that are collected and weighed after each run. This system is labor intensive to operate and can be physically demanding on the workers due to the repeated bending over to collect vials. For this reason, the LSU AgCenter and the USDA have been looking at methods to automate this procedure and develop a system that operates in real-time with accuracies that rival current weighing methods (0.01 grams). Current methods being tested are impact plates, miniature individual weigh scales per bag, depth of material per vial, and optical counting of material through an orifice (that simulates an “hour glass” type pour rate).
Dr. Price works for the LSU AgCenter where he is a statewide Agricultural Engineer in charge of pattern testing agricultural aircraft, maintaining the LAIS weather station system and developing new technologies for precision farming. He currently works at the Dean Lee Research and Extension office located in Alexandria, LA.
On-the-Fly Spray System Adjustments with Individual Nozzle Control
Russ Stocker, Aerial Applicator, Woodland, CA
Optimizing an aerial spray system’s performance is critical in managing deposition, increasing productivity and mitigating potential drift. Configuring a spray system is commonly a compromise between these goals and often, once a spray system is configured, it is not changed even though conditions change. A new system that allows electronic control of individual nozzles, from the cockpit, is now commercially available. The system was installed on a working aircraft and tested for swath optimization performance and ability to compensate for changing conditions. The ability of the pilot to alter the spray pattern, and to change rate, instantly, and from the cockpit, was proven.
Russ Stocker holds a B.S. Degree in Environmental Toxicology from the University of California at Davis. Russ has more than 46 years of experience in the aerial application industry, including over 25,000 hours as an ag pilot in both fixed-wing and rotor-wing aircraft. He has developed hands-on training programs for the California Department of Pesticide Regulation and EPA and participated in continuing education and research projects involving pesticide application for university, forestry, vector control and private industry including the Spray Drift Task Force. 
Field Evaluation of Commercially Available Small Unmanned Aircraft Crop Spray Systems
Wayne Woldt, University of Neb., Lincoln; Dan Martin, USDA-ARS, College Station, TX
Agricultural research and development of small unmanned aircraft systems (UAS) have been directed toward UAS-enabled sensing to detect features of interest. While compelling, there is an immediate need to increase the breadth and depth of UAS-based research, to move beyond sensing, and explore active intervention in agricultural production systems. This paper is focused on the concept of crop protection through ultra-precise Unmanned Aerial Application Systems and seeks to initiate research discussion in this important area of opportunity. Two commercially available small Unmanned Aerial Application Systems (sUAAS – defined as less than 55 lbs. maximum takeoff weight) were evaluated for operational techniques and application system efficacy under dynamic field conditions. The performance of the factory supplied spray systems are documented using traditional aerial spray testing methods that have been modified for sUAAS. Results from initial testing indicate that the different factory supplied systems resulted in significant differences in spray droplet spectra, deposition and effective spray swath. These unique differences between sUAAS highlight a very real need for the development of standardized sUAAS testing procedures.
Dr. Woldt is an Associate Professor and Extension Specialist at the University of Nebraska, in the Department of Biological Systems Engineering and the School of Natural Resources. He has been at UNL for 27 years and has developed a research and extension program on the application of unmanned aircraft systems. Wayne is the Director of the Nebraska Unmanned Aircraft Innovation, Research and Education (NU-AIRE) laboratory and his areas of interest include: agriculture, flight safety and land mapping. Specific areas of research and education include: small unmanned aerial application systems, development of a safety beacon for UAS flight operations, development of passive and active sensing technologies for agriculture and natural resources, deployment and flight operations of unmanned aircraft systems, and performance of autonomous navigation systems. Wayne has been flying unmanned aircraft for the past six years and obtained the first FAA issued Certificate of Authorization to fly unmanned aircraft in Nebraska. His pilot ratings include private, glider, hot air balloon and remote, with more than 700 hours of total flight time.
Development of an Optical Sensor System for Detection of Herbicide Spray Droplets
Y. Huang, W. Ma, K. Fisher; USDA-ARS, Stoneville, MS
Understanding the factors involved in herbicide spray drift and the magnitude each plays in the process is important when setting up spray systems to ensure effective crop production management and environmental protection. In this study, an optical sensor system was developed using a single broadband programmable LED light source and six broadband detectors at 610, 680, 730, 760, 810 and 860 nm, respectively, to build a monitoring and analysis system for herbicide spray droplets. A rotating system with a stepper motor was built to shift the monofilament line under the optical detectors to collect the signals resulting from the reflectance droplets along the line. To test the system, the LED light intensity was varied continuously. When spraying from a hand-held atomizer from 2 m away, the sensor system could identify small (Very Fine and Fine), medium (Medium) and large (Coarse) droplets. The results indicated that the system could determine the droplet position on the line with 100 percent accuracy without needing to use tracer dye. The wavelength of 610 nm was selected as the best among the six bands to detect the droplet sizes. This system has a great potential to aid researchers in better understanding the processes involved in the deposition and transport of aerially sprays. 
Dr. Huang is an Agricultural Engineer with the USDA-ARS Crop Production Systems Research Unit in Stoneville, MS. His research interests include aerial application (piloted and unmanned); remote sensing for precision application (space-borne, airborne and ground truthing); soft computing and decision support for precision agriculture; spatial statistics for remote sensing data analysis; and image processing and process automation. Dr. Huang has authored or co-authored numerous peer-reviewed papers and is an active member of several national and international professional organizations. 
Remote Sensing Platforms and Imaging Systems for Agricultural Applications
Chenghai Yang, USDA-ARS, College Station, TX 
Over the last two decades, numerous commercial and custom-built airborne and high-resolution satellite imaging systems have been developed and deployed for diverse remote sensing applications. While unmanned aircraft systems (UAS) have recently emerged as potential low-cost platforms for remote sensing, they are limited by FAA’s 400-foot flight ceiling, slower speeds, short battery life and smaller payloads. Moreover, the safety concerns of commercial pilots, in particular aerial applicators and other pilots operating in low-level airspace, need to be addressed before the widespread use of UAS for commercial imaging. This presentation will provide a brief overview of different satellite and airborne remote sensing platforms and imaging systems. Practical application examples will be provided on the use of consumer-grade cameras mounted on agricultural aircraft for precision agriculture and pest management.
Dr. Yang is an Agricultural Engineer with the USDA-ARS Aerial Application Technology Research Unit in College Station, TX. Dr. Yang’s research focuses on the development and application of airborne multispectral, hyperspectral and thermal imaging systems for precision agriculture and pest management. His recent efforts have focused on developing low-cost imaging systems and image processing techniques for aerial applicators and evaluating these systems for mapping crop pests for site-specific chemical applications. He has authored or co-authored more than 140 peer-reviewed journal articles and serves on a number of national and international professional societies.
Effective Swath, Pattern Uniformity and Spray Droplet Spectra from Manned and Unmanned Rotary Wing Aircraft
Dan Martin, USDA-ARS, College Station, TX
Rotary-wing aircraft have been used as aerial application platforms for decades. They allow applicators access to difficult-to-reach areas and where dangerous obstacles require slower airspeeds with increased maneuverability. Recently, in addition to manned single-rotor aircraft, unmanned multi-rotor aerial application platforms have become commercially available and are being used worldwide. With these new units come new questions. How productive are they, how safe are they, how fast can they fly, how long can they stay in the air, how much payload can they carry, what does the spray pattern look like, how wide is their swath, etc.? In this study, we look at the effect of application height and ground speed on the effective swath, pattern uniformity and spray droplet spectra from a Robinson R-44 Raven II and an HSE M6E UAS spray system. We will answer the questions above, which will raise additional questions.
Dr. Martin is a Research Agricultural Engineer with the USDA-ARS Aerial Application Technology Research Unit in College Station, TX. Prior to his tenure with ARS, he directed the aerial application extension program in Louisiana for 10 years, working one on one with aerial applicators as an Operation S.A.F.E. Analyst and Extension Educator. Currently, he conducts variable rate and electrostatic aerial application research. He is an active member of several professional societies, serves on several technical committees and has authored numerous refereed publications.
Incorporation of Risk into AgSync: How Risk Affects Your Bottom Line
Sam Dharmasena, Texas A&M University, College Station, TX; David Eby, AeroFlow Systems, Wakarusa, IN; Dan Martin, USDA-ARS, College Station, TX
Aerial applicators have always had to deal with hazards such as tree lines, powerlines, concerned neighbors and low-altitude flying at high speeds. Over the past several years, those hazards have steadily increased. We now commonly have wind turbines, organic crops and houses in the middle production fields. Applicators have always charged “per acre,” but is the risk involved in spraying an acre of corn among a thousand more acres of corn the same as the risk for spraying that same acre right next to an elementary school? It’s a rhetorical question. That extra risk is going to cost the applicator (and the industry) something extra, whether it is a loss of productivity while waiting for the right wind, a drift claim or poor public relations. The PAASS Program teaches us, “Upon the performance of each rests the fate of all.” So how do we account for this extra risk we take upon ourselves? This talk discusses those risks and shows how they have been incorporated into AgSync to allow aerial applicators to be adequately compensated. 
Dr. Dharmasena is Assistant Professor, Department of Agricultural Economics, Texas A&M University. Dr. Dharmasena’s current research interests are in the areas of Consumer Economics and Applied Demand Analysis, Agribusiness and Food Market Analysis, Behavioral Economics, Health and Nutrition Economics, Economics of Food Security, Food Environments and Obesity, Causality Modeling, Probability Forecasting and Forecast Evaluation, and Market Integration and Price Discovery. He is an expert in applied econometric modeling and has published in leading peer-reviewed journals. He is member of several national and international professional associations.

Didn't make it to a previous NAAA Ag Aviation Expo? Click the links below to review the previous Aerial Application Technical Session Presentations.