Aerial Application Technology Research Session

NAAA Ag Aviation Expo
December 5–8, 2022 ♦ Knoxville, TN 
NAAA’s educational programming leads off with the Aerial Application Technology Research Session, led by aerial application researchers, possibly one of the convention’s most substantive sessions. This year’s session will cover several “new” tools and information ready to use as part of your everyday operations. Researchers have been working on most of these projects over the past several years and are eager to help make your applications more efficacious, make you an even better environmental steward and your application business more cutting-edge. Several states offer CEU credits for this session; be sure to sign in at the entranceway. 

2022 Aerial Application Technology Research Presentations will be online in Sept. 2022

2021 Aerial Application Technology Research Presentations

Evaluation of light sport aircraft as an aerial imaging platform

Chenghai Yang and Jonathan T. Scott
Remote sensing data are generally obtained using three major types of platforms: satellites, manned aircraft, and unmanned aircraft systems (UAS). Compared with satellites and UAS, manned aircraft are more versatile to capture images with desired coverage and resolution. Light sport aircraft (LSA) are a fairly new certification of small, lightweight aircraft defined by a maximum takeoff weight of 1,300 pounds (600 kilos). They can be markedly less expensive than larger manned aircraft. LSA therefore have the potential to be a flexible, versatile and economical platform for aerial imaging. In collaboration with the Circular Economy Research Center (CERC) at Ecole des Ponts Paris Tech, we evaluated the feasibility, performance, and economics of using LSA as aerial imaging platforms. Our flight tests included an all-metal fixed-wing aircraft (Colt-100), a composite-based, fixed-wing motor-glider (Pipistrel Sinus) and a composite-based gyroplane (Magni M24). Each aircraft was equipped with a two-camera system and flew an identical 30,000-acre cropping area in June 2021. Preliminary results showed that all three LSA feasibly carried the imaging system, successfully flew over the predetermined flight lines, and efficiently collected the required images. Economic and material analysis results are currently being collected and reviewed to determine the strengths and weaknesses associated with using LSA in imaging work. It is important to note that the FAA is expected to authorize commercial use of LSA sometime in 2023, so it is conceivable that LSA can be integrated into the aerial application industry as an alternative, affordable, and less-polluting, aerial-imaging platform.
Bio: Dr. Chenghai Yang is a Research 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 remote sensing technologies 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 assessing crop conditions for site-specific chemical applications. Dr. Yang has authored or co-authored 160 peer-reviewed journal articles and serves on a number of national and international professional societies.

Simulating Reality-Using CFD to Simulate Spray Nozzles

Sam Marx

There are a wide range of nozzle types, nozzle flow rates, and droplets produced by those nozzles.  Many nozzles are made using empirical evidence and testing physical models to determine how that nozzle performs.  By using computational fluid dynamics (CFD), nozzle geometry can be modeled, and the atomization process can be simulated numerically.  Using CFD to simulate nozzles may allow for faster development of future nozzles and/or attempting nozzle geometries that are not common manufacturing practice.  This presentation will introduce the audience to how simulation might be beneficial for nozzle development as well as some examples of current nozzle geometries being simulated. 

Bio: Sam Marx is currently a Research Technologist for the Biological Systems Engineering Department at the University of Nebraska-Lincoln. He is simultaneously pursuing his PhD in Agricultural and Biological Systems Engineering at UNL. His current research includes aerial nozzle development using computational fluid dynamic modeling as well as other ground based and UAV precision application technologies. Sam has a history in the agricultural engineering industry working on development, testing and production of agricultural application systems, including aerial application equipment. Sam is an active member of ASABE where he is Chair of the MS-23/6/2 Aerial Application Standards and Safety Committee and former Vice Chair of the MS-23/6/5 Anhydrous Ammonia Application Standards and Safety Committee.  

Effects of Pulse Width Modulation Nozzles on Droplet Size and Flow Rate

Dr. Brad Fritz

The ability to control spray application rate during flight is becoming more critical as the need to address the demand for precision applications increases.  While flow control systems have been commercially available and in use for some time, most alter flow through changes in spray pressure, which has the additional effect of altering droplet size.  The use of pulse width modulation (PWM) valves offer the benefit of modifying pressure while maintaining droplet size from the nozzle.  While some limited testing of these systems has been completed, there is a need for more rigorous testing and development of PWM specific droplet size models for the nozzles integrated into these systems.  This provides more accurate data that can be integrated into the decision support software of current systems.  A commercially available PWM system was evaluated for droplet size and flowrates for several commonly used aerial nozzles covering a range of airspeeds and pressures.  Further, droplet sizing models were developed that incorporated PWM duty cycle as a parameter in addition to airspeed, pressure, orifice size and orientation angle.

Bio: Dr. Brad Fritz is an agricultural engineer and serves as the Research Leader of the USDA ARS Aerial Application Technology Unit in College Station, Texas.  His areas of research include spray drift measurement and methods of mitigation, understanding the role spray nozzles and formulations play in the droplet size being applied and optimizing aerial application technologies and methods to enhance on target deposition and reduce off-target impacts.  He is an active member of a number of professional organizations including the American Society of Agricultural and Biological Engineers, the American Society of Testing and Materials, the American Mosquito Control Association, and the National Agricultural Aviation Association.  

Value of the Agricultural Aerial Application Industry in the United States

Senarath Dharmasena, PhD. and Daniel E. Martin, PhD. 
Aerial application is a very critical component of high-yielding and highly efficient current-day U.S. agriculture. This industry is important to aerial applicators, farmers and ranchers, and consumers of the food, fiber and forestry products. Furthermore, given the current global health crisis related to COVID-19 pandemic, the importance of this industry to keep a continuous supply of agricultural products to the U.S. economy is further highlighted. Dharmasena and Martin (2020) estimated the value of the agricultural aerial application industry based on the revenue forgone by the U.S. farmers. However, this study only considered selected crops (such as corn for grain, wheat, cotton, soybeans, rice ) grown in the United States and the state of Texas to estimate the value of the agricultural aerial application industry only considering the lost revenue at the farm-gate level. Given the complexity of the agricultural value channel with multiple players such as input suppliers, farmers, processors (includes transportation, storage, processing), wholesales, and retailers, the revenue losses estimated by Dharmasena and Martin (2020) can be expanded to include all participants in the agricultural value channel. In addition to that, the crops and forestry products grown vary across states of the United States and due to that the revenue forgone will also differ based on the agricultural practice. In this study, data from National Agricultural Aviation Association and the USDA Economic Research Service is used to develop an economic model using cutting-edge econometric tools to estimate the value of the aerial application industry to the United States economy delineated by different crops/forestry products and states, and different stages of the agricultural value channel.
Bio: Dr. Dharmasena is Associate Professor, Department of Agricultural Economics, Texas A&M University.  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, both structural and time-series. He is member of several national and international professional associations and is Fellow of Critical Thinking Academy of Texas A&M University. 

Development of Analysis Equipment for Pattern Testing Agricultural Aircraft

Randy Price, Daniel Martin, and Kim Brown
Pattern testing of agricultural aircraft is an important feature to maintain consistent spray patterns and low coefficients of variation (C.V.).  Still, most pattern testing equipment requires multiple people to operate and store the pattern test strings on reels, which can greatly limit the number and the amount of test you can perform. Work has been performed on a system to increase the number of tests that can be performed per flight and even allows full-field testing. This system uses a GoPro camera and green laser system mounted at the collection-end of the flight-line to analyze the strings as it is “pulled-in” from the flight-line for reflectance patterns.  This system was successfully used during the 2020 season and greatly reduced the number of people needed to operate the flight-line and the work involved in collecting strings allowing for one person to perform tests on many occasions. It was also successfully used to perform multi-pass, large field scale tests, where swath predictions can be checked and verified to help instill confidence in swath width recommendations to spray plane pilots and operators. This presentation will talk about this system, testing methods, and results from these tests.  
Bio: Dr. Randy Price is an Associate Professor at the LSU AgCenter, Baton Rouge, Louisiana.  He continually works on new equipment and methods to help the agricultural spray plane industry and is a certified Operation S.A.F.E. analyst.

Effect of Application Rate on Fungicide Efficacy from an Aerial Application for Control of Sheath Blight in Rice

Daniel E. Martin, Chenghai Yang, Xin-Gen Zhou, Randy Price, Bradley Reed
Ever wondered if putting out a product at 2 GPA could work just as well as an application at 5 GPA? Applications at lower volumes not only save time and money, but also can make aerial applications timelier so that pests are controlled before they can do additional damage. The objective of this study was to determine if lower application rates of fungicide for control of sheath blight in rice can be just as effective as higher application rates. Aerial applications were made at 2 and 6 GPA. Efficacy of disease control was evaluated by plant pathologists at the Texas A&M AgriLife Research Station in Beaumont, Texas. In addition, aerial images were taken of the field, before and after treatment, to assess control. Results of the study will be presented and discussed.

Bio: Dr. Martin is a Research Agricultural Engineer with the USDA-ARS Aerial Application Technology Research Unit and has over 30 years of training and experience in aerial spray application technologies for precision agriculture. He has authored/coauthored over 50 journal articles and has given over 100 technical presentations at regional, national, and international forums. He has held various leadership positions in professional societies and is recognized as a leading authority in manned and unmanned aerial application systems for precision agriculture and pest management. 

Developing a High Pressure, Modular Chemical Delivery System for Aerial Application Platforms

Mark Ledebuhr, Nick Tipper, PE and Sarah Ziehm

The aerial application community has known for many years that higher spray pressure reduces the droplet size on aerial sprays, especially in straight streams. To date, there are few options to do this practically. A novel system was developed to create high pressure flows under conditions required by Aerial applicators. The result is a cartridge-based, DC drive system capable of variable pressure up to 150 PSI. The system is valveless, faster than current valving, and replaces the suck-back feature in current bypass valves. This presentation will discuss the development, results and future steps on this project. 


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