Implementation and improvement of an unmanned aircraft system for precision farming purposes

Precision farming (PF) is an agricultural concept that accounts for within-field variability by gathering spatial and temporal information with modern sensing technology and performs variable and targeted treatments on a smaller scale than field scale. PF research quickly recognized the possible benefits unmanned aerial vehicles (UAVs) can add to the site-specific management of farms. As UAVs are flexible carrier platforms, they can be equipped with a range of different sensing devices and used in a variety of close-range remote sensing scenarios. Most frequently, UAVs are utilized to gather actual in-season canopy information with imaging sensors that are sensitive to reflected electro-magnetic radiation in the visual (VIS) and near-infrared (NIR) spectrum. They are generally used to infer the crops biophysical and biochemical parameters to support farm management decisions. A current disadvantage of UAVs is that they are not designed to interact with their attached sensor payload. This leads to the need of intensive data post-processing and prohibits the possibility of real-time scenarios, in which UAVs can directly transfer information to field machinery or robots. In consequence, this thesis focused on the development of a smart unmanned aircraft system (UAS), which in the thesis context was regarded as a combination of a UAV carrier platform, an on-board central processing unit for sensor control and data processing, and a remotely connected ground control station. The ground control station was supposed to feature the possibility of flight mission control and the standardized distribution of sensor data with a sensor data infrastructure, serving as a data basis for a farm management information system (FMIS). The UAS was intended to be operated as a flexible monitoring tool for in-season above-ground biomass and nitrogen content estimation as well as crop yield prediction. Therefore, the selection, development, and validation of appropriate imaging sensors and processing routines were key parts to prove the UAS usability in PF scenarios. The individual objectives were (i) to implement an advanced UAV for PF research, providing the possibilities of remotely-controlled and automatic flight mission execution, (ii) to improve the developed UAV to a UAS by implementing sensor control, data processing and communication functionalities, (iii) to select and develop appropriate sensor systems for yield prediction and nitrogen fertilization strategies, (iv) to integrate the sensor systems into the UAS and to test the performance in example use cases, and (v) to embed the UAS into a standardized sensor data infrastructure for data storage and usage in PF applications. This work demonstrated the successful development of a custom rotary-wing UAV carrier platform with an embedded central processing unit. A modular software framework was developed with the ability to control any kind of sensor payload in real-time. The sensors can be triggered and their measurements are retrieved, fused together with the carriers navigation information, logged and broadcasted to a ground control station. The setup was used as basis for further research, focusing on information generation by sophisticated data processing. For a first application of predicting the grain yield of corn (Zea mays L.), a simple RGB camera was selected to acquire a set of aerial imagery of early- and mid-season corn crops. Orthoimages were processed with different ground resolutions and were computed to simple vegetation indices (VI) for a crop/non-crop classification. In addition to that, crop surface models (CSMs) were generated to estimate the crop heights. Linear regressions were performed with the corn grain yield as dependent variable and crop height and crop coverage as independent variable. The analysis showed the best prediction results of a relative root mean square error (RMSE) of 8.8 % at mid-season growth stages and ground resolutions of 4 cm px −1 . Moreover, the results indicate that with on-going canopy closure and homogeneity accounting for high ground resolutions and crop/non-crop classification becomes less and less important. For the estimation of above-ground biomass and nitrogen content in winter wheat (Triticum aestivum L.) a programmable multispectral camera was developed. It is based on an industrial multi-sensor camera, which was equipped with bandpass filters to measure four narrow wavelength bands in the so-called red-edge region. This region is the transition zone in between the VIS and NIR spectrum and known to be sensitive to leaf chlorophyll content and the structural state of the plant. It is often used to estimate biomass and nitrogen content with the help of the normalized difference vegetation index (NDVI) and the red-edge inflection point (REIP). The camera system was designed to measure ambient light conditions during the flight mission to set appropriate image acquisition times, which guarantee images with high contrast. It is fully programmable and can be further developed to a real-time image processing system. The analysis relies on semi-automatic orthoimage processing. The NDVI orthoimages were analyzed for the correlation with biomass by means of simple linear regression. These models proved to estimate biomass for all measurements with RMSEs of 12.3 % to 17.6 %. The REIP was used to infer nitrogen content and showed good results with RMSEs of 7.6 % to 11.7 %. Both NDVI and REIP were also tested for the in-season grain yield prediction ability (RMSE = 9.012.1 %), whereas grain protein content could be modeled with the REIP, except for low-fertilized wheat plots. The last part of the thesis comprised the development of a standardized sensor data infrastructure as a first step to a holistic farm management. The UAS was integrated into a real-time sensor data acquisition network with standardized data base storage capabilities. The infrastructure was based on open source software and the geo-data standards of the Open Geospatial Consortium (OGC). A prototype implementation was tested for four exemplary sensor systems and proved to be able to acquire, log, visualize and store the sensor data in a standardized data base via a sensor observation service on-the-fly. The setup is scalable to scenarios, where a multitude of sensors, data bases, and web services interact with each other to exchange and process data. This thesis demonstrates the successful prototype implementation of a smart UAS and a sensor data infrastructure, which offers real-time data processing functionality. The UAS is equipped with appropriate sensor systems for agricultural crop monitoring and has the potential to be used in real-world scenarios.Precision farming (PF) ist ein landwirtschaftliches Konzept, das die Variabilität innerhalb eines Feldes berücksichtigt, indem es mit Hilfe moderner Sensortechnologien räumliche und zeitliche Bestandsinformationen sammelt. Dadurch ist PF in der Lage, gezielte teilflächenspezifische Anwendungen innerhalb eines Feldes durchzuführen. Die Forschung im Bereich von PF hat früh die potenziellen Vorzüge von kleinen Luftfahrzeugen, sogenannten unmanned aerial vehicles (UAVs), für die teilflächenspezifische Bewirtschaftung erkannt. Da UAVs flexible Lastenträger darstellen, können sie mit den verschiedensten Sensoren ausgestattet und in einer Vielzahl von fernerkundlichen Anwendungsfällen in der Landwirtschaft genutzt werden. Dabei werden sie am häufigsten mit bildgebenden Sensoren eingesetzt, um aktuelle Informationen über den Pflanzenbestand in der Vegetationsperiode zu liefern. Die eingesetzten Sensoren sind dabei meist zur Messung elektromagnetischer Strahlung im sichtbaren (VIS) und nahen infraroten (NIR) Bereich ausgelegt. Im Allgemeinen werden sie dazu benutzt auf biophysikalische und biochemische Eigenschaften der Nutzpflanzen zu schließen und damit die Entscheidungsprozesse in der Bestandsführung zu unterstützen. Ein aktueller Nachteil der UAVs ist, dass sie nicht dafür gebaut werden um mit ihrer Nutzlast zu interagieren. Das führt zu einem Bedarf an erheblicher Datennachverarbeitung und verhindert Echtzeitszenarios, in denen UAVs Informationen direkt an Feldmaschinen und Roboter senden können. Aus diesem Grund konzentrierte sich diese Dissertation auf die Entwicklung eines intelligenten fliegenden Systems, eines sogenannten unmanned aircraft system (UAS), welches im Kontext dieser Dissertation als eine Kombination aus UAV Trägerplattform, zentralem Computer zur Sensorsteuerung und Datenverarbeitung, sowie einer entfernt verbundenen Bodenstation betrachtet wurde. Die Bodenstation war zur Flugüberwachung und zur standardisierten Verteilung der Sensordaten über eine Sensordateninfrastruktur bestimmt. Die Sensordateninfrastruktur diente als Basis eines sogenannten farm management information system (FMIS), das die Verwaltung und Bewirtschaftung eines landwirtschaftlichen Betriebs mit Methoden der Informatik unterstützt. Das UAS sollte als flexibles Aufklärungswerkzeug eingesetzt werden, um Schätzungen von Biomasse, Stickstoffgehalt und erwartetem Ertrag während der Vegetationsperiode zu liefern. Daher war die Auswahl, Entwicklung und Validierung geeigneter bildgebender Sensoren und zugehöriger Verarbeitungsmethoden ein zentraler Bestandteil, um die Nutzbarkeit von UAS im PF zu belegen. Die einzelnen Ziele waren (i) der Aufbau eines UAVs für das PF, das sich fernsteuern und automatisch nach Wegpunkten fliegen lässt, (ii) die Erweiterung des UAVs zum UAS, durch die Entwicklung einer zentralen Sensorsteuerung, Datenverarbeitung und Kommunikationsfähigkeit, (iii) die Auswahl und Entwicklung geeigneter Sensorsysteme zur Ertragsschätzung und Stickstoffdüngung, (iv) der Einbau der Sensorsysteme in das UAS und deren Validierung in Beispielanwendungen und (v) die Integration des UAS in eine standardisierte Sensordateninfrastruktur um die Daten für PF-Anwendungen abzuspeichern und verfügbar zu machen. Diese Dissertation präsentiert eine erfolgreiche Entwicklung eines Drehflügler-UAVs mit zentraler Steuereinheit. Dazu passend wurde eine modulare Software entwickelt, die jegliche Sensorik in Echtzeit steuern kann. Messungen können ausgelöst, empfangen, mit den Navigationsdaten des UAVs fusioniert, gespeichert und an eine Bodenstation gesendet werden. Das UAV diente als Basis weiterer Forschung, die die Verarbeitung von Sensordaten zur Erzeugung pflanzenbaulicher Information zum Ziel hatte. Eine erste Anwendung war die Ertragsschätzung von Körnermais (Zea mays L.). Eine einfache RGB Kamera wurde dazu benutzt Luftbilder von Maispflanzen in frühen und mittleren Wachstumsstadien aufzunehmen. Daraus wurden Orthophotos mit unterschiedlichen Bodenauflösungen erzeugt und zu einfachen Vegetationsindizes (VIs) zur Klassifizierung der Pixel als Pflanze oder nicht Pflanze weiterverarbeitet. Zusätzlich wurden Oberflächenmodelle des Pflanzenbestands, sogenannte crop surface models (CSMs), erzeugt, um die Pflanzenhöhen abzuschätzen. Mit dem Ertrag als abhängige Variable, sowie Pflanzenhöhe und Bedeckungsgrad als unabhängige Variablen, wurden lineare Regressionen durchgeführt. Die Analyse ergab beste Vorhersagen mit geringsten Standardabweichungen (SD) von 8.8 % für die Messungen in mittleren Wachstumsstadien mit einer Bodenauflösung von 4 cm px −1 . Darüber hinaus zeigten die Ergebnisse, dass hohe Bodenauflösungen und Klassifizierung mit fortschreitendem Reihenschluss und sich angleichendem Pflanzenbestand immer unwichtiger werden. Zur Schätzung von Biomasse und Stickstoffgehalt von Winterweizen (Triticum aestivum L.) wurde eine programmierbare multispektrale Kamera entwickelt. Sie basiert auf einer Industriekamera mit mehreren Sensorköpfen, von denen jeder mit einem Bandpassfilter bestückt wurde. Die Kamera misst vier schmalbandige Wellenlängen im Übergangsbereich vom VIS- zum NIR-Spektrum, der sogenannten roten Kante red-edge. Dieser Bereich ist dafür bekannt Rückschlüsse auf den Chlorophyllgehalt der Blätter und die Pflanzenstruktur zuzulassen. Mit Hilfe der Formeln zur Berechnung des normalized difference vegetation index (NDVI) und des red-edge inflection point (REIP) wird dieser Bereich oft zur Schätzung von Biomasse und Stickstoffgehalt genutzt. Das Kamerasystem wurde darüber hinaus entworfen, die Lichtverhältnisse während des Fluges zu messen und geeignete Belichtungszeiten festzulegen, um Bilder mit hohem Kontrast zu erzeugen. Die Kamera ist komplett programmierbar und kann zur Echtzeitbildverarbeitung weiterentwickelt werden. Die Untersuchung basiert auf der teilautomatisierten Erzeugung von Orthophotos. Die NDVI Orthophotos wurden mit Hilfe einer einfachen linearen Regression auf ihre Korrelation mit Biomasse getestet. Sie zeigten über alle Messzeitpunkte, dass sie Biomasse mit Standardabweichungen von 12.3 % bis 17.6 % schätzen konnten. Der REIP wurde zur Stickstoffgehaltschätzung heran gezogen und zeigte gute Ergebnisse mit Standardabweichungen von 7.6 % bis 11.7 %. Beide, NDVI und REIP, wurden auch auf ihre Vorhersagefähigkeit des Kornertrags getestet (SD = 9.012.1 %). Überdies konnte, außer in gering gedüngten Parzellen, der Proteingehalt im Korn mit dem REIP abgeschätzt werden. Der letzte Teil der Dissertation beinhaltete die Entwicklung einer standardisierten Sensordateninfrastruktur als Schritt hin zu einem umfassenden Bewirtschaftungskonzept, das möglichst viele Faktoren berücksichtigt. Das UAS wurde in ein echtzeitbasiertes Sensordatennetzwerk integriert, das Sensordaten erfassen und standardisiert in Datenbanken ablegen kann. Die Infrastruktur basiert auf quellcodeoffener open source software und den Geodatenstandards des Open Geospatial Consortiums (OGC). Eine erste Umsetzung einer solchen Infrastruktur wurde mit vier Beispielsensoren getestet und zeigte, dass Sensordaten in Echtzeit erfasst, lokal gespeichert, visualisiert und mittels eines Sensordatendienstes (sensor observation service) standardisiert in einer Datenbank gespeichert werden konnten. Die Umsetzung ist auf eine beliebige Anzahl von Sensoren und Diensten erweiterbar und ermöglicht ihnen den Austausch und die Verarbeitung von Daten. Diese Dissertation zeigt eine erfolgreiche Umsetzung eines intelligenten UAS und einer Sensordateninfrastruktur, die Sensordatenverarbeitung in Echtzeit anbietet. Das UAS ist mit Sensoren ausgestattet, die zur landwirtschaftlichen Beurteilung von Pflanzenbeständen geeignet sind und zeigt Potential auch unter realistischen Bedingungen eingesetzt werden zu können

Uumanned Aerial Vehicle Data Analysis For High-throughput Plant Phenotyping

The continuing population is placing unprecedented demands on worldwide crop yield production and quality. Improving genomic selection for breeding process is one essential aspect for solving this dilemma. Benefitted from the advances in high-throughput genotyping, researchers already gained better understanding of genetic traits. However, given the comparatively lower efficiency in current phenotyping technique, the significance of phenotypic traits has still not fully exploited in genomic selection. Therefore, improving HTPP efficiency has become an urgent task for researchers. As one of the platforms utilized for collecting HTPP data, unmanned aerial vehicle (UAV) allows high quality data to be collected within short time and by less labor. There are currently many options for customized UAV system on market; however, data analysis efficiency is still one limitation for the fully implementation of HTPP. To this end, the focus of this program was data analysis of UAV acquired data. The specific objectives were two-fold, one was to investigate statistical correlations between UAV derived phenotypic traits and manually measured sorghum biomass, nitrogen and chlorophyll content. Another was to conduct variable selection on the phenotypic parameters calculated from UAV derived vegetation index (VI) and plant height maps, aiming to find out the principal parameters that contribute most in explaining winter wheat grain yield. Corresponding, two studies were carried out. Good correlations between UAV-derived VI/plant height and sorghum biomass/nitrogen/chlorophyll in the first study suggested that UAV-based HTPP has great potential in facilitating genetic improvement. For the second study, variable selection results from the single-year data showed that plant height related parameters, especially from later season, contributed more in explaining grain yield. Advisor: Yeyin Sh

A Decade of Unmanned Aerial Systems in Irrigated Agriculture in the Western U.S.

Several research institutes, laboratories, academic programs, and service companies around the United States have been developing programs to utilize small unmanned aerial systems (sUAS) as an instrument to improve the efficiency of in-field water and agronomical management. This article describes a decade of efforts on research and development efforts focused on UAS technologies and methodologies developed for irrigation management, including the evolution of aircraft and sensors in contrast to data from satellites. Federal Aviation Administration (FAA) regulations for UAS operation in agriculture have been synthesized along with proposed modifications to enhance UAS contributions to irrigated agriculture. Although it is feasible to use sUAS technology to produce maps of actual crop coefficients, actual crop evapotranspiration, and soil water deficits, for irrigation management, the technology and regulations need to evolve further to facilitate a successful wide adoption and application. Improvements and standards are needed in terms of cameras’ spectral (bands) ranges, radiometric resolutions and associated calibrations, fuel/power technology for longer missions, better imagery processing software, and easier FAA approval of higher altitudes flight missions among other issues. Furthermore, the sUAS technology would play a larger role in irrigated agriculture when integrating multi-scale data (sUAS, groundbased or proximal, satellite) and soil water sensors is addressed, including the need for advances on processing large amounts of data from multiple and different sources, and integration into scientific irrigation scheduling (SIS) systems for convenience of decision making. Desirable technological innovations, and features of the next generation of UAS platforms, sensors, software, and methods for irrigated agriculture, are discussed

Elucidating Sorghum Biomass, Nitrogen and Chlorophyll Contents With Spectral and Morphological Traits Derived From Unmanned Aircraft System

Unmanned aircraft systems (UAS) provide an efficient way to phenotype cropmorphology with spectral traits such as plant height, canopy cover and various vegetation indices (VIs) providing information to elucidate genotypic responses to the environment. In this study, we investigated the potential use of UAS-derived traits to elucidate biomass, nitrogen and chlorophyll content in sorghum under nitrogen stress treatments. A nitrogen stress trial located in Nebraska, USA, contained 24 different sorghum lines, 2 nitrogen treatments and 8 replications, for a total of 384 plots. Morphological and spectral traits including plant height, canopy cover and various VIs were derived from UAS flights with a true-color RGB camera and a 5-band multispectral camera at early, mid and late growth stages across the sorghum growing season in 2017. Simple and multiple regression models were investigated for sorghum biomass, nitrogen and chlorophyll content estimations using the derived morphological and spectral traits along with manual ground truthed measurements. Results showed that, the UAS-derived plant height was strongly correlated with manually measured plant height (r = 0.85); and the UAS-derived biomass using plant height, canopy cover and VIs had strong exponential correlations with the sampled biomass of fresh stalks and leaves (maximum r = 0.85) and the biomass of dry stalks and leaves (maximum r = 0.88). The UAS-derived VIs were moderately correlated with the laboratory measured leaf nitrogen content (r = 0.52) and the measured leaf chlorophyll content (r = 0.69) in each plot. The methods developed in this study will facilitate genetic improvement and agronomic studies that require assessment of stress responses in large-scale field trials

Automatic Identification and Monitoring of Plant Diseases Using Unmanned Aerial Vehicles: A Review

Disease diagnosis is one of the major tasks for increasing food production in agriculture. Although precision agriculture (PA) takes less time and provides a more precise application of agricultural activities, the detection of disease using an Unmanned Aerial System (UAS) is a challenging task. Several Unmanned Aerial Vehicles (UAVs) and sensors have been used for this purpose. The UAVs’ platforms and their peripherals have their own limitations in accurately diagnosing plant diseases. Several types of image processing software are available for vignetting and orthorectification. The training and validation of datasets are important characteristics of data analysis. Currently, different algorithms and architectures of machine learning models are used to classify and detect plant diseases. These models help in image segmentation and feature extractions to interpret results. Researchers also use the values of vegetative indices, such as Normalized Difference Vegetative Index (NDVI), Crop Water Stress Index (CWSI), etc., acquired from different multispectral and hyperspectral sensors to fit into the statistical models to deliver results. There are still various drifts in the automatic detection of plant diseases as imaging sensors are limited by their own spectral bandwidth, resolution, background noise of the image, etc. The future of crop health monitoring using UAVs should include a gimble consisting of multiple sensors, large datasets for training and validation, the development of site-specific irradiance systems, and so on. This review briefly highlights the advantages of automatic detection of plant diseases to the growers

Aquisição de informações em nível de campo da cana-de-açúcar utilizando dados de um veículo aéreo não tripulado (VANT) sob diferentes metodologias

Orientadores: Rubens Augusto Camargo Lamparelli, Jansle Vieira RochaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia AgrícolaResumo: A aplicação do sensoriamento remoto como ferramenta na agricultura de precisão, tornou-se cada vez mais comum devido à sua capacidade de fornecer informações espacialmente e temporalmente distribuídas. Neste contexto, o sensoriamento remoto de baixa altitude é um conceito relativamente novo para a aquisição de imagens. Sensores colocados em um Veículo Aéreo Não Tripulado (VANT) podem fornecer dados que atendam especialmente os requisitos críticos de resolução espacial e temporal para aplicações agrícolas. Portanto, uma produção agrícola de importância econômica, ambiental e energética, como a cana-de-açúcar, pode se beneficiar de informações fornecidas por esta tecnologia. Assim, o principal objetivo deste trabalho foi explorar as potencialidades e limitações do uso de um VANT no monitoramento da cana-de-açúcar. Através do desenvolvimento de metodologias para utilizar os dados de VANT, foi extraído informações qualitativas e quantitativas e comparamos com referências de campo e de satélite, para verificar a hipótese do estudo. Dessa maneira, a primeira parte desta tese, descreve um processo de análise de imagens orientada a objetos (OBIA) para imagens VANT, projetado para mapear e extrair informações sobre falhas em linhas de plantio de cana-de-açúcar. O método obteve bons resultados com uma relação entre as falhas estimadas e observadas de 97%. A segunda parte descreve a geração de modelos de superfície da cultura (MSC) derivadas das imagens de alta resolução do VANT para a estimativa de altura em canaviais. Além disso, foi investigada a influência de diferentes linhas de voo sobre a estimativa de altura e sua precisão, comparando os mapas gerados com as referências terrestres. Este método mostrou-se ideal para estimar a altura média de um talhão de cana-de-açúcar, em vez de realizar medidas pontuais em campo. Na terceira parte, os dados do VANT (RGB) e os dados de satélite (multiespectral, WorldView-2) foram analisados, a fim de avaliar a capacidade de cada sistema em representar a variabilidade dentro do talhão da produtividade da cana-de-açúcar estimada em campo. Os resultados mostraram que os dados de VANT produziram erros médios semelhantes, mas com poder de explicação inferior em comparação os dados do WorldView-2. Além disso, a incorporação de ambos os dados (WorldView-2 + VANT) melhorou a precisão. Em resumo, foi concluído que um sistema VANT é capaz de fornecer dados úteis de apoio a tomada de decisão para a produção de cana-de-açúcar. Essas plataformas tem a capacidade de fornecer imagens de alta resolução no momento ideal de aquisiçãoAbstract: The application of remote sensing as tool in precision agriculture has become increasingly common due to its ability to provide spatially and temporally distributed information. In this context, low-altitude remote sensing is a relatively new concept for the acquisition of images. Sensors placed on an unmanned aerial vehicle (UAV) can provide data that attend especially to the critical requirements of spatial and temporal resolution for agricultural applications. Therefore, crop production with economic, environmental and energy importance, such as sugarcane, can benefit from the information provided by this technology. Thus, the main objective of this research was exploring the potential and limitations of the use of UAVs in monitoring sugarcane. Through methodological developments to use the UAV data, was extracted qualitative and quantitative data and compared them with field and satellite data to test the study¿s hypothesis. The first part of this thesis describes an object-based image analysis (OBIA) procedure for UAV images, designed to map and extract information about skips in sugarcane planting rows. The approach achieved good results with a relationship of estimated versus observed skip length of 97%. The second part describes the generation of crop surface models (CSMs) derived from high-resolution images from the UAV to estimate the height of sugarcane fields. Also, was investigated the influence of different flight lines on the height estimation and the accuracies by comparing the generated maps with ground references. This method was ideal for estimating the average height of an entire field at once, instead of using point-wise ground measurements. In the third part, the UAV data (RGB) and the orbital platform data (multispectral, WorldView-2) were analyzed, to assess the capability of each system to represent the intra-field variability of sugarcane yield estimates. The results showed that the UAV data produced mean errors similarly, but with lower explanatory power compared to the WorldView-2 data. Moreover, the incorporation of both datasets (WorldView-2 + UAV) improved the accuracy. In summary, was concluded that a UAV system can provide useful decision-support data for improving sugarcane production. These platforms have the capability of providing very-high resolution images with near real-time acquisitionDoutoradoGestão de Sistemas na Agricultura e Desenvolvimento RuralDoutor em Engenharia Agrícola12/50048-7CAPESFAPES

Signals in the Soil: Subsurface Sensing

In this chapter, novel subsurface soil sensing approaches are presented for monitoring and real-time decision support system applications. The methods, materials, and operational feasibility aspects of soil sensors are explored. The soil sensing techniques covered in this chapter include aerial sensing, in-situ, proximal sensing, and remote sensing. The underlying mechanism used for sensing is also examined as well. The sensor selection and calibration techniques are described in detail. The chapter concludes with discussion of soil sensing challenges

Unmanned Aerial Vehicles for High-Throughput Phenotyping and Agronomic Research

Advances in automation and data science have led agriculturists to seek real-time, high-quality, high-volume crop data to accelerate crop improvement through breeding and to optimize agronomic practices. Breeders have recently gained massive data-collection capability in genome sequencing of plants. Faster phenotypic trait data collection and analysis relative to genetic data leads to faster and better selections in crop improvement. Furthermore, faster and higher-resolution crop data collection leads to greater capability for scientists and growers to improve precision-agriculture practices on increasingly larger farms; e.g., site-specific application of water and nutrients. Unmanned aerial vehicles (UAVs) have recently gained traction as agricultural data collection systems. Using UAVs for agricultural remote sensing is an innovative technology that differs from traditional remote sensing in more ways than strictly higher-resolution images; it provides many new and unique possibilities, as well as new and unique challenges. Herein we report on processes and lessons learned from year 1-the summer 2015 and winter 2016 growing seasons-of a large multidisciplinary project evaluating UAV images across a range of breeding and agronomic research trials on a large research farm. Included are team and project planning, UAV and sensor selection and integration, and data collection and analysis workflow. The study involved many crops and both breeding plots and agronomic fields. The project's goal was to develop methods for UAVs to collect high-quality, high-volume crop data with fast turnaround time to field scientists. The project included five teams: Administration, Flight Operations, Sensors, Data Management, and Field Research. Four case studies involving multiple crops in breeding and agronomic applications add practical descriptive detail. Lessons learned include critical information on sensors, air vehicles, and configuration parameters for both. As the first and most comprehensive project of its kind to date, these lessons are particularly salient to researchers embarking on agricultural research with UAVs

Evaluation of the UAV-Based Multispectral Imagery and Its Application for Crop Intra-Field Nitrogen Monitoring and Yield Prediction in Ontario

Unmanned Aerial Vehicle (UAV) has the capability of acquiring high spatial and temporal resolution images. This new technology fills the data gap between satellite and ground survey in agriculture. In addition, UAV-based crop monitoring and methods are new challenge of remote sensing application in agriculture. First, in my thesis the potential of UAV-based imagery was investigated to monitor spatial and temporal variation of crop status in comparison with RapidEye. The correlation between red-edge indices and LAI and biomass are higher for UAV-based imagery than that of RapidEye. Secondly, the nitrogen weight and yield in wheat was predicted using the UAV-based imagery. The intra-field nitrogen prediction model performs well at wheat early growth stage. Additionally, the best data collection time for yield prediction is at the end of booting stage. The results demonstrate the UAV-based data could be an alternative effective and affordable approach for farmers on intra-field management

Multispectral Remote Sensing for Yield Estimation Using High-Resolution Imagery From an Unmanned Aerial Vehicle

Satellites and autonomous unmanned aerial vehicles (UAVs) are two major platforms for acquiring remotely-sensed information of the earth’s surface. Due to the limitations of satellite-based imagery, such as coarse spatial resolution and fixed schedules, applications of UAVs as low-cost remote sensing systems are rapidly expanding in many research areas, particularly precision agriculture. UAVs can provide imagery with high spatial resolution (finer than 1 meter) and acquire information in visible, near infrared, and even thermal bands. In agriculture, vegetation characteristics such as health, water stress, and the amount of biomass, can be estimated using UAV imagery. In this study, three sets of high-resolution aerial imagery have been used for yield estimation based on vegetation indices. These images were captured by the Utah State University AggieAir™ UAV system flown in June 2017, August 2017, and October 2017 over a field experiment pasture site located in northern Utah. The pasture study area is primarily tall fescue. The field experiment includes 20 50 x 20-m plots, with 4 replications of 5 irrigation levels. Approximately 60 yield samples were harvested after each flight. Sample locations were recorded with high-accuracy real-time kinematic (RTK) GPS. In addition, the leaf area index (LAI) for each sample plot was measured using an optical sensor (LAI2200C) before harvesting. The relationship of yield for each sample versus vegetation indices (VIs) was explored. The VIs include the normalized difference vegetation index (NDVI), calculated using AggieAir imagery, and LAI measured using a ground-based sensor. The results of this study reveal the correlation between vegetation indices and the amount of biomass