How does drone technology work?

There is a broad range of potential civil and commercial applications for which drones are attractive platforms.

Drones are getting popular in the agriculture and allied sector for performing different tasks such as crop scouting, weed mapping, spraying, yield estimation, crop, and water source identification, estimation of vegetation indices, assess crop insurance claims, soil analysis, health and vigor assessment of crops, and irrigation and nutrient management.

• Moreover, they also find their applications in forestry, fisheries, livestock management, and wildlife conservation.

Drones are flying robots, which include unmanned aerial vehicles (UAVs) capable of flying thousands of kilometers and mini drones that can fly in confined spaces.

• Prominent alternative terms commonly used in various parts of the world and different contexts include Remotely Piloted Aircraft (RPA), Unmanned Aerial Vehicle (UAV) and Unmanned Aircraft System (UAS).

Generally, drones are classified into three categories based on their aero-dynamic characteristics viz fixed-wing, rotary-wing and hybrid.

• Depending on the number of rotors, a rotary-wing drone can be categorized as tri-copters, quadcopters, hex copters and octocopters that are lifted and propelled by three, four, six, and eight rotors, respectively.

• In a four-rotor system, two opposite rotors rotate clockwise (CW) and the other two rotate counter-clockwise (CCW). The quad-copter movement around the axis includes pitch (backward and forward), roll (left and right), and yaw (clockwise and counter-clockwise).

• In India, drones are classified into five categories based on their weight i.e., nano (<0.25 kg), micro (0.25-2.0 kg), small (2.0-25 kg), medium (25-150 kg), and large (>150 KG).

Why drones?

Nowadays, higher doses of fertilizers, pesticides and other agrochemicals have been used under the conventional agriculture systems (CAS).

Climate change and environmental pollution are the major global issues of the current era and severely impacting agricultural productivity. More than 815 million people are chronically hungry and 64 percent of the chronically hungry in Asia (FAO, 2018).

Drone technology has gotten most of the recognition in the industry because of its diversity and is considered the future of the agrarian community. With the world’s population projected to reach 9 billion people by 2050, experts expect agricultural consumption to increase by nearly 70 percent over the same time period. In such a situation, drone technology could be helpful and may satisfy the increasing future needs.

HOW DOES DRONE TECHNOLOGY WORK?

Typically, drones include a navigation system, GPS, multiple sensors, high-quality cameras, programmable controllers, and tools for autonomous drones. The DJI is one such familiar drone utilized by the industry. Most farmers currently use satellite imagery as an introductory guide for farm management.

SOFTWARE:

Drones have unleashed new ways of capturing data through advanced cameras and sensors that can be converted into actionable insights.

• ArcGIS Drone2Map: ArcGIS Drone2Map streamlines the surveying and mapping process, and provides orthomosaics, 3D meshes and so on. It is a premium app for ArcGIS Online, which helps to transform the images collected by the drone into high-quality 2D and 3D models.

• DJI Terra: Agriculture version includes features such as easy mapping of orchards, precise management of crops, and generating vegetation indices maps (NDVI and NDRE maps) by using multi-spectral images.

• Pix4D mapper: software is designed for professional drone mapping applications and supports the processing of RGB, thermal and multi-spectral images. Maps are created rapidly with no requirement for internet connectivity. This helps in easy scouting of the farm and generating various useful outputs such as vegetation index maps, field boundaries, digital surface models, zonation maps, etc

• DroneDeploy: can process massive amounts of data gathered from drones to produce insight-rich 2D and 3D models. DroneDeploy is capable of solving many agriculture problems such as identifying the crop damage, and pest and diseases infestation, and drawing inferences based on crop growth and responding to weather changes.

• Agisoft Metashape: Agi soft meta shape is a stand-alone photogrammetric software solution, capable of performing geo-referenced orthomosaics and digital surface models (DSM) from images with high accuracy ). Using Meta shape, detailed 3D models are created from images and models are exported to all external post-processing packages. The tool allows the processing of images from various sources such as RGB and multi-spectral cameras.

Drones used in agriculture collect data from geographical positioning system (GPS) and sensor-equipped farm equipment and transmit data to a ground control station (GCS) via satellite.

• Data are then transferred to the users over the internet for data analysis and regulation of farm implements.

• The GCS gathers information on the drones in the fleet, such as geographic data, and prepares and manages drone fleet missions. The fleet is a collection of many drones that get a mission from GCS and work together to complete it.

• It is critical to ensure connectivity between drones and GCS to implement drone-assisted wireless communications and instruction to the field implements.

• Drones can also be used as standalone input applicators for site-specific management.

Advancement in multi-spectral imaging techniques and electronic sensors has enabled farmers to extract detailed information on soil and crop health.

Drones are currently emerging as a component of precision agriculture along with contributing to sustainable agriculture. Various sensitive sensors or bands of electromagnetic waves are used in the drones based upon the purpose in agriculture.

Red, Green, and Blue (RGB) bands -These bands are used for counting the number of plants, for modeling elevation, and visual inspection of the crop field.

Near Infra-Red (NIR) band -This band is used for water management, erosion analysis, plant counting, soil moisture analysis, and assessment of crop health.

Red Edge band (RE)- It is used for plant counting, water management, and crop health assessment.

Thermal Infra-Red band -This band has applicability in irrigation scheduling, analyzing plant physiology, and yield forecasting.

NDVI Sensor: It helps us to know about the health status of the plant. Healthy plants have a strong near infrared (NIR) reflectivity, called the "Red Edge".

NDVI range = NIR- Red / NIR + Red

Ranges of NDVI: • Dead plants: <0 • Unhealthy plants: < 0.33 • Healthy plant: >0.33 to < 0.66 • Very healthy plants: >0.66.

Sentera with Field Agent: Process sensor data and gain NDVI and NDRE insights • Generate Ortho mosaic maps.

• Autonomously fly your drone within a selected area.

1. Drones are now commonly used for precise application of agricultural inputs along with growth monitoring, plant health management and yield estimation.

2. Drones offer an enormous possibility for wider adaptability in agriculture by data acquisition, processing and enhancing the performance of monitoring systems.

3. Moreover, drone is easy to operate, cost-effective and requires the least possible time to acquire field data as compared to conventional methods.

4. A drone equipped with a high-resolution camera can fly at low altitudes to acquire images with ultra-high spatial resolution.

5. A drone provides a non-destructive way to cover a larger field in a short time as compared to ground-based systems.

6. Multispectral sensors allow seizing data useful for seed planting patterns, thorough field soil analysis, irrigation, and nitrogen-level management., moisture content, nutrients content and fertility levels of the soil which can be further used for planning the pattern of sowing of different crops, irrigation scheduling as well as for managing fertilizers application considering spatial variability of the crop growth and field conditions. After getting precise 3D maps for soil, planting can be planned, and nutrient status can be analyzed for further operations.

Including remote sensing methods for estimating crop yield include

1. Based on empirical statistical models,

2. Based on water consumption balance models, and

3. Based on biomass estimation models.

Crop height and biomass are important components for assessing growth rate and health of crops.

• Plant height and biomass data are important components for assessing the effect of genetic variation in the crops, crop development and yield potential.

• The two components are essential for optimizing site-specific crop management and yield predictions.

The most important crop characteristic is biomass, which, when combined with information on nitrogen content, can be used to predict whether extra fertilizer or other activities are required.

Drones have the potential to collect crop data in a consistent manner, allowing farmers to plan crop management, input utilization, plan harvesting time, soil and yield monitoring and identify any management flaws in a controlled manner.

HARDWARE:

• Drone airframe: Drone airframe provides the support for mounting electronic components, sensors and rotors. The frame is designed to be light in weight and has strength to carry the load. Various materials such as plastic, aluminum, fiber and wood are used for creating rigid airframes.

• Communication system: The communication system is responsible for data flow between the ground control station (GCS) and the drones. The pilot can transmit task-specific commands via a radio transmitter present in the GCS. The GCS software captures telemetry data from the drones and is capable of visualizing it in the GCS user interface. The information collected from the sensors can be partially analyzed in real-time or sent to the ground station for analysis.

• Motor/speed controllers: Motors in drones are responsible for spinning the propellers and make a huge impact on flight time. The selection of motors mainly depends on the weight of the drone. The motor should be capable enough to generate thrust to overcome the weight of the drone and achieve a lift-off. The electronic speed controller (ESC) helps the flight controller to control each motor individually and stabilize the system.

• Sensors and camera: Sensors and cameras are two major components outfitted in drones. The motion control is performed based on the sensor data received from the sensor attached to it. As continuous monitoring of position, velocity and acceleration are required; gyro, accelerometer and magnetometer combinations are incorporated as a sensor set in the drones. GPS is also enabled for tracking the live location of the drone. The multi-spectral camera collects images at specific frequencies, whereas hyper-spectral cameras are mounted for capturing images at narrow spectral bands.

• Flight controller: The flight controller is a small computer system, which acts as the heart of the drone and is responsible for directing the flight of drone along its flight path. Generally, it allows multiple flight modes which can be selected with the help of a transmitter switch.

Using Drone for Land Use Mapping:

A drone can inspect a bigger area of agricultural land with much higher spatial and temporal details. Drones fitted with LIDAR sensors can be used to survey and monitor orchard fields.

• Surveying the nutritional condition of the soil at different soil types, nutrient ranges, and nutrient requirements within and between fields is another area where drones can be used. Drones can be used to reduce unlawful stubble burning in agricultural fields in India, where it is a big issue and a threat to the environment.

Soil and field analysis can be done using drones.

• They may be used to create precise 3-D maps that can be utilized to undertake soil analysis for soil properties, moisture content, and erosion. When it comes to seed planting patterns, this is crucial. Even after planting, these data are useful for irrigation and nitrogen management. The crop monitoring in large fields is one of the biggest challenges in farming.

• Drone can be used for collection of data for crop monitoring, yield prediction etc. followed by data interpretation about crop damage, yield and coverage and to facilitate effective crop management techniques to increase income and improve crop quality. The complete procedure is facilitated with GCS and GPS imagery.

Drones in HORTICULTURE:

A few important applications of drones in horticulture sector are-

• Crop-based leaf area indexing for determination of plant health (biotic and abiotic stresses), tree density etc.

• Imaging of horticultural crops in challenging situations like changing weather conditions, terrain, effect of sunlight, fog, etc.

• Plant yield monitoring, scouting and bird scaring.

• Ascertaining the land surface temperature, spatial variability in crop yields, water inventories of ground water, retrieving type of irrigation, etc.

Drone Startups and business in INDIAN Agriculture:

1. A Bengaluru-based drone start-up collaborated with the Indian unit of Swiss agri-business major Syngenta to utilize drones to analyze the cultivable regions for corn in India as a part of an effort to adopt precision agriculture.

2. Swarms of locusts have infested numerous parts of India particularly Rajasthan state in 2020. Drones have been used in Rajasthan state for efficient spraying of organo-phosphate insecticides in small and concentrated amount to control locust attack. They can spray insecticides across one hectare area in less than 15 min.

3. Agricultural drones developed by Kakkanad-based start-ups sprayed micronutrients over the paddy fields of Alathur in Kochi district of Kerala.

4. In Andhra Pradesh, Acharya NG Ranga Agriculture University (ANGRAU) is intending to deploy drones in the agriculture sector to spray pesticides. Recently, the university purchased five different drones under the APSARA (Centre for AP Sensors and Smart Applications Research in Agriculture) program are under testing.

5. Tractors and Farm Equipment Limited, Chennai, is experimenting with drone-based aerial spraying to check crop health and prevent crop disease from spreading.

6. Agricultural trials using drones and precision spraying on rice and hot pepper crops are being carried out by M/s Mahindra & Mahindra, Mumbai, in the states of Telangana and Andhra Pradesh, respectively.

7. Bayer Crop Science based in Mumbai is doing agricultural research on agricultural spraying using drones.

Check out previous article on Drone technology in Indiahttps://www.seedlearner.com/post/drone-technologies-of-india

BY KHAS.