ABSTRACT. Food security has always been of great importance to governments around the world. The importance of food security has even grown larger due to recent events, where the yield of particular crops has gone smaller and wars have disrupted the exports of other crops. Therefore, the development of agriculture is critical to food security. Such a development can benefit from numerous technologies that help in increasing the crop yield yearlong. Unmanned Aerial Vehicles – also known as drones – have made their way into the agricultural sector in recent years by using them to carry out operations such as monitoring the growth and health of plants, spraying crops with pesticides, and livestock management. They have proven to be very effective in obtaining farm data efficiently and accurately; allowing the farmer to make more informed decisions on the use of water, fertilizers, and other resources. Unfortunately, Omani farmers have yet to take full advantage of technology, as they still rely on traditional farming methods. This paper proposes the utilization of drones, remote sensing, and machine vision technologies to provide the farmer with an intelligent agricultural crop monitoring system. The farmer is provided with a friendly online dashboard to provide him/her with real-time data regarding the health of the farm. The results obtained from the field tests, conducted at Sultan Qaboos University farms, can help the farmers in improving the yield of the farms, which will reduce losses and increase revenues.

ABSTRACT. The current paper aims to analyze the design and the efficiency of a small scale solar powered UAV. The selection of solar cells is performed in view of the current solar cell technologies. The aerodynamic analysis and the initial design of a small scaled UAV wing that use flexible solar cells are performed. Solar-array area on the upper surface of the wing and the sunlight direction seen by these arrays during the flight at different time of the day are the main parameters for the energy storage system in order to obtain effective solar energy for the flight. The solar irradiance at Muscat, Oman is taken into consideration. The power management during the daytime and battery recharge effectiveness during the night flight is investigated. Small-scale UAV is considered to cruise at sea-level with 25 m/s cruise velocity corresponding to a Reynolds number of 6.16×10⁵. Five different low Reynolds number airfoils are considered, and NACA6409 is selected as the airfoil of the designed wing. The power obtained from solar cell arrays mounted on the upper side wing are calculated on 21 June at the sea level condition considering latitude and longitude of Muscat, Oman

ABSTRACT. The Gurney flap is known as a simple and a small device that may assist in rising the life coefficient of the wings and aerofoil, that way shortening the distance of the aircraft to take off. The location of these simple flaps is perpendicular to the suction side of an aerofoil, particularly near the trailing edge. The location of these simple flaps is perpendicular to the suction side of an aerofoil, particularly near the trailing edge. With the addition of the Gurney flap, the trail is stabilized which assures laminar flow though the suction part and hence turns the shock. This investigation studied the influencing aerodynamics of a Gurney flap on a Multi-Element aerofoil for the subsonic situation. The numerical analysis of this investigation was implemented by using the Computational Fluid Dynamics (Star ccm+ software) program to indicate the flow domain over the aerofoil. Indeed that the Flap height range was from 1.5% to 3% of the aerofoil chord length. Also, the investigation of the impact of the Gurney flap was considered at a 0° to 30° angle of attack. The results of adding a Gurney flap and without a Gurney flap have been compared after validating the result of Multi-Element aerofoil without a Gurney flap with experimental data in the AGARD Report [1]. The investigation indicates that the optimal dimension of the device is consistently below the thickness of the boundary layer at the edge of the trailing and it tends to raise the lift to drag ratio remarkably. By validating, simulation results were very close which indicates a great mesh that has been implemented by CFD. Also, the height of 1.5%c to 2%c gives the best performance of using the Gurney flap. The investigation ended up with a recommendation that the Gurney flap may assist to reduce the drag reduction coefficient prior to the stall.

ABSTRACT. Visual investigation methods are conventionally applied during structural integrity inspection and defect detection. Inaccessible zones and field inspection restrictions are applicable to tall buildings, large bridges, dams, power plants as well as large commercial airliners. Through the fast technological progress of unmanned aerial vehicle (UAV) and recent advances in digital image processing techniques, conventional visual inspection could soon become obsolete. A defect detection approach utilising the advanced UAV and digital image processing techniques is proposed in this paper. This study is part of a bigger research investigating into the ability of an advanced UAV to autonomously traverse over an aircraft and accurately detect locations of defects on the aircraft skin to assist in further investigation of subsurface defects utilizing thermal and ultrasound techniques. The main aim of the research study is to minimize the inspection time of a commercial aircraft to the order of an hour.

ABSTRACT. UAVs are becoming most useful flying vehicles with multiple applications. The design and specifications of the proposed SUAV are inspired by the PHASA-35 and Zephyr-7 projects. The two projects reached an altitude of more than 20,000 m and weighed 150 and 53 kg respectively. It was shown that such an aircraft would be economical and capable of replacing conventional machines with reduced fuel, emissions, and maintenance burden. The purpose of this research was to design an analyze the solar powered high altitude long endurance (HALE) unmanned aerial vehicle (UAV). The designed aircraft can fly with multiple civilian and military applications including communication, weather monitoring, surveillance of land and coastal boarder and fire detection. Available commercial software ANSYS and Solid works are used for modelling and aerodynamics analysis of SUAV. In the design, energy is extracted from solar arrays, in the morning for normal operation and some of it is stored for night operations. The acquired results are compared with published studies on similar designs.

ABSTRACT. Illegal operations of drones pose significant threats to public security and personal privacy. This research aims to develop a cost-effective drone jammer to eliminate the illegal operations of drones. Barrage jamming and sweep jamming techniques were implemented using Software-Defined radios (SDR) platform called HackRF One. The results showed that as the amplitude of the analogue barrage jamming signal increases, the strength of the signal increases, and jamming efficiency improves. Also, the results demonstrated that jamming efficiency is better at a sampling rate of 20 MHz. The performance of the digital barrage jamming using Quadrature Phase Shift Keying (QPSK) modulation and Differential Quadrature Phase Shift Keying (DQPSK) modulation was better than Binary phase Shift keying (BPSK) modulation, and 8 PhaseShift Keying (8PSK). The results of the sweep jamming technique were unsatisfactory. The recommended jammer that achieved the optimum results is based on the analogue barrage jamming technique, and the signal is fast noise with an amplitude of 15, a sampling rate of 20MHz, and a bandwidth of 20 MHz. The recommended jammer successfully jammed the drone that was placed 1 meter from the jammer and 16 meters from the remote control.

ABSTRACT. Flight operations, being conducted both in commercial and military sectors, demand reliable and real-time radio communication between the aircraft and air traffic controlling (ATC) agencies. Undesirable background and channel noises during radio transmission (RT) increase pilots’ listening fatigue and pose a potential of serious air safety hazard. Established speech enhancement methods such as spectral subtraction (SS) are crucial in enhancing the quality of communication by separating speech from background noise in the transmitted audio signals along with the basic requirement of reliability and low latency. This paper proposes a speech enhancement technique for real-time audio communication over radio between pilots and ATC based on SS and a Deep Neural Network (DNN). Spectral Subtraction estimates noise in the audio spectrum and subtracts it from the noisy speech signal. The DNN is trained using a dataset of clean and noisy speech signals recorded in real-world aviation scenarios. Signal synthesis module is utilized to calculate magnitude and phase of the speech; where the magnitude is modified by the neural network, and then it is reconstructed with the original phase. The proposed methods are evaluated using objective measures such as signal-to-noise ratio (SNR), perceptual evaluation of speech quality (PESQ), as well as subjective evaluations by human listeners in the form of mean opinion score (MOS).

ABSTRACT. The L Band Digital Aeronautical Communication System (LDACS) is a new generation of air-ground communication systems designed to meet the increasing demand for air traffic data transmission. It is based on cellular concept. The system has been under trial in Europe. This paper presents a detailed architecture and simulated performance validation of LDACS in Northern Airspace of Pakistan. The focus is on the system's ability to provide high-speed data transmission, improved coverage, and increased spectrum efficiency while ensuring compatibility with existing communication systems. The LDACS system is intended to provide a reliable, secure, and cost-effective solution for air-ground communication in the L band frequency range. The paper primarily verifies performance verification of Communication and Navigation features. The verification of communication comprises coverage, reliability in terms of BER, Cell sizes for frequency reuse. The modulation scheme is Orthogonal Frequency Division Multiplexing (OFDM) where sub-carriers are to be adjusted in available pockets “L” band. The Navigation feature is tested in terms of flight path accuracy and Required Navigation Performance (RNP) category is determined. Simulations are carried out using GNU radio, and MATLAB.

ABSTRACT. Over the past few years, the use of Unmanned Aerial Vehicles (UAVs) has increased because of their greater adaptability and reduced mission cost. Recent developments in drone technology and the increased complexity of mission environment, have led to the use of multiple UAVs. Considering the dynamics of an uncertain environment, a Decentralized Cooperative Path Planning algorithm has been implemented in this paper which allows each agent to coordinate effectively in an area where communication with Ground Control Station is constrained. An Ant Colony Optimization based algorithm has been implemented for multiple UAVs to cooperatively search a given area. The developed algorithm incorporates maneuverability, collision avoidance, and threat avoidance constraints. An overall efficient path for each UAV is planned by using State Transformation Rule and Pheromone Update Mechanism at each time interval. An improved heuristic has been proposed as an improvement to the developed algorithm to reduce the maneuvering cost of UAVs. Generated paths for each UAV have been validated by using Hardware in the Loop testing on multiple UAVs by using Dronekit-Python and Mission Planner. Results show that the use of multiple UAVs is effective for path planning in surveillance missions as it increases the coverage efficiency and reduces the overall mission time.

ABSTRACT. All aircraft engines work by pushing something backwards so that the aircraft moves forward. Usually this is air, whether cold air driven by propellers or hot air fired out by jet engines. Ionic propulsion instead uses charged particles or ions that are generated using high voltages inbetween two electrodes. The ions interact with the surrounding air, creating an ionic wind that is sent backwards, propelling the aircraft forward.

As with propeller-driven solar powered aircraft, ion drive craft are powered by electricity and do not need to carry fuel, other than batteries filled with charged particles. As well as being carbon neutral, they are less likely to go wrong and cheaper to maintain than conventional engines because they have no propellers, turbines or fuel pumps to break down. The main problem is that, in Earth’s gravity, the thrust produced by the drive isn’t enough to overcome the weight of the batteries needed to power it. However, with advances in battery setup and the way the electrical power is converted, it has been possible to reduce the battery weight enough to make this technology fly under its own power.

The use of Computational Fluid Dynamics (CFD) to model the ionic wind can further improve efficiency. Its use is demonstrated with validation by comparing with a previous experimental study. Numerical calculations can provide an estimated value of generated thrust using voltage and a given distance between the emitter and collector. Specified conditions are used to generate a simulation of ionic wind for a lightweight aircraft.

Making further advances in materials and power electronics, and optimising the airframe, could enable the aircraft to fly faster and for longer. These aircraft engines have no moving parts, produces no harmful exhaust and make no noise. So it’s likely the technology will find its first application in silent drones. But with further advances in materials and power conversion, silent crewed aircraft and eventually commercial flights could also be on the distant horizon.

ABSTRACT. Helmet-Mounted Displays (HMDs) need variable transmission technology-equipped goggles, spectacles, and visors. The majority of HMDs currently do not allow the pilot to alter the transmission level of a flight visor as the light level varies from high to low. In situations where HMDs are not required, sunglasses are commonly worn, but their use becomes impractical when HMDs are required. Concern exists in both civilian and military organizations for those who experience temporary blindness when transitioning from high to low brightness levels. Using electrochromic technology, a variable transmittance visor that can be adjusted manually or automatically might be the solution for the pilot. Adjusting the visor's absorption level with an electric field enables a range of brightness adjustments. Applying a voltage to the visor alters the optical density continuously from transparent to opaque or vice versa. However, the BH1750 digital light sensor will assist in determining the required voltage for the visor's transition from clear to dark. Multiple layers will compose the visor, including two external layers of transparent conductive films, a counter electrode layer, an electrolyte layer, and an electrochromic electrode layer. In addition, the principal components of the visor are Ag nanorods coated in tungsten oxide (WO3), as this material will cover the visor and provide an immediate change from transparent to dark in 5.7 seconds. Numerous factors must be considered before implementing this technology into the visor, such as the light sensor's operating conditions and the required amount of energy. Additionally, the design of the visor has to include a current path to ensure that the visor shifts properly.

ABSTRACT. Along with the dominant and security critical applications of Artificial Intelligence (AI), existence of its perils cannot be undermined. However, such threats become a blessing in disguise in scenarios where vulnerable assets are required to be hidden from autonomous systems including drones and UAVs. The hazards of Adversarial attacks on deep neural network (DNN) models are well known by research community. The intent of these attacks is to cause the DNN model to make inaccurate predictions or judgements. The aforementioned attacks signify a fundamental change in security-sensitive situations within practical contexts, wherein it becomes imperative to conceal vulnerable assets from self-governing detection mechanisms present on drones and unmanned aerial vehicles (UAVs). This paper presents a unique research in utilizing adversarial attacks to deceive autonomous detection systems onboard aerial reconnaissance, detection and surveillance systems. We provide a framework to deceive YOLOv3 object detection model through patch based attack by camouflaging a parked aircraft from overhead imaging. Our study successfully demonstrated patches when overlaid on minimal area of aircraft, was able to blind detection system with much greater accuracy. This work also aims to highlight the use of such methods in security related applications.

ABSTRACT. The project's goal was to create a system for solar-powered unmanned aerial vehicles (SPUAV). The concept of SPUAVs simply stands for Unmanned Aerial Vehicle (UAV) covered with solar panels. During the daytime flight, the panels get solar energy from the sun and then convert it into electrical energy that is used to power the engine. The excess electrical energy is stored in the battery for the night flight. The SPUAV PHASA-35 had an influence on this project. By reducing the dimensions of the PHASA-35 by 10%, the SPUAV's wingspan reached to 3.5 meters. The system endurance was determined to be able to operate for 12 hours continuously. Software from ANSYS and Multisim was used to analyze the SPUAV's electrical and aerodynamic performance. By providing the SPUAV with a camera, this project can be used to monitor illegal immigration attempts across the Omani borders and track missing persons at sea or in the mountains, because these tasks require continuous flight operations.

ABSTRACT. Research and development in the field of Space Debris Remediation (SDR) technologies has gathered rapid momentum in the last two decades. Amongst a variety of technologies which are being investigated, the robotic manipulator coupled with an end-effector system offers a feasible option for active SDR missions. In the current work, the utilization aspect of a robotic system is addressed by conducting a focused survey of pertinent utility characteristics associated with the practical employment of the system. One such configuration that merits special attention is the possible employment of a 4-degrees of freedom robotic system integrated with an end-effector mechanism which uses a Light Detection and Ranging (LIDAR) system for the identification of debris. Additional investigation into universal mathematical models related to key utilization aspects can also be conducted for use in the future phases of this continual project. This paper is formulated to act as a bridge between space robot design and its application domains.