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Full-Text Articles in Electrical and Computer Engineering

Prediction Models For Estimation Of Soil Moisture Content, Swathi Gorthi Dec 2011

Prediction Models For Estimation Of Soil Moisture Content, Swathi Gorthi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Center for Self-Organizing Intelligent Systems (CSOIS) has been successful in developing personal remote sensing systems. These systems can be further enhanced to monitor important resources of earth such as soil moisture content. Soil moisture is the major component of the soil in relation to plant growth. Soil water dissolves salts and makes up the soil solution, which is important as medium for supply of nutrients to growing plants.

Usually, measuring such physical quantities would include using derived formulas that mathematically describe the relationships between the parameters involved. With the advancements in computer modeling, other methods such as empirical modeling …


Distributed Electrical Power System In Cubesat Applications, Robert Burt Dec 2011

Distributed Electrical Power System In Cubesat Applications, Robert Burt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cubesat spacecraft was conceived over ten years ago. Since that time, close to 100 cubesat satellites have either been launched or are in the process of construction. Although started as an educational teaching tool, the cubesat is gaining popularity in the satellite industry and is making inroads as a standard architecture for many nano and pico satellite applications. The electrical power system for the cubesat class satellites almost exclusively conforms to a centralized architecture.

This thesis researches the potential of using a distributed architecture for the cubesat power system. There are several key advantages of a distributed architecture that …


Inkjet-Printed Highly Transparent Solar Cell Antennas, Jesus A. Arellano Dec 2011

Inkjet-Printed Highly Transparent Solar Cell Antennas, Jesus A. Arellano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Small satellites, especially Cube Satellites (CubeSats), have become important vehicles for space exploration. One of the challenges CubeSats face is limited surface area. This limitation poses a question for antenna design–where to mount the antenna? Transparent antenna is a solution to resolve the competition between solar cells and antennas for surface area. The transparent antennas can be directly integrated on top of solar cells without requiring additional space. It is for this reason that this thesis focuses on the integration of highly transparent meshed antenna with solar cells. Even though transparent antennas allow light to travel light through them, they …


Cognitive Formation Flight In Multi-Unmanned Aerial Vehicle-Based Personal Remote Sensing Systems, Long Di Aug 2011

Cognitive Formation Flight In Multi-Unmanned Aerial Vehicle-Based Personal Remote Sensing Systems, Long Di

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work introduces a design and implementation of using multiple unmanned aerial vehicles (UAVs) to achieve cooperative formation flight based on the personal remote sensing platforms developed by the author and the colleagues in the Center for Self-Organizing and Intelligent Systems (CSOIS). The main research objective is to simulate the multiple UAV system, design a multi-agent controller to achieve simulated formation flight with formation reconfiguration and real-time controller tuning functions, implement the control system on actual UAV platforms and demonstrate the control strategy and various formation scenarios in practical flight tests. Research combines analysis on flight control stabilities, develop- ment …


Autonomous Aerial Manipulation Using A Quadrotor, Vaibhav Ghadiok Aug 2011

Autonomous Aerial Manipulation Using A Quadrotor, Vaibhav Ghadiok

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents an implementation of autonomous indoor aerial gripping using a low-cost, custom-built quadrotor. Such research extends the typical functionality of micro air vehicles (MAV) from passive observation and sensing to dynamic interaction with the environment. To achieve this, three major challenges are overcome: precise positioning, sensing and manipulation of the object, and stabilization in the presence of disturbance due to interaction with the object. Navigation in both indoor and outdoor unstructured, Global Positioning System-denied (GPS-denied) environments is achieved using a visual Simultaneous Localization and Mapping (SLAM) algorithm that relies on an onboard monocular camera. A secondary camera, capable …


Document Flash Thermography, Cory A. Larsen Aug 2011

Document Flash Thermography, Cory A. Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents the application of ash thermography techniques to the analysis of documents. The motivation for this research is to develop the ability to non-destructively reveal covered writings in archaeological artifacts such as the Codex Selden or Egyptian car- tonnage. Current common signal processing techniques are evaluated for their effectiveness in enhancing subsurface writings found within a set of test documents. These processing techniques include: false colorization, contrast stretching, histogram equalization, median altering, Gaussian low-pass altering, layered signal reconstruction and thermal signal reconstruction (TSR), several contrast image definitions, differential absolute contrast (DAC), correlated contrast, derivative images, principal component thermography …


A Two-Dimensional Numerical Simulation Of Plasma Wake Structure Around A Cubesat, Rajendra Mitharwal Aug 2011

A Two-Dimensional Numerical Simulation Of Plasma Wake Structure Around A Cubesat, Rajendra Mitharwal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A numerical model was developed to understand the time evolution of a wake structure around a CubeSat moving in a plasma with transonic speed. A cubeSat operates in the F2 layer of ionosphere with an altitude of 300 − 600 Km. The average plasma density varies between 10−6cm−3 − 10−9cm−3 and the temperature of ions and electrons is found between 0.1−0.2 eV. The study of a wake structure can provide insights for its effects on the measurements obtained from space instruments. The CubeSat is modeled to have a metal surface, which is a realistic …


Perching Using A Quadrotor With Onboard Sensing, Jeremy C. Goldin May 2011

Perching Using A Quadrotor With Onboard Sensing, Jeremy C. Goldin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents an implementation of autonomous indoor perching using only onboard sensors on a low-cost, custom-built quadrotor. The perching aggressive maneuver is representative of a class of control problems for aerobatics that requires an agile and robust control system for maneuvering accurately at high speeds. Such research extends the typical functionality of micro air vehicles (MAV) from low speed and stationary observation to dynamic aerobatic transitions for broader operational capabilities including confined landings and evasive maneuvering. To achieve this, three major challenges are overcome: precise and real-time positioning, sensing of the perch and path to the perch, and control …


Enhancing Multispectral Imagery Of Ancient Documents, Trace A. Griffiths May 2011

Enhancing Multispectral Imagery Of Ancient Documents, Trace A. Griffiths

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multispectral imaging (MSI) provides a wealth of imagery data that, together with modern signal processing techniques, facilitates the enhancement of document images. In this thesis, four topic areas are reviewed and applied to ancient documents. They are image fusion, matched filters, bleed-through removal, and shadow removal. These four areas of focus provide useful tools for papyrologists studying the digital imagery of documents. The results presented form a strong case for the utility of MSI data over the use of a single image captured at any given wavelength of light.


Signal Processing On Digitized Ladar Waveforms For Enhanced Resolution On Surface Edges, Kevin D. Neilsen May 2011

Signal Processing On Digitized Ladar Waveforms For Enhanced Resolution On Surface Edges, Kevin D. Neilsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Automatic target recognition (ATR) relies on images from various sensors including 3-D imaging ladar. The accuracy of recognizing a target is highly dependent on the number of points on the target. The highest spatial frequencies of a target are located on edges. Therefore, a higher sampling density is desirable at these locations. A ladar receiver captures information on edges by detecting two surfaces when the beam lands partially on one surface and partially on another if the distance between the surfaces is greater than the temporal pulse width of the laser.

In recent years, the ability to digitize the intensity …


Model-Based Stripmap Synthetic Aperture Radar Processing, Roger D. West May 2011

Model-Based Stripmap Synthetic Aperture Radar Processing, Roger D. West

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Synthetic aperture radar (SAR) is a type of remote sensor that provides its own illumination and is capable of forming high resolution images of the reflectivity of a scene. The reflectivity of the scene that is measured is dependent on the choice of carrier frequency; different carrier frequencies will yield different images of the same scene.

There are different modes for SAR sensors; two common modes are spotlight mode and stripmap mode. Furthermore, SAR sensors can either be continuously transmitting a signal, or they can transmit a pulse at some pulse repetition frequency (PRF). The work in this dissertation is …