Path Plan Performance Evaluation of the Challenge 1: A Small Unmanned Surface Vehicle for Radiation Detection and Mapping

This thesis will compare the performance of the Challenge 1 unmanned surface vehicle when autonomously conducting a radiological survey of a bounded, obstacle free, convex polygon via a traditional raster scan versus a novel spiral-like path plan. Currently, unmanned ground vehicles (UGV), unmanned aerial vehicles (UAV), and unmanned surface vehicles (USV) use a simple raster scan to insure complete coverage of a predefined, obstacle free area. Raster scans require a 180 degree change in heading which is easy for tracked UGVs and vertical take-o_ UAVs to accomplish, but more difficult for marine vehicles and fixed winged UAVs. A spiral-like path plan will not completely eliminate turns close to 180 degrees, but presents the possibility of removing the number of sharp turns at the expense of adding more slight turns. The author of this thesis originally hypothesized that this spiral-like path plan would result in shorter autonomous surveys by the Challenge 1 USV, as well as a higher percentage of coverage. Shorter surveys will allow operators such as the mission specialist overseeing a disaster in which radiological material may be present or treaty verification inspectors searching a facility to conduct more surveys in a limited time, which therefore increases the total area searched over this time period as well as provides data to the mission specialist faster. A higher percentage of coverage attained by the spiral-like path plan would guarantee a more complete representation of the area surveyed. To test this hypothesis the author used the 1.15 acre pond at John Crompton Park in College Station, Texas, to generate twenty-five unique convex polygons via teleoperation of the Challenge 1, ranging in size from 450 square meters to 1027 square meters, to which a raster path plan and spiral-like path plan were each used by the Challenge 1 to survey the area, resulting in fifty total runs. Following the data collection, the associated log from each run was used to calculate total survey time, total survey distance, root mean square of cross-track error, Hausdorff Distance (max RMS error), percent coverage, and percent of survey locations inside the bounded convex polygon. The average survey time for a spiral like path plan versus a raster scan was 13.68 seconds shorter (p < :59). The average total distance for a raster path versus a spiral like path was 15.53 meters less (p < :061). The average RMS of cross-track error for a spiral like path plan versus a spiral path plan was 0.31 meters less (p < :123). The average Hausdorff Distance for a spiral like path plan versus a raster scan was 1.53 meters less (p < 0:0005). The average of percent coverage for a raster scan versus a spiral like path was 4:22% higher (p < 0:027). The average of percentage of locations in the bounding area for a raster path versus a spiral like path was 16:88% higher (p < 0:00023). This shows that for α = :05, there is no statistical difference between either of the two path plans for survey time, survey distance, or RMS of cross-track error. However, there is a statistical difference between the two path plans for Hausdorff Distance, percent coverage and percentage of locations inside the bounding area. Due to the spiral path plan's inability to maintain locations inside the bounding area, a raster scan is the best path plan to use when surveying a bounded convex polygon with the Challenge 1 since it results in the highest percentage of coverage with no statistical difference in survey time, survey distance, or RMS of cross-track error. This result is only guaranteed for the Challenge 1 and its associated controller, with potentially different outcomes if tested on other surfaces vehicles, especially those with underwater propellers, rudders, or jet pump (no propeller or rudder) propulsion systems

Unmanned Aerial Vehicle (UAV)-Assisted Water Sampling

Water quality assessment programs require the collection of water samples for physical, chemical, and bacteriological analysis. Lack of personnel, accessibility of water bodies, and time constraints for water sampling, especially after natural disasters and emergencies, are some of the challenges of water sampling. To overcome these challenges, a water collection mechanism was developed and mounted on a multirotor unmanned aerial vehicle (UAV) for autonomous water sampling from water bodies. The payload capacity and endurance of the UAV (hexacopter) were verified using an indoor test station. The hexacopter was equipped with floating foam, and the electronic components were coated against water damage in case of landing on water due to emergencies or water sampling. The system was able to collect water samples 48 times out of 73 autonomous flight missions from a pond. The unsuccessful missions were mainly due to the malfunctions of the servo motor used in water sampler’s triggering mechanism. The servo motor for the mechanism was replaced to prevent the future malfunctions. UAV-assisted autonomous water sampling is a promising method for collection of water from water bodies. The system would be useful for collection of water samples from large lakes or difficult to access water sources. The details of the developed water sampling mechanism and the multirotor UAV, and experiment results are reported in this thesis

Space Systems: Emerging Technologies and Operations

SPACE SYSTEMS: EMERGING TECHNOLOGIES AND OPERATIONS is our seventh textbook in a series covering the world of UASs / CUAS/ UUVs. Other textbooks in our series are Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD); Disruptive Technologies with applications in Airline, Marine, Defense Industries; Unmanned Vehicle Systems & Operations On Air, Sea, Land; Counter Unmanned Aircraft Systems Technologies and Operations; Unmanned Aircraft Systems in the Cyber Domain: Protecting USA’s Advanced Air Assets, 2nd edition; and Unmanned Aircraft Systems (UAS) in the Cyber Domain Protecting USA\u27s Advanced Air Assets, 1st edition. Our previous six titles have received considerable global recognition in the field. (Nichols & Carter, 2022) (Nichols et al., 2021) (Nichols R. K. et al., 2020) (Nichols R. et al., 2020) (Nichols R. et al., 2019) (Nichols R. K., 2018) Our seventh title takes on a new purview of Space. Let\u27s think of Space as divided into four regions. These are Planets, solar systems, the great dark void (which fall into the purview of astronomers and astrophysics), and the Dreamer Region. The earth, from a measurement standpoint, is the baseline of Space. It is the purview of geographers, engineers, scientists, politicians, and romantics. Flying high above the earth are Satellites. Military and commercial organizations govern their purview. The lowest altitude at which air resistance is low enough to permit a single complete, unpowered orbit is approximately 80 miles (125 km) above the earth\u27s surface. Normal Low Earth Orbit (LEO) satellite launches range between 99 miles (160 km) to 155 miles (250 km). Satellites in higher orbits experience less drag and can remain in Space longer in service. Geosynchronous orbit is around 22,000 miles (35,000 km). However, orbits can be even higher. UASs (Drones) have a maximum altitude of about 33,000 ft (10 km) because rotating rotors become physically limiting. (Nichols R. et al., 2019) Recreational drones fly at or below 400 ft in controlled airspace (Class B, C, D, E) and are permitted with prior authorization by using a LAANC or DroneZone. Recreational drones are permitted to fly at or below 400 ft in Class G (uncontrolled) airspace. (FAA, 2022) However, between 400 ft and 33,000 ft is in the purview of DREAMERS. In the DREAMERS region, Space has its most interesting technological emergence. We see emerging technologies and operations that may have profound effects on humanity. This is the mission our book addresses. We look at the Dreamer Region from three perspectives:1) a Military view where intelligence, jamming, spoofing, advanced materials, and hypersonics are in play; 2) the Operational Dreamer Region; whichincludes Space-based platform vulnerabilities, trash, disaster recovery management, A.I., manufacturing, and extended reality; and 3) the Humanitarian Use of Space technologies; which includes precision agriculture wildlife tracking, fire risk zone identification, and improving the global food supply and cattle management. Here’s our book’s breakdown: SECTION 1 C4ISR and Emerging Space Technologies. C4ISR stands for Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance. Four chapters address the military: Current State of Space Operations; Satellite Killers and Hypersonic Drones; Space Electronic Warfare, Jamming, Spoofing, and ECD; and the challenges of Manufacturing in Space. SECTION 2: Space Challenges and Operations covers in five chapters a wide purview of challenges that result from operations in Space, such as Exploration of Key Infrastructure Vulnerabilities from Space-Based Platforms; Trash Collection and Tracking in Space; Leveraging Space for Disaster Risk Reduction and Management; Bio-threats to Agriculture and Solutions From Space; and rounding out the lineup is a chapter on Modelling, Simulation, and Extended Reality. SECTION 3: Humanitarian Use of Space Technologies is our DREAMERS section. It introduces effective use of Drones and Precision Agriculture; and Civilian Use of Space for Environmental, Wildlife Tracking, and Fire Risk Zone Identification. SECTION 3 is our Hope for Humanity and Positive Global Change. Just think if the technologies we discuss, when put into responsible hands, could increase food production by 1-2%. How many more millions of families could have food on their tables? State-of-the-Art research by a team of fifteen SMEs is incorporated into our book. We trust you will enjoy reading it as much as we have in its writing. There is hope for the future.https://newprairiepress.org/ebooks/1047/thumbnail.jp

Breeding Ecology of Mottled Ducks in Southwestern Louisiana

Mottled ducks are a resident species found in the southern United States that rely on coastal marsh and associated habitat to fulfill the needs of the entirety of their annual cycle. Population monitoring has revealed declines in western Gulf Coast (WGC) mottled ducks since 2008. Mottled duck populations are influenced by survival and recruitment, and changes in these factors may contribute to population declines. The overarching goal of this project was to identify the mechanisms potentially limiting WGC mottled ducks. I captured adult female mottled ducks during molt on Rockefeller Wildlife Refuge and adjacent lands in southwestern Louisiana from 2017–2019. I marked 148 individuals with a backpack solar-powered GPS-GSM transmitter and monitored them throughout the year for mortality and nest attempts. I used a Known Fate model in Program MARK to determine annual and seasonal survival and how survival varied temporally and spatially. Mottled duck survival was best explained by maximum partitioning of the year by the hunted periods and biological seasons and the proportion of GPS locations in agricultural land. Annual survival in this study was 0.60–0.64, one of the highest estimates for WGC mottled ducks. I identified 29 nest attempts during the breeding seasons 2018–2020. I used the nest survival model accessed through RMark to obtain daily survival rates of nests and evaluate the effect of local and landscape-level characteristics on survival. Nest survival varied positively with vegetation density. Lastly, I matched used nest sites with random locations within the home range of the female to examine nest site selection. Nest site selection varied by habitat type and vegetation density. Old fields were most likely to be selected, while emergent marsh was least likely to be selected. Probability of use also varied positively with vegetation density. During this study, survival estimates were similar to that of waterfowl species not experiencing declines and nest success and renesting propensity were relatively high. Nesting propensity was very low and future research should further investigate cues mottled ducks use to initiate nesting

2016, UMaine News Press Releases

This is a catalog of press releases put out by the University of Maine Division of Marketing and Communications between January 4, 2016 and December 30, 2016

Digest, Senate and House bills and resolutions

Published annually, the final Legislative Digest is a compilation of legislation of the Senate and House of Representatives including bill number, sponsors, and bill history actions. The Digest contains specific reports as to subject matter, sponsors and ratified legislation. The Digest is published at the completion of the annual legislative session after all enacted legislation has been assigned act numbers

Digest, Senate and House bills and resolutions

Published annually, the final Legislative Digest is a compilation of legislation of the Senate and House of Representatives including bill number, sponsors, and bill history actions. The Digest contains specific reports as to subject matter, sponsors and ratified legislation. The Digest is published at the completion of the annual legislative session after all enacted legislation has been assigned act numbers

Digest, Senate and House bills and resolutions 

Published annually, the final Legislative Digest is a compilation of legislation of the Senate and House of Representatives including bill number, sponsors, and bill history actions. The Digest contains specific reports as to subject matter, sponsors and ratified legislation. The Digest is published at the completion of the annual legislative session after all enacted legislation has been assigned act numbers