Mapping water content in drying Antarctic moss communities using UAS-borne SWIR imaging spectroscopy

Antarctic moss beds are sensitive to climatic conditions, and both their survival and community composition are particularly influenced by the availability of liquid water over summer. As Antarctic regions increasingly face climate pressures (e.g., changing hydrology and heat waves), advancing capabilities to efficiently and non-destructively monitor water content in moss communities becomes a key research priority. Because of the complexity induced by multiple micro-climatic drivers and its fragility, tracking the evolution and responses of moss bed moisture requires monitoring methods that are non-intrusive, efficient, and spatially significant, such as the use of unoccupied aerial systems (UAS). In this study, we combine a multi-species drying laboratory experiment with short-wave infrared (SWIR) spectroscopy analyses to first develop a Random Forest regression Model (RFM) capable of predicting Antarctic moss turf water content (~5% error). The RFM was then applied to UAS-borne SWIR imaging data (900–1700 nm, resolution) of the moss beds at high spatial resolution (2 cm) across three sites in the vicinity of Casey Station, Antarctica. The sites differed in terrain, snow cover, and moisture availability to evaluate method capabilities under different conditions. Optimum RFM parameters and input variables (spectral indices and reflectance spectra) were determined. Maps of moss moisture were validated via acquiring moss spectra and water content (using sponges inserted into the moss turf) collected in situ, for which an exponential correlation (R2 = 0.72) was reported. RFM further allowed investigation of the influential spectral variables to model water content in moss and associated spectral water absorption features. We demonstrated that UAS-borne SWIR imaging is a promising new tool to map and quantify water content in Antarctic moss beds. Hyperspectral mapping facilitates the exploration of the spatial variability of moss health and enables the creation of a baseline against which changes in these moss communities can be measured

Extraction of buildings from high-resolution satellite data and airborne LIDAR

Automatic building extraction is a difficult object recognition problem due to a high complexity of the scene content and the object representation. There is a dilemma to select appropriate building models to be reconstructed; the models have to be generic in order to represent a variety of building shape, whereas they also have to be specific to differentiate buildings from other objects in the scene. Therefore, a scientific challenge of building extraction lies in constructing a framework for modelling building objects with appropriate balance between generic and specific models. This thesis investigates a synergy of IKONOS satellite imagery and airborne LIDAR data, which have recently emerged as powerful remote sensing tools, and aims to develop an automatic system, which delineates building outlines with more complex shape, but by less use of geometric constraints. The method described in this thesis is a two step procedure: building detection and building description. A method of automatic building detection that can separate individual buildings from surrounding features is presented. The process is realized in a hierarchical strategy, where terrain, trees, and building objects are sequentially detected. Major research efforts are made on the development of a LIDAR filtering technique, which automatically detects terrain surfaces from a cloud of 3D laser points. The thesis also proposes a method of building description to automatically reconstruct building boundaries. A building object is generally represented as a mosaic of convex polygons. The first stage is to generate polygonal cues by a recursive intersection of both datadriven and model-driven linear features extracted from IKONOS imagery and LIDAR data. The second stage is to collect relevant polygons comprising the building object and to merge them for reconstructing the building outlines. The developed LIDAR filter was tested in a range of different landforms, and showed good results to meet most of the requirements of DTM generation and building detection. Also, the implemented building extraction system was able to successfully reconstruct the building outlines, and the accuracy of the building extraction is good enough for mapping purposes.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Extraction of buildings from high-resolution satellite data and airborne Lidar

Automatic building extraction is a difficult object recognition problem due to a high complexity of the scene content and the object representation. There is a dilemma to select appropriate building models to be reconstructed; the models have to be generic in order to represent a variety of building shape, whereas they also have to be specific to differentiate buildings from other objects in the scene. Therefore, a scientific challenge of building extraction lies in constructing a framework for modelling building objects with appropriate balance between generic and specific models. This thesis investigates a synergy of IKONOS satellite imagery and airborne LIDAR data, which have recently emerged as powerful remote sensing tools, and aims to develop an automatic system, which delineates building outlines with more complex shape, but by less use of geometric constraints. The method described in this thesis is a two step procedure: building detection and building description. A method of automatic building detection that can separate individual buildings from surrounding features is presented. The process is realized in a hierarchical strategy, where terrain, trees, and building objects are sequentially detected. Major research efforts are made on the development of a LIDAR filtering technique, which automatically detects terrain surfaces from a cloud of 3D laser points. The thesis also proposes a method of building description to automatically reconstruct building boundaries. A building object is generally represented as a mosaic of convex polygons. The first stage is to generate polygonal cues by a recursive intersection of both datadriven and model-driven linear features extracted from IKONOS imagery and LIDAR data. The second stage is to collect relevant polygons comprising the building object and to merge them for reconstructing the building outlines. The developed LIDAR filter was tested in a range of different landforms, and showed good results to meet most of the requirements of DTM generation and building detection. Also, the implemented building extraction system was able to successfully reconstruct the building outlines, and the accuracy of the building extraction is good enough for mapping purposes

Emerging technologies for reef fisheries research and management [held during the 56th annual Gulf and Caribbean Fisheries Institute meeting in Tortola, British Virgin Islands, November 2003]

This publication of the NOAA Professional Paper NMFS Series is the product of a special symposium on “Emerging Technologies for Reef Fisheries Research and Management” held during the 56th annual Gulf and Caribbean Fisheries Institute meeting in Tortola, British Virgin Islands, November 2003. The purpose of this collection is to highlight the diversity of questions and issues in reef fisheries management that are benefiting from applications of technology. Topics cover a wide variety of questions and issues from the study of individual behavior, distribution and abundance of groups and populations, and associations between habitats and fish and shellfish species.(PDF files contains 124 pages.

Air Force Institute of Technology Research Report 2019

This Research Report presents the FY19 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs). Interested individuals may discuss ideas for new research collaborations, potential CRADAs, or research proposals with individual faculty using the contact information in this document

Aeronautical engineering: A continuing bibliography, supplement 125

This bibliography lists 407 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1980

Volcanic Gas Studies by Multi Axis Differential Absorption Spectroscopy

The chemistry of volcanic plumes can give insights into volcanic processes, which could help with improving the forecast of volcanic eruptions and is also of atmospheric relevance as the volcanic source of aerosols and trace gases can have a significant climatic impact. Although both are very important aspects, the chemical processes in volcanic plumes are inadequately understood. In this thesis, measurements by ground based Mini-MAX DOAS systems were carried out to study gas emissions from eight volcanoes. Bromine monoxide (BrO), chlorine monoxide (ClO), chlorine dioxide (OClO), formaldehyde (HCHO) and sulphur dioxide (SO2) abundances were measured. A global volcanic BrO flux of 1.2 - 13 Gg/y was determined. The study was focused on the measurements of BrO and SO2. The ratio between both trace gases was investigated at di®erent volcanic sites, as well as the dependence on the distance to the source and the volcanic activity. Additional attempts were made to distinguish the di®erent summit craters of Mt. Etna. No BrO was detected in proximity of the active vents of the volcanoes. An experimental study of the increase of the BrO/SO2 ratio with the aging plume was also conducted. ClO and OClO were measured in a volcanic plume for the first time. In contrast to BrO, ClO was detected near the volcanic source, and the distance dependency of ClO/SO2 ratio did not exhibit the increase found for the BrO/SO2 ratio. The miniaturized instrument developed in this thesis made possible to determine an SO2 flux (2.2 t/d) for the remote volcano Ollague. The length of the average light path through a volcanic plume and the problems of determining it was discussed. A comparison between an SO2 flux calculation assuming no scattering due to the volcanic plume and an SO2 flux estimating the enhancement of light path by scattering in the plume illustrate the present uncertainty

Understanding the impacts of pour rate on sugar losses from the chopper harvester

Sugar loss from a mechanical harvester is the most significant of all losses in sugarcane production. The pour rate or material flow through the harvester affects the amount of cane loss and extraneous matter (EM) harvested, as well as impacts on crop production in the next season. Cane loss and EM impact on the quantity and quality of crop delivered to the mills, thus influencing the profits of cane growers, harvesting contractors and millers. The aim of this research was to investigate the effects of harvester set up and operation on sugar loss and how this was influenced by different crop nutrient practices. Field work and data collection was conducted in the Bundaberg, Childers and Ingham districts of Queensland during the 2014–16 sugarcane growing seasons. The sites were aligned with pre-existing nutrition trials arranged in a randomised factorial design with four replicates of nitrogen application rates (0–225 N kg/ha). In the plots of interest, the physical properties of the sugarcane including crop density, stalk length and diameter and leaf percentage was measured immediately prior to harvest. The sugarcane was cut by the chopper harvester with three working fan speeds (650, 850 and 1,050 r/min) and three ground speeds (4, 5 and 6 km/h). Billet and EM samples were collected to understand the impact on billet size distribution, billet quality and loss potential. Trash samples were also collected and analysed for sugar loss. The summation of the various components allowed the full assessment of machine impacts on sugar loss, sugarcane quantity and the economic impacts on the three sectors of the sugarcane industry. The results showed that high pour rates (driven in the trials by high N application rates) produced an increased level of EM in the cane billets supplied to the mill and reduced the fan capacity to separate trash from billets. The proportions of damaged and mutilated billets at high pour rates were also elevated due to the difficultly in separating the components by the extractor fan. Conversely, the percentage of sound billets and sugar loss were increased at the low N application as the lighter billets were ejected more easily by the cleaning system than the heavier ones. When the pour rate increased (high ground speed and the fan speed (6 km/h, 1,050 r/min, the commercial cutting setting)), the cane loss and EM were high but the billet supply bulk density decreased. Conversely, operating with the low ground and fan speeds (4 km/h, 650 r/min), the cane loss and the bulk density in the billet supply were reduced but the EM was increased, resulting in low CCS and high transportation cost that reduced the grower’s income. The cutting ground speeds at 4 km/h with 850 r/min of fan speed provided the optimised cutting conditions which were a combination of increased sugar recovery without excessive transport cost. In this situation, the growers’ revenue was increased around 9,700 AU$ per 1,000 t of harvested cane through better CCS and cane supply yield. Under this costing model, the harvesting contractor still achieved a balanced income even with the increased costs during harvesting and transportation. Additionally, the miller received increased returns due to the improved processing performance of the sugar recovery due to the quality of the billet supply (high CCS). Crop parameters change very markedly between and within fields. This research has shown how these changing parameters can dramatically influence the ability of the chopper harvester to efficiently convert grower efforts on farm, to millable sugar at the refinery. The complex relationship between pour rate, ground and fan speed impacts on the profitability of the three sectors in the sugar industry – grower, contractor and miller. Continuously fine-tuning the harvester settings is important to fully optimise the system compared to the current practise of infrequent adjustment