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1	3D-visualization of fairway margins, vessel hull versus depth data Genel, Kerim, Andersson, Jörgen January 2007 (has links) <p>Fledermaus is software where different kind of analysis with spatial data can be done. The main area where to use Fledermaus is related to hydrographical surveys. This study is aimed to test and analyse the way Swedish Maritime Administration (Sjöfartsverket) uses Fledermaus. Through step by step explaining how to do when measuring sea bed conditions from a vessel, this text is possible to use as a manual for the applications that are mentioned in this report.</p><p>Another thing that is treated is the squat effect that belongs to vessel dynamic motions. Test of visualization that concerning squat in Fledermaus is done, but with a negative result when squat in a perspective to show motions in height that can be up to about a metre is very hard in a terrain model of thousands of metres. By further tests by arranging the input data, several interesting diagrams have been created through Microsoft Excel where graphs show that the depths are affecting the squat effect. This is showed in same diagram but with two different scales to show the relationship between how a point at the vessel moves in height compared to the depth under the vessel when the vessel is navigating in the sea.</p> / <p>Fledermaus är en programvara där olika analyser med rumsliga data kan genomföras. Största användningsområdet är att använda Fledermaus till mätningar som är relaterade till sjömätning. Den här studien är inriktad till att testa och analysera applikationer som Sjöfartsverket använder sig av i Fledermaus. Genom att steg för steg förklara hur Fledermaus ska användas när bottenförhållanden ska mätas sett från ett fartyg, så blir texten även möjlig att använda som en manual till de applikationer i Fledermaus som är nämnda i denna rapport.</p><p>Det andra som behandlas är squateffekten som tillhör ett fartygs dynamiska rörelser. Test av visualisering som behandlar squat i Fledermaus är genomförd, dock med negativt resultat då squat i ett perspektiv med att visa rörelser i höjd som kan uppgå till runt en meter är väldigt svårt i en terrängmodell som sträcker sig tusentals meter. Dock genom vidare tester genom behandling av indata, har flertalet intressanta diagram skapats genom Microsoft Excel där kurvor visar att djupet inverkar på squateffekten. Detta visas genom att i samma diagram fast med två olika skalor visa förhållandet mellan hur en punkt på båten rör sig i höjd jämfört med att djupet under fartyget ändras då fartyget gör fart genom vattnet.</p> Squat Fledermaus 3D-visualization vessel GPS RTK-GPS Multibeam Sonar Surveying Lantmäteri
2	3D-visualization of fairway margins, vessel hull versus depth data Genel, Kerim, Andersson, Jörgen January 2007 (has links) Fledermaus is software where different kind of analysis with spatial data can be done. The main area where to use Fledermaus is related to hydrographical surveys. This study is aimed to test and analyse the way Swedish Maritime Administration (Sjöfartsverket) uses Fledermaus. Through step by step explaining how to do when measuring sea bed conditions from a vessel, this text is possible to use as a manual for the applications that are mentioned in this report. Another thing that is treated is the squat effect that belongs to vessel dynamic motions. Test of visualization that concerning squat in Fledermaus is done, but with a negative result when squat in a perspective to show motions in height that can be up to about a metre is very hard in a terrain model of thousands of metres. By further tests by arranging the input data, several interesting diagrams have been created through Microsoft Excel where graphs show that the depths are affecting the squat effect. This is showed in same diagram but with two different scales to show the relationship between how a point at the vessel moves in height compared to the depth under the vessel when the vessel is navigating in the sea. / Fledermaus är en programvara där olika analyser med rumsliga data kan genomföras. Största användningsområdet är att använda Fledermaus till mätningar som är relaterade till sjömätning. Den här studien är inriktad till att testa och analysera applikationer som Sjöfartsverket använder sig av i Fledermaus. Genom att steg för steg förklara hur Fledermaus ska användas när bottenförhållanden ska mätas sett från ett fartyg, så blir texten även möjlig att använda som en manual till de applikationer i Fledermaus som är nämnda i denna rapport. Det andra som behandlas är squateffekten som tillhör ett fartygs dynamiska rörelser. Test av visualisering som behandlar squat i Fledermaus är genomförd, dock med negativt resultat då squat i ett perspektiv med att visa rörelser i höjd som kan uppgå till runt en meter är väldigt svårt i en terrängmodell som sträcker sig tusentals meter. Dock genom vidare tester genom behandling av indata, har flertalet intressanta diagram skapats genom Microsoft Excel där kurvor visar att djupet inverkar på squateffekten. Detta visas genom att i samma diagram fast med två olika skalor visa förhållandet mellan hur en punkt på båten rör sig i höjd jämfört med att djupet under fartyget ändras då fartyget gör fart genom vattnet. Squat Fledermaus 3D-visualization vessel GPS RTK-GPS Multibeam Sonar Surveying Lantmäteri
3	HANDHELD LIDAR ODOMETRY ESTIMATION AND MAPPING SYSTEM Holmqvist, Niclas January 2018 (has links) Ego-motion sensors are commonly used for pose estimation in Simultaneous Localization And Mapping (SLAM) algorithms. Inertial Measurement Units (IMUs) are popular sensors but suffer from integration drift over longer time scales. To remedy the drift they are often used in combination with additional sensors, such as a LiDAR. Pose estimation is used when scans, produced by these additional sensors, are being matched. The matching of scans can be computationally heavy as one scan can contain millions of data points. Methods exist to simplify the problem of finding the relative pose between sensor data, such as the Normal Distribution Transform SLAM algorithm. The algorithm separates the point cloud data into a voxelgrid and represent each voxel as a normal distribution, effectively decreasing the amount of data points. Registration is based on a function which converges to a minimum. Sub-optimal conditions can cause the function to converge at a local minimum. To remedy this problem this thesis explores the benefits of combining IMU sensor data to estimate the pose to be used in the NDT SLAM algorithm. SLAM NDT Normal Distribution Transform Robotics IMU LiDAR GPS RTK-GPS ego-motion pose estimation Embedded Systems Inbäddad systemteknik Robotics Robotteknik och automation Signal Processing Signalbehandling
4	VBS-RTK GPS輔助UAV影像自率光束法空三平差之研究 / VBS-RTK GPS Supported Self-Calibration Bundle Adjustment for Aerial Triangulation of Unmanned Aerial Vehicle Images 李敏瑜, Li, Min Yu Unknown Date (has links) 無人飛行載具(Unmanned Aerial Vehicle, UAV)於要求精度之圖資測製應用時，因飛行高度較低並可在雲下飛行取像，與大型載具相比可更機動性獲取空間解析度較高之影像，雖無法如大型載具酬載大像幅感測器供大區域圖資製作，但於小區域之圖資更新卻相當適合。但一般UAV因酬載重量限制，僅可酬載體積小且重量輕之感測器，如非量測型相機及低精度定位定向系統，即AHRS系統。因此，本研究嘗試在UAV上酬載Trimble BD970 GNSS OEM GPS接收模組，此GPS接收模組體積小且重量輕可安置於UAV上，並透過VBS-RTK GPS定位技術獲取UAV精確飛行軌跡資訊，再經時間內插相機曝光瞬時的GPS資訊供空中控制使用，輔助UAV影像空中三角測量(簡稱空三)平差，以降低地面控制點需求。但欲引入GPS觀測量供空中控制使用必須考量GPS天線與相機投影中心偏移量之問題，但因UAV所酬載之非量測型相機，將造成此偏移量不易透過地面測量方式測得，於本研究將於空三平差時使用線性漂移參數克服此偏移量無法量測之問題；此外，UAV所酬載之非量測型相機，相機參數乃透過地面近景攝影測量以自率光束法平差方式率定所得，但率定所得相機參數無法完全描述相機在航拍取像時的情況，故本研究於空三平差將採用自率光束法克服相機參數率定不完全之問題。實驗中，首先確定GPS模組BD970在VBS-RTK GPS定位技術下在地面高速移動時可獲得高精度的定位成果；接續驗證線性漂移參數及自率光束法平差於此研究的適用性；最後亦探討不同地面控制點配置及來源對空三平差之精度探討，並提出1/5000基本圖圖資測製精度要求下，VBS-RTK GPS輔助UAV影像自率光束法空三平差的地面控制點最適配置。 / UAV(Unmanned Aerial Vehicle) is currently used in civil purpose such as mapping and disaster monitoring. One of UAV advantages is to collect images with high resolution for mapping demand. However, due to payload limitations of UAV, it is difficult to mount metric aerial camera and precise POS(Positioning and Orientation System) device. Instead, only the non-metric camera and the low accurate AHRS (Attitude and Heading Reference System) can be installed. For mapping demands, Trimble BD970 GNSS OEM board will be carried on the UAV to collect the high accurate flying trajectory as control information for AT (aerial triangulation) by VBS-RTK(Virtual Base Station - Real Time Kinematic) GPS technique. Meanwhile self-calibration bundle adjustment will be employed for AT(Aerial Triangulation) to overcome the imperfect calibration of non-metric camera by the close-range photogrammetric approach. The precise offset between image perspective center and GPS antenna center, called GPS antenna-camera offset, is hard to measure in centimenter level by terrestrial measurement approach. Therefore the drift parameters will be utilized to solve the problem of GPS antenna-camera offset while performing bundle adjustment with self-calibration for AT of UAV images. In the experiments of this study, the height positioning accuracy of BD970 by VBS-RTK GPS approach at high speed movement will be proved firstly. Then the adaptability of drift parameters and self-calibration for GPS supported AT of UAV images will be verified. Finally, the accuracy of AT by using different control information will be analized and appropriate configuration of GCPs(Ground Control Points) for VBS-RTK GPS supported self-calibration bundle adjustment for AT of UAV images will be proposed under the mapping demand with the scale of 1 : 5000. 無人飛行載具虛擬基準站即時動態定位線性漂移參數自率光束法空三平差 UAV VBS-RTK GPS drift parameter self-calibration bundle adjustment aerial triangulation
5	Oceanographic Considerations for the Management and Protection of Surfing Breaks Scarfe, Bradley Edward January 2008 (has links) Although the physical characteristics of surfing breaks are well described in the literature, there is little specific research on surfing and coastal management. Such research is required because coastal engineering has had significant impacts to surfing breaks, both positive and negative. Strategic planning and environmental impact assessment methods, a central tenet of integrated coastal zone management (ICZM), are recommended by this thesis to maximise surfing amenities. The research reported here identifies key oceanographic considerations required for ICZM around surfing breaks including: surfing wave parameters; surfing break components; relationship between surfer skill, surfing manoeuvre type and wave parameters; wind effects on waves; currents; geomorphic surfing break categorisation; beach-state and morphology; and offshore wave transformations. Key coastal activities that can have impacts to surfing breaks are identified. Environmental data types to consider during coastal studies around surfing breaks are presented and geographic information systems (GIS) are used to manage and interpret such information. To monitor surfing breaks, a shallow water multibeam echo sounding system was utilised and a RTK GPS water level correction and hydrographic GIS methodology developed. Including surfing in coastal management requires coastal engineering solutions that incorporate surfing. As an example, the efficacy of the artificial surfing reef (ASR) at Mount Maunganui, New Zealand, was evaluated. GIS, multibeam echo soundings, oceanographic measurements, photography, and wave modelling were all applied to monitor sea floor morphology around the reef. Results showed that the beach-state has more cellular circulation since the reef was installed, and a groin effect on the offshore bar was caused by the structure within the monitoring period, trapping sediment updrift and eroding sediment downdrift. No identifiable shoreline salient was observed. Landward of the reef, a scour hole ~3 times the surface area of the reef has formed. The current literature on ASRs has primarily focused on reef shape and its role in creating surfing waves. However, this study suggests that impacts to the offshore bar, beach-state, scour hole and surf zone hydrodynamics should all be included in future surfing reef designs. More real world reef studies, including ongoing monitoring of existing surfing reefs are required to validate theoretical concepts in the published literature. Aramoana Beach Dunedin (New Zealand) ArcGIS ArcSDE artificial surfing reef backscatter Baseline Data Collection bathymetry bathymetric surveying beach morphodynamics beach-state and morphology breaking wave height coastal engineering coastal environment coastal management coastal monitoring coastal processes coastal structures currents economic value EIA environmental data management environmental impact assessment geographic information systems geoid geomorphic surfing break categorisation GIS groin hydrodynamic modelling hydrographic surveying hydrography ICZM incline plane modelling integrated coastal zone management Main Beach Mount Maunganui (New Zealand) Manu Bay Boat Ramp Raglan (New Zealand) measuring water levels morphological coupling multibeam echo soundings oceanography offshore wave transformations Palm Beach Reefs Gold Coast (Australia) RTK GPS salient surf zone hydrodynamics surfing break components surfing reefs surfing tourism surfing wave climate surfing wave parameters Tay Street Mount Maunganui (New Zealand) wave breaking intensity wave climate wave focusing wave modelling wave peel angle wave section length wind effects on waves

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