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Drift moves aquatic insects downstream, risking depopulation of upstream reaches. However, the necessity and exist­ence of an upstream flight to compensate for drift has not been undisputed. I analysed a sample of approximately 70 000 Trichoptera from a stream in northern Sweden collected during one season in 1974. The overall flight direction was upstream. Females had a stronger upstream flight than males and species varied in both flight direction and strength of the preference. Flight direction was not affected by wind or trap type. Upstream flight varied during the season and with different larval behaviours. Upstream flight increased with the size of the imago and with the abun­dance in flight. A colonisation cycle might be in effect but even though upstream flight occurs, it might not be neces­sary to sustain populations in upstream reaches.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A very restrictive down-range flight area for a small ground-to-air missile required the interruption of the flight after the missile had flown past a specialized target and telemetry data had been transmitted to a receiving station. Explosive bolts separated the missile into two sections and cables loosely attaching the two sections caused the system to tumble and therefore interrupt the flight. Because of the high dynamic forces exerted on the attaching cables, soft material "shock absorbers" were used to assure the integrity of the cables.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents instrumentation and telemetry system techniques used in free-flight research drop model testing at the NASA Langley Research Center. The free-flight drop model test technique is used to conduct flight dynamics research of high performance aircraft using dynamically scaled models. The free-flight drop model flight testing supplements research using computer analysis and wind tunnel testing. The drop models are scaled to approximately 20% of the size of the actual aircraft. This paper presents an introduction to the Free-Flight Drop Model Program which will be followed by a description of the current instrumentation and telemetry systems used at the NASA Langley Research Center, Plum Tree Test Site. The paper describes three telemetry downlinks used to acquire the data, video, and radar tracking information from the model. Also described are two telemetry uplinks, one used to fly the model employing a ground based flight control computer and a second to activate commands for visual tracking and parachute recovery of the model. The paper concludes with a discussion of free-flight drop model instrumentation and telemetry system development currently in progress for future drop model projects at the NASA Langley Research Center.

International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / The GPS Satellite System provides precise determination of time, space, and position of aerospace (airborne) vehicles during flight and flight test situations. The cost of "GPS" equipment has been decreasing dramatically -- a phenomenon similar to that which was experienced with "hand held" calculators 20 years or so ago. By the use of a multigain (and beam) antenna and GPS, a very low cost single axis system can be utilized for reception of telemetry and at the same time to provide accurate position, velocity, and acceleration information concerning the airborne vehicle.

Human performance in spatial orientation tasks is mainly determined by spatial awareness and the skills to transition from the current spatial attitude into the desired spatial orientation and position. Erroneous spatial awareness may lead to degraded task performance, to the loss of equipment, to serious injuries, or fatal aviation mishaps. The use of UAVs is considered beneficial due to the reduction in risk to the human carrying out the "mission". However, the remote execution of such a mission is extremely demanding for the operator. If extensive use of UAVs is to become routine, a number of concerns that may influence their effective use needs to be addressed. When we consider the human-in-the-loop (HITL), then vehicle control and the use of autonomy are important issues for the end user. Therefore this thesis will investigate the use of a virtual avatar in the flight simulator software (Weber Box) and conduct experimental proof of concept (conduct of experiments and analysis, evaluation and validation of the data of the concept using actual flight simulation software). Results of a study (conducted by Weber, 2006) indicated that the proposed design (Weber Box) seemed to strongly support spatial awareness in 3D orientation tasks. Time to assess a spatial situation decreases significantly, whereas accuracy of this spatial judgment at least maintains its level. This study investigated human orientation performance in relation to display designs that support mental models of the user's spatial situation under varying workload conditions. The main goal is to support the pilot/operator with intuitive, 3D-based information which improves their spatial awareness and supports their mental model of spatial position, he/she is operating under, even with varying workload conditions. As a follow-up study has to be identified, determining whether varying workload affects performance between the two display designs, and if there is a significant difference to a set of properties which are essential for linking virtual avatars and spatial awareness.

Simultaneous localization and mapping (SLAM) is the problem of mapping your surroundings while simultaneously localizing yourself in the map. It is an important and active area of research for robotics. In this master thesis two approaches are attempted to reduce the drift which appears over time in SLAM algorithms. The first approach tries 3 different motion models for the camera. Two of the models exploit the a priori knowledge that the camera is mounted on a trolley. These two methods are shown to improve the results. The second approach attempts to reduce the drift by reducing noise in the point cloud data used for mapping. This is done by finding planar surfaces in the point clouds. Median filtering is used as an alternative to compare the result for noise reduction. The planes estimation approach is also shown to reduce the drift, while the median estimation makes it worse. / Simultaneous localization and mapping (SLAM) är problemet att kartlägga sin omgivning samtidigt som man lokaliserar sig själv i kartan. Det är ett viktigt och aktivt forskningsområde inom robotik. I det här exjobbet testas två tillvägagångssätt för att minska felet i kameraposition och orientering som uppstår över tiden i SLAM-lösningar. Det första tillvägagångssättet testar 3 olika rörelsemodeller för kameran. Två av modellerna utnyttjar vetskapen om att kameran sitter monterad på en vagn. Dessa två metoder förbättrar resultatet för SLAM-algoritmen. Det andra tillväggagångssättet försöker minska felet genom att reducera bruset i punktmolnsdatan som används i kartläggningen. Det görs genom att hitta plana ytor i punktmolnen. Medianfiltrering används som en alternativ lösning för att jämföra hur bra planestimeringen står sig. Planestimeringen visar sig också minska felet i lösningen, medan medianfiltreringen endast försämrar resultatet.

This thesis documents a research project in which an autonomous flight control system (FCS) was designed to control and navigate small, high-speed, unmanned, jet-turbine powered fixed-wing aircraft. The FCS was designed to allow the aircraft to maintain controlled flight, and return to a home location, without any operator intervention. The flight control computer was built with an FPGA, using a Microblaze soft-core microprocessor running the uClinux operating system. The configurable FPGA computing platform allowed flexibility for interfacing quickly with a wide range of sensors and control modules. A commercial inertial measurement unit was used for aircraft state estimation, and the flight control system was able to provide stability and precise flight-path control for multiple turbinepowered aircraft over the wide flight airspeed envelope these vehicles are capable of. In addition, the custom ground control station which provides an operator control interface for the FCS is discussed.