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I present an application to visualization of GPS data and Linear Correlations and models. A collection of data for each vehicle is used to compute correlations. Deviating correlations can be indicative of a faulty vehicle. The correlation values for each vehicle are computed with use linear regression algorithms using up to 4 signals in the data (with varied time window), and display the model parameters in a window next to the GPS map. Multiple measurements (multiple drive routes and multiple model parameters) are displayed at the same time, allowing tracking over time and comparison of different vehicles. The whole technique is demonstrated on three data which is set on first frame by user. The results are displayed with a java application and Google Map.

In this study, the connection of a local levelling network to the national height system in Sweden, RH 2000, with GNSS-techniques is investigated. The SWEN 08 is applied as geoid model. Essentially, the method is precise normal height determination with GNSS. The accuracy, repeatability and the affecting elements are tested. According to the statistics,the proposed method achieves 1-cm accuracy level. Suggestions on the general methodology and settings of several elements are proposed based on the statistics for the future application.

Recent government regulations for Enhanced 911 locating of wireless handsets require accuracy to within 50 and 300 meters. Two technologies under consideration are triangulation using existing wireless base stations and location using global positioning satellites (GPS). Satellite positioning is the leading candidate, however, reception of GPS signals within large buildings is difficult and considerable research is devoted to this topic. Conventional GPS receivers require line of sight to at least four satellites and, under outdoor conditions, the expected signal level is about -160 dBW. Within large buildings, detection is very difficult because there is high thermal noise and some satellite signals can be attenuated to less than -185 dBW while others can suffer little attenuation. In order to construct the pseudo-ranges necessary for position finding, the receiver must synchronize to the incoming codephase of each satellite and must operate with substantial Doppler frequency offset caused by satellite motion.<p> This thesis investigates the application of a parallel non-coherent spread spectrum synchronizer previously implemented as a very-large-scale integration (VLSI) circuit. The circuit processes one millisecond of incoming signal and uses a segmented matched filter (SMF) by which the segmentation provides some tolerance to Doppler shift. The thesis presents simulation results of averaging for tens of seconds. Through simulation, the SMF is compared with a transversal matched filter (TMF) under conditions of no Doppler shift; coherent and non-coherent integration are discussed. The simulation is conducted at 290 K (17°C) such that the Boltzmann noise is -204 dBW/Hz, with a GPS signal bandwidth of 2 MHz and signal level of -185 dBW, and the receiver input signal-to-noise ratio (SNR) is -44 dB.<p> The SMF is applied using differing segment lengths to high-sensitivity GPS data from indoor and urban simulated GPS data. The results demonstrate the SMFs ability to tolerate Doppler frequency offsets while allowing for long integration times to detect the weak GPS signals.

One of the major impediments to developing a larger body of knowledge in travel behavior than we currently have is the lack of sufficient data at very detailed levels. The lack of sufficient data is the result of the inherent complexity of gathering and subsequently analyzing observations of the phenomena of interest. This is particularly true for route choice, a topic on which scant link-by-link data appear to be available, especially at multi-day level. In fact, very little empirical work is based on real world observation. This dissertation studies the factors that influence morning commuters route choice and route switching based on objective real-world observations of travel behavior during multi-day period. This dissertation tests the current route choice model assumption that travel time or travel distance is the only factor influencing drivers route choice decision. Investigation of the objective route choice factors confirms that minimizing travel time, although very important, is not the only factor that impacts route choice. Several other factors have been identified that impact commuters route choice. This dissertation examines the choice between using single or multiple morning commute routes. The results indicate the strong explanatory power of work schedule flexibility and trip-chaining on the choice of single or multiple commute routes compared to the commuters socio-demographic characteristics and commute route related attributes. This dissertation also presents an extensive effort in analyzing GPS-based travel behavior data and develops a methodology to subtract route choice information and trip-level travel information from the GPS-based vehicle activity data.

The need addressed in this thesis is to provide an Autonomous Ground Vehicle (AGV) with accurate information regarding its position, velocity, and orientation. The system chosen to meet these needs incorporates (1) a differential Global Positioning System, (2) an Inertial Measurement Unit consisting of accelerometers and angular-rate sensors, and (3) a Kalman Filter (KF) to fuse the sensor data. The obstacle avoidance software requires position and orientation to build a global map of obstacles based on the returns of a scanning laser rangefinder. The path control software requires position and velocity. The development of the KF is the major contribution of this thesis. This technology can either be purchased or developed, and, for educational and financial reasons, it was decided to develop instead of purchasing the KF software. This thesis analyzes three different cases of navigation: one-dimensional, two dimensional and three-dimensional (general). Each becomes more complex, and separating them allows a three step progression to reach the general motion solution. Three tests were conducted at the Texas A&M University Riverside campus that demonstrated the accuracy of the solution. Starting from a designated origin, the AGV traveled along the runway and then returned to the same origin within 11 cm along the North axis, 19 cm along the East axis and 8 cm along the Down axis. Also, the vehicle traveled along runway 35R which runs North-South within 0.1°, with the yaw solution consistently within 1° of North or South. The final test was mapping a box onto the origin of the global map, which requires accurate linear and angular position estimates and a correct mapping transformation.

Dissertation (Ph.D.)--Auburn University, 2009. / Abstract. Vita. Includes bibliographic references (p.294-302).

Navigering med UAV:er kräver att farkostens och eventuellt ett måls position går att mäta ut under flygtillfället. I det allra flesta fall önskas en så hög noggrannhet som möjligt på positionen. DECCA är ett pensionerat system som var konstruerat för att läsa av fasförändringar mellan multiplar av en grundfrekvens. Systemet hade analoga mätare som gav utslag på förändringen av fasen och positionen kunde mätas ut på speciella kartor med inteferenslinjer som motsvarade en viss fasskillnad. GPS ger idag en precision ner på ett par meter, men med optimeringstekniker DGPS går det att komma ner i centimeternoggrannhet. Förutsättningen är att UAV:en befinner sig i ett geografiskt område med en minimal propagering på GPS-signalen. GPS är ett system som används idag och som fortfarande utvecklas. Fokus har lagts på att beskriva hur GPS går till väga för att få en hög precision på positioneringen och med de svårigheter som uppkommer med de långa avstånden mellan mottagaren och satelliten. En kort beskrivning över DECCA-systemets svagheter och styrkor ges, samt en kort sammanställning över hur DECCA och GPS skulle prestera i ett system med sändande antenner utplacerade över ett mindre geografisk område. / UAV navigation requires that the position of the vehicle and perhaps the destination to be measured, in flight. The reliability of close accuracy are in most case crucial for a positioning system. DECCA was constructed to measure the phase differences between several broadcasting frequencies, where all origin from one same fundamental frequency and broadcast as multiples of the source frequency. The system had analog meters which indicated the phase differences and with different interference lines corresponding to a certain phase different printed on a map, one could denote a rough position for the receiver. Today’s GPS grants accuracy within a few meter, but with technology as DGPS the precision can extend to a few centimetres. The condition for the precise position is where the GPS-signal are exposed for minimal propagation effects. Thus, the crucial is the receiver’s geographic location. Today GPS is active and used by numerous user around the world, but it is constant under development and improvement. The focal point has been to describe how GPS gets a good accuracy and the difficulties with the long distances between receiver and satellite. A short description over the weakness and strengths in DECCA has been made. And one short compilation over how well DECCA and GPS would perform in a system with multiple broadcast antennas, placed over a limited geographic area.

Objectives 1. To determine drug misusers' views about their primary health care and their relationship with general practitioners. 2. To undertake a controlled evaluation of small group education of general practitioners in the management of drug misusers. Method 1. Drug misusers attending five treatment services in north east London - a general practice with a special interest in managing drug misuse; a private drug clinic; a community drug team; a drug dependence unit and a street agency - were interviewed using a semi-structured interview and the Social Functioning Questionnaire. 2. All general practitioners who practised within the former North East Thames Regional Health Authority were approached to take part in small group teaching about drug misuse. This was conducted over two consecutive afternoons in a general practice, with four follow-up seminars. The trained doctors were compared with two groups of untrained general practitioners. Outcome measures included: Drug Training Questionnaire responses at the outset and 9 months after training; evaluation of the training appraised on a ten point Likert scale; Home Office Addicts Index and North Thames Regional Drug Misuse Database figures for notification of newly presenting subjects, for each of the three groups of general practitioners, 8 months prior to training and 8 and 16 months after training. Results Ninety percent of the drug misusers were registered with a non-specialist general practitioner and 88% of these doctors were aware of their patients' drug use. Half of the non-specialist general practitioners aware of their patient's drug use were reported as prescribing substitute medication. Sixty percent of misusers attending the non-specialist doctors perceived their general practitioners to hold negative or neutral views about them. Doctors in the specialist general practice were more likely to prescribe, compared to the other four centres, and 97% of their patients believed these doctors had a positive view of drug misusers. The specialist general practice was more active in providing counselling and/or education about drug misuse. 2. Forty doctors attended the teaching programme. Twenty-eight doctors comprised comparison group one (interested but unable to attend the teaching) and 30 formed comparison group two(not interested in training but completed questionnaires). The about to be trained group were seeing and treating more drug misusers compared to the comparison groups. The overall ratings for the teaching programme were high (7.9 for usefulness and 8.0 for interest - maximum score 10). Doctors in the trained group were found to be notifying significantly more drug misusers to the Home Office and prescribing methadone more frequent1y 16 months after the teaching, than doctors in the comparison groups. Over 9 months, the Drug Training Questionnaires demonstrated no significant changes. The cost of the course per doctor was £127. Conclusions 1. The majority of drug misusers attending treatment centres are registered with general practitioners and regarded them as an important health resource in managing both their drug use and wider medical issues, despite the reluctance of non-specialist general practitioners to be involved in prescribing and a high prevalence of unfavourable attitudes towards drug misusers. 2. The participating doctors assessed the teaching programme positively and it was relatively cheap to run. The self-report questionnaires as a single determinant of outcome revealed no significant change in attitudes, knowledge or behaviour but when assessed by more objective means, demonstrated a rise in notification rates and methadone prescribing by the trained doctors.

The vulnerability of GPS to interference has been a major concern for both military and civilian applications, including small UAVs. Various signal processing techniques have been developed to improve the reliability of GPS receivers against different types of interference. Among these techniques, null steering is recognized as an effective method to protect GPS against both narrowband and broadband interference. However, due to the requirement of multiple antenna channels, it has mainly been implemented for large platform applications. This thesis examines the suitability of null steering techniques for small UAV applications and determines the practically achievable anti-jamming ability by implementing a two-element miniaturized adaptive antenna array. The adaptive antenna array is tested against a 2MHz broadband jamming signal under both laboratory testing conditions and a real jamming environment. Approximately 40dB anti-jamming range was achieved in the laboratory testing conditions. 38dB and 42dB were obtained in a real jamming environment with different antenna configuration. The likely performance limitations and possible further performance enhancements are also outlined in this thesis. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1363608 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Electrical and Electronic Engineering, 2008