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This paper proposes an alternative to the conventional public transport tracking systems which uses GPS. The proposed model uses LoRa wireless transmission to communicate between the bus stops and a base station. The buses are equipped with RF transmitters, which sends out data regarding the bus identity, continuously. RF receivers placed in the bus stop, detects this bus when it is in range, and...
This paper presents a dual-channel GNSS receiver covering GPS and Beidou on a single chip in 0.13μm CMOS process. The receiver incorporates one reconfigurable RF front-end and two separate IF signal channels with one single fractional-N frequency synthesizer by using a ring voltage-controlled oscillator. This architecture supports an external active or passive antenna and provides the benefits of...
In this paper, we propose a new positioning method by using wireless local area network systems based on a principle of the Real Time Kinematic-Global Positioning Systems (RTK-GPS). The proposed method collects observations of the carrier phase at access points for double phase difference of the RTK-GPS by following the point coordination function of the IEEE 802.11 standard. We show some numerical...
Wireless communication technology is spreading rapidly to all areas of our lives. The technology, which has a wide range of applications from radios, intelligent home systems, automation applications to GPS units, was used in monitoring the workers working in mines in this study. Most of the mining area underground mining is risky and the possibility of accident (gas jams, the explosion and dents,...
Although a number of asynchronous physical-layer network coding (PNC) schemes have been proposed, synchronous PNC may still be preferred for its simplicity. In this paper we propose a new symbol-level synchronization scheme which reduces the misalignment to less than one hardware clock cycle period. In addition, we prototype the proposed scheme on the Universal Software Radio Peripheral (USRP) platform...
We develop Bayesian algorithms to perform realtime positioning and uncertainty quantification on Global Positioning System (GPS) data. We test the algorithms on GPS data from several global locations and score their predictions using the log-score. The best algorithm is a Kalman filter that assumes an Ornstein-Uhlenbeck (OU) noise model. The OU model accounts for the observed autocorrelated process-noise...
During the last few years, there has been a rise in the use of nanosatellites because they offer a low cost and short development time alternative to larger satellites intended for long-duration missions. The use of commercial components (COTS) instead of the expensive space-grade components required for long missions is one of the main reasons of the popularity of the nanosatellites. This paper presents...
Typical Global Positioning System (GPS) receivers, which are increasingly used in many areas, consume too much energy due to heavy processing in a long time. This makes them not useful and sometimes even impractical for applications with high mobility or operating in obstructed regions where the GPS signal is present in short time. To address the problem, we propose a new design for a fast GPS receiver...
In recent years, GPS has been widely used as a positioning system using satellites. However, GPS receivers cannot position calculation their own positions when they can watch less than three Satellites directly. Therefore, in an environment where there are many obstacles such as urban area, there is a problem that it may be not possible to receive four or more GPS signals from GPS satellites. In this...
Detection and repair of cycle slips is the prerequisite for high precision positioning. This paper proposes a method uses modified MW combination and ionospheric combination. The multipath of MW combination is filtered and then the ionospheric combination is used. This method is able to detect small cycle slips and various combinations of cycle slips. This paper takes experiment on three kinds of...
Recently, utilization of position information by global navigation satellite system (GNSS) is expected in various fields. However, it's difficult to show unambiguously accuracy since positioning accuracy varies by measurement environment. We bring sky view factor (SVF) to evaluation of positioning accuracy, and evaluate it positioning accuracy of long time data in the places where SVF are high or...
Recent smart devices offer technologies that can measure indoor as well as outdoor locations. In the case of outdoor positioning, a global positioning system (GPS) is generally used. There is a limit to the method of using the GPS signal for indoor positioning. A typical indoor positioning method is to use a beacon based on bluetooth low energy (BLE). However, this method has disadvantages that needs...
Satellite selection is an important technology in Global Navigation Satellite Systems (GNSS), for which the dilution of precision (DOP) serves as the key performance metric. Selecting a satellites set with lower DOP often results more accurate positioning and timing. In this paper, the characteristics of DOP for dual-GNSS constellations is studied, where an uncertain clock offset is assumed between...
After analyzing the shortcomings of existing synchronization methods based on GPS and the research status of synchronization for Crosswell Electromagnetic Imaging Logging Tool(CEMIT), a feasible synchronization method combined the actual conditions of CEMIT with the basis of existing research is proposed. First of all, GPS receiver provides a high accurate 1PPS, which received by Surface System, and...
Aiming at the demand for precise positioning of underwater device in marine controllable source electromagnetic (CSEM) exploration system, an underwater acoustic positioning method with one shipborne interrogator and two GPS buoys is proposed. Using numerical simulation method, the influence of ranging deviation and attitude angle deviation on the system positioning accuracy is studied. The simulation...
In order to realize the rapid satellite selection of BDS / GPS dual-mode navigation system under the premise of satisfying the normal positioning accuracy, a new fast satellite selection algorithm is proposed. The algorithm combines the traditional satellite selection algorithm with genetic algorithm. The satellite area is divided by the elevation angles information of the visible satellite, according...
In the integrated navigation system, the carrier phase has higher accuracy than the pseudo-range, but it has the problem of the solution of integer ambiguity. This paper proposes a GPS/INS integrated navigation algorithm based on the double-difference of time/inter-satellite with carrier phase. First, the algorithm is used to eliminate the influence of ambiguity by the simplified time-differenced...
In order to promote the popularization of BDS, the BDS / GPS dual-mode positioning is studied, and the pseudorange single point positioning algorithm of the dual-mode system is analyzed. On the basis of the least squares method, the weighted method is used to improve the accuracy of the positioning solution, and a fixed weight method combining the elevation angle model and posterior variance estimation...
The paper explores the shadows created by moving humans in two types of Forward Scatter (FS) systems, which use GPS signals and sound signals. The comparative analysis of results is based on the correlation analysis and focused on establishing of relationships between different types of shadows. The results show whether it is possible to use sound barriers for detection of moving objects.
The paper introduces a design of radio spectrography receiver that shall serve as equipment for reception, monitoring, and processing of solar radio bursts. These burst can affect operation of many radio communication and navigation services as is presented on example of GPS satellites signal degradation. The concept and design of the spectrography receiver is presented together with discussion of...
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