چكيده به لاتين
One of the methods of position determination is to use the GPS system. Users can access a single-frequency, low-cost civilian GPS receiver with an 8 to 12 meter real-time positioning error after making regular corrections.One way to increase positioning accuracy and precision is to use DGPS methods, which can improve positioning accuracy from 4 meters to several millimeters depending on their type.But using such systems will cost a lot and create constraints such as additional accessories and distance covered by these services.In this thesis, the combination of raw data of four Low Cost GPS Single Frequency was used to reduce the errors of real-time positioning estimation.The signal-to-noise ratio of the received signal from satellites as well as the number of satellites observed is not the same for similar GPS receivers. The low signal-to-noise ratio and low number of satellites observed reduce the precision and accuracy of real-time positioning.Therefore, the number of high-quality measurements for the whole set is increased by combining GPS multi-receiver raw data and, as a result, positioning accuracy and accuracy can be improved. On the other hand, after regular corrections due to systematic errors, random errors such as noise, and the multipass error received signal from code pseudorange measurements of the Remain code, which reduces positioning accuracy and precision. Estimation methods along with the use of distance constraints between GPS receiver antennas were used to mitigate these errors. Laboratory tests were carried out in the sports field of the University of Science and Technology. The results were compared with the GINTEC G10 triple frequency GPS receiver and it was shown that applying the length restrictions of the distance between GPS receiver antennas in position estimation algorithms improves the accuracy and accuracy of real-time positioning.
Another use of the GPS system is the concern of determining the vehicle's attitude through multi-receiver GPS antennas in the vehicle's body.The most common way to solve this problem is to use double difference measurements in the carrier phase, which enables the relative position vector to be accurately and precisely obtained, but the fundamental challenge of this method is to resolve ambiguity in the real-time carrier phase, especially for the single frequency GPS receiver with low cost. To solve the problem of attitude determination, a method is provided at first to solve the ambiguity of the carrier phase.This method is based in the first epoch on the placement stand by side of GPS antennas. We then used the length constraints and angle constraints between the relative position vectors to improve the accuracy and precision of estimating the relative position vectors. Laboratory tests were performed to determine the art's attitude in the University of Science and Technology's sport field.The results of the experiments indicate that the time of ambiguity resolution is reduced and the carrier phase's ambiguity resolution is close to instantaneous and improves the accuracy and precision of the determination of real-time attitude.
