Desarrollo y evaluación del algoritmo del filtro de Kalman para mejorar la precisión del posicionamiento GPS.

Abstract

The objective of this work was the development and evaluation of the Kalman filter algorithm to improve the positioning accuracy of the GPS system. The errors that most affect the GPS signal are thermal noise, generated by the ionosphere, troposphere, multipath, this is generated when the signal crosses the layers of the Ionosphere and Troposphere in which changes in signal speed are generated and this mainly affects recipients that work in simple frequency; the other errors do not greatly affect the GPS signal but affect the accuracy of the position. The elimination of the different errors was carried out applying the Kalman Filter Algorithm; the information generated by the satellites is stored in a universal format and they are the RINEX files from which the code and the phase of the carrier are extracted; then it is proceded to the download of these files from receiving stations located in the land. With the measurements the differentiation is made in an estimated time generating the signal code less phase to be filtered later allowing obtaining the corrected signal. The values of the stability time of the Kalman filter are in a range of 300 to 1800 seconds, the decrease of the different errors affecting the values of the accuracy is observed. As a conclusion it can be mentioned that the larger the estimated time, there is an improvement in the reduction of errors gradually with respect to the original signal; this applies to single frequency receivers as the solution to the inconvenience generated in the transmission of data. It is recommended that the filter should work with receivers and double frequency techniques to improve the accuracy of GPS positioning.