Desarrollo e implementación del algoritmo del filtro de Hatch en orden de suavizar los errores de las medidas de GPS para mejorar la precisión del posicionamiento estandar.

Abstract

This work aimed to the development and implementation of the Hatch Filter to smooth the errors produced in the standard positioning of the global positioning system (GPS). The error that most affects the signal of the GPS is the one introduced by the ionosphere due to the perturbation that the signal undergoes when crossing this layer, the distortion that causes the refraction affects mainly to receivers that work in simple frequency; there are also uncorrelated errors such as the multipath that influence and impact the accuracy of the position. To eliminate the error introduced by the ionosphere, the Hatch Filter technique was applied; the information generated by the satellites is stored in RINEX File where two measurements are extracted the code-phase and the carrier-phase , these files are downloaded from the receiving stations located on the ground. With the measurements generated from the code-phase and carrier-phase differentiation was performed in an estimated time generating the code signal minus phase called (CMC) to later be filtered allowing to obtain the CMC-Smoothed signal. The values that the attenuation constant takes is in the range of 100 to 500 seconds, the decrease of the error and giving a stability to the signal since it is verified the suppression of the peaks that represent the values affected by the ionospheric error due to its correlation among measurements. It is concluded that the longer the estimated time improves the greater the stability of the constant of attenuation and it is possible to observe the reduction of the errors gradually with respect to the original signal, this applies to receivers of simple frequency as solution to the inconvenient generated in the transmition of data. It is recommended that the filter be extended to work with receivers and dual-frequency techniques to improve the accuracy of GPS positioning.