Test and Evaluation of Ionospheric Monitoring Performance for Dongying Shengli Airport

Abstract

El sistema de Aumentación de la señal GNSS basado en tierra (GBAS) puede mejorar la Precisión, Integridad, Continuidad y Disponibilidad de los sistemas de Navegación y Posicionamiento, motivo por el cual es una aplicación muy usada para la Navegación Satelital en la aviación civil. De acuerdo al tipo de performance a ser proporcionado por un proveedor de los servicios de tránsito aéreo se tiene: GAST-C, GAST-D y GAST-F, siendo GAST-F el más preciso y el GAST-C el menos preciso. El factor más determinante para la precisión del sistema GBAS es el efecto de la Ionósfera sobre la señal al desplazarse desde el satélite hasta el receptor, motivo por el cual es crucial contar con un Monitor de Integridad Ionosférica. Este trabajo de investigación realiza la evaluación del monitor de Integridad Ionosférico del sistema GBAS del Aeropuerto Dongying Shengli de China, aplicando los actuales algoritmos para GAST-C, GASTD y GAST-F a las señales recibidas de las constelaciones GPS y BeiDou. Como contribución adicional se presenta el uso del filtro Butterworth para reducir el efecto del multipath de las señales de navegación.

The Ground-Based Augmentation System (GBAS) can improve the Accuracy, Integrity, Continuity and Availability of satellite navigation and positioning, and is a typical application of satellite navigation in the field of civil aviation. According to the Approach Service Type, GBAS performance can be divided into three types: GAST-C, GAST-D and GAST-F from low to high. Ionospheric delay is the main factor affecting GBAS. The main method of mitigating the ionospheric effect in GBAS is to monitor and evaluate the characteristics of the ionosphere through a dedicated monitor. The test and evaluation of the ionospheric monitoring performance in GBAS is the research focus and hot spot in the satellite navigation civil aviation application field. The main contributions of this thesis are as follows: For the ionospheric monitoring in GAST-C, based on the measured data from the GBAS station of Dongying Shengli Airport, through the code carrier divergence (CCD) and carrier Acceleration, RAMP, STEP and other tests, the ionosphere threat was identified and evaluated by the monitor. The results showed that the Ionospheric Delay Gradient and Satellite Clock failure did not appear. For the ionospheric monitoring in GAST-D, and for the higher integrity requirements of the GAST-D system, through the application of Code Minus Carrier (CMC) and second-order Hatch filter, the common term errors are removed, including Satellite and receiver clock errors, tropospheric delay errors, etc. The test results show that the GPS and BDS integrity observations are maintained within the threshold established for the GAST-D system. For the ionospheric monitoring in GAST-F, based on the observation data of GPS L1/L2 and BDS B1/B3, on the basis of implementing the same configuration as GAST-D, the combination of dual-frequency ionosphere-free (IFree) Implement monitoring of layer error items. The test results marked the satellites that were alerted because they did not meet the monitor performance requirements. At the same time, a Butterworth filter is used in the process to reduce the effect of multipath effect errors on the navigation signal.