Performance Analysis of SBAS Aided GNSS Positioning

The navigation solution of multi-GNSS can be further improved with help of additional ranging signals from Satellite Based Augmentation systems (SBAS). Apart from ranging, SBAS satellites provide differential corrections and integrity monitoring ability. Several SBAS systems are operational in various parts of the world, such as WAAS (U.S.A), EGNOS (Europe), Beidou (China), MTSAT (Japan) and GAGAN (India) [1]. In the present study the satellite signals of multi -GNSS (GPS, GLONASS and Galileo) along with SBAS satellite signals visible at the GCET station are considered for evaluation of accuracy of the position. The error in the estimated position of GNSS receiver is usually described by terms accuracy and precision. The degree of closeness of an estimate to its true position, which is an unknown value is accuracy and precision is the degree of close of observations to their mean value. To quantify accuracy and precision, 2D-RMS horizontal and vertical error and 3D position error are calculated. The measured accuracy is evaluated instead of formal and predicted accuracy. The standard deviation of position error along x, y and z-axis have to be calculated from the estimates and is given as [2]