Study of GNSS Parameters and Environmental Factors over Bangladesh Intended for Selecting Ideal Ground Station Location for SBAS

For precise positioning, augmentation of the navigation system has gained widespread recognition and most of the countries have opted for developing local satellite based augmentation system (SBAS). To operate the overall system seamlessly, it is crucial to select ground station locations from which the system can be monitored and communication with the satellites can be performed. Since the atmospheric condition and the number of in view satellites are not similar, the performance of the GNSS signal parameters also vary. The atmospheric conditions that dominate the overall performance are temperature, humidity, rain rate, total electron count etc. Not only that the troposphere and ionosphere also play a key role in signal propagation delay. So it is essential to estimate the effects of the parameters for different location to have a comparative analysis utilizing existing models. In this paper, five major cities of Bangladesh are surveyed for a longer period of time to find out the assessment in terms of some GNSS parameter as well as atmospheric delay. The troposphere scintillation fade depth (SFD) and rainfall attenuation are estimated utilizing ITU-R model whereas ionospheric delay is calculated using Klobuchar model. The overall analysis is done with two satellite constellation frequencies - GPS (L1) and Galileo (E5) to observe the variation in results.