On the Correlation of Solar Activity and Troposphere on the GNSS/EGNOS Integrity. Fuzzy Logic Approach

Abstract

There is a noticeable number of studies carried out on both the operational parameters of Global Navigation Satellite System (GNSS) and the satellite signal itself. Researchers look for, inter alia, proven sources of errors affecting the integrity of the satellite signal because this parameter determines the approval of the system’s operational use. It also seems of key importance that the atmospheric conditions, in any area of satellite signal usage, should not be underestimated due to their extensive impact. As the ionospheric refraction seriously limits the operational use of the satellite navigation signal, in this article, the authors attempted to quantify the effect of solar activity (expressed by sunspots) on the signal integrity using fuzzy logic. Fuzzy reasoning is used when information is inaccurate or incomplete and necessitates making decisions under conditions of uncertainty. Thanks to fuzzy sets, there are no obstacles to characterize the degree of intensity of a given phenomenon. In order to look at the problem more broadly, attention was also paid to the tropospheric conditions, and it was verified whether, against the background of cloudiness, precipitation, humidity, pressure and temperature, solar activity affects the integrity to the greatest extent. The integrity measurements from the EGNOS system (PRN120 and PRN126) collected at the monitoring station in Warsaw, Poland in 2014 were used.

Examination of Different Models of Troposphere Delays in Sbas Positioning in Aerial Navigation

“…Publication [8] shows the impact of the tropospheric correction model on the algorithm of determining HPL/VPL integrity parameters in SBAS satellite positioning for aerial navigation. Furthermore, the authors of the publication [9] have developed an algorithm for evaluating the influence of troposphere parameters on SBAS navigation signals using fuzzy functions. The troposphere parameter results obtained were related to the state of the ionosphere to determine the levels of reliability in GPS+SBAS positioning.…”

“…Based on the available data, it appears that: -the problem of using an appropriate tropospheric correction model for SBAS positioning is relevant [5], -until now, the problem of determining an appropriate tropospheric correction model has mainly concerned GNSS satellite navigation [6,7,12,13,14], -for SBAS positioning, the tropospheric correction model was included in the calculation of the HPL/VPL integrity parameters [8,9], -a particular SBAS augmentation system should have an appropriate model and an algorithm for determining the tropospheric correction [10,11].…”

Optimal Global Positioning System/European Geostationary Navigation Overlay Service Positioning Model Using Smartphone

“…The main purpose of SBASs (Satellite-Based Augmentation Systems) is to support civil aviation tasks. However, due to their ability to improve the quality parameters of GNSS positioning, they can also have other applications [1][2][3][4]. The operation of SBAS systems relies on the use of geostationary satellites to transmit correction data and other information that can improve GNSS positioning.…”

Application of the Energy Efficiency Mathematical Model to Diagnose Photovoltaic Micro-Systems

“…There have also been studies based on the method of comparing neighbouring systems [22], large-scale dispersion [23] or referring to such numerous, different models [24]. The largest group includes papers describing the diagnosis of photovoltaic systems based on inverter and weather station data using artificial intelligence, particularly machine learning methods [25][26][27][28][29][30][31][32][33][34][35][36]. They are widely discussed in the source literature and usually provide good diagnostic results; however, they require a specific set of training data for each PV system unit.…”