Assessment of Detection, Identification and Adaptation (DIA) procedure with DGPS considering occurrences of ionospheric bubbles and intense scintillation

Abstract

Ionospheric effects on signals from Global Navigation Satellite Systems are potential threats in cases involving their use for augmentation systems. Such applications require highly accurate positioning, high system availability, integrity, and continuity in any ionospheric condition. A solution typically used is the Differential Global Positioning Systems (DGPS) procedure, that broadcasts corrections for the users around a given reference station. This procedure provides corrections related to ionospheric and tropospheric errors. However, even differential systems, like the Ground Based Augmentation System (GBAS), suffers operating restrictions due to intense ionospheric variations generating delay gradients. Additionally, there are still availability issues that ground receivers may experience due to scintillations. In this work, the performance of DGPS is evaluated during cases of strong ionospheric variations. The emphasis is on the use of Detection, Identification and Adaptation (DIA) technique for quality control. The analysis shows that even in cases when the standard DGPS method is affected due to scintillation, the DIA-based approach remains stable and operational. For 3D errors smaller than 5 meters, the results from DIA indicate reductions of 80% and 2,6% when compared to single point positioning and standard DGPS, respectively. Therefore, the findings of this experiment indicate that, under the conditions considered, the use of the DIA approach in the DGPS might increase the tolerance of this service against the effects of ionospheric delay gradients and scintillation.