Assessment of EGNOS performance for civil aviation flight phase in the edge coverage area

<p>The performances of the navigation systems used for different flight phases especially in the landing of an aircraft must be very high. The International Civil Aviation Organization defines the standards which must meet by any navigation systems to be certified, so it can be used by civil aircraft. To achieve the level of security defined by the International Civil Aviation Organization, new augmentation systems based satellites are developed. In Europe, the EGNOS system was developed to improve both GPS and Galileo performance. In this paper the performance of the EGNOS system for civil aviation flight phase was investigated. Four parameters are taken in consideration “accuracy, degree of confidence, availability and integrity”. The study carried out in this work focus on the evaluation of actual EGNOS status in its coverage area edge. Until now the existing information about this area is based simulation and interpolation from ESA, in this work 5 GPS station are used to evaluate this model; for each sites, position was calculated by GPS alone and by GPS corrected with EGNOS messages. The results obtained from those sites show that the position accuracy is well improved in all the 5 sites, in some case the precision achieve 50%. In the other hand, the three other parameters are respected only for sites above Latitude 34°. The vertical and horizontal protection levels are below 50 and 40 m with a 100% Vertical and Horizontal availability and integrity. The results obtained show that the EGNOS system can be used until the APV I phase without any external help and the implementation of a RIMS station in Algeria can improve significantly the coverage area in all North Africa.</p>