1. Blanch J (2003) Using Kriging to bound satellite ranging errors due to the ionosphere. Ph.D. Dissertation, Stanford University
2. Bunce D (2013) Wide Area Augmentation System (WAAS)—Program Update. In: Proceedings of ION GNSS + 2013, Institute of Navigation, Nashville, TN, September, pp 2299–2326
3. Enge P, Walter T, Pullen S, Kee C, Chao Y, Tsai Y (1996) Wide area augmentation of the global positioning system. Proc IEEE 84(8):1063–1088
4. ESSP (2015) EGNOS Service provision yearly report 2014–2015. European Satellite Service Provider
5. ISRO (2015) Annual report 2014–2015. Indian Space Research Organisation (ISRO), the Republic of India