• Lasisi Salami Lawal Federal University of Technology, Minna
  • Chris Reginald Chatwin University of Sussex
Keywords: Brexit, Communications Satellite, Defence, European Union (EU), Galileo, GNSS, Military, Precision Point Positioning, SBAS.


United Kingdom’s Brexit from the European Union implies restricted access to the European Global Navigation Satellite System (GNSS) System - Galileo; with no access to the secured and encrypted signal used for defense and government purposes, which is restricted to European Union (EU) members. To mitigate this issue, the United Kingdom can, as a matter of urgency, launch a payload on a national military Communications Satellite to provide Navigation Overlay Services for the United Kingdom territory, surrounding waters and neighboring ally countries to meet the requirements of: Defense systems, Aviation, Maritime requirements and the effectiveness of Location-based Services for Emergencies and Crisis management etc. This paper describes the design of a navigation overlay service system as a hoisted payload on a national satellite and the required supporting ground infrastructure, highlighting various applications, services and solutions.


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Author Biography

Chris Reginald Chatwin, University of Sussex

Professor, Senate Member and Convener, Engineering and Design, School of Engineering and Informatics, University of Sussex


Banerjee, P. (2015). Timing in GNSS-Its Importance and Challenges. International Conference on Microwave and Photonics (ICMAP). Doi: 10.1109/ICMAP.2015.7408747.
Cospas –Sarsat (2019). An overview of COSPAS-SARSAT System. Retrieved on 9th January, 2019
Dana, P.H. (1999). The Global Positioning System Overview: The Geographer’s Craft. Retrieved on 8th September, 2009 from:
Davies, A.C. (1978). The life and death of a scientific instrument: The marine chronometer, 1770-1920. Annals of Science, 35(5), 509-525. doi: 10.1080/00033797800200391 Retrieved on 7th January, 2019 from:
Engel, U. (2008). Improving Position Accuracy by Combined Processing of Galileo and GPS Satellite Signals. 11th International Conference on Information Fusion (1-8).
European GSA (2017, April 5th), SAR Success Stories. Retrieved on 14th January 2019 from

Galileo. (2019, January 7). The European Global Navigation Satellite System. Retrieved on 7th January, 2019 from:
Gao, G.X., & Enge, P. (2012). How Many GNSS Satellites are too many?. IEEE Transactions on Aerospace and Electronic Systems, 48(4), 2865-2874.

Gregory, T.F. (1996). Understanding the GPS: An introduction to the Global Positioning System.
John, R.V. (1992). Introduction to Quartz Frequency Standards. Research and Development Technical Report, Army Research Laboratory, SLCET-TR-92-1 (Rev. 1) Retrieved on 16th August, 2009 from :
Jonathan, A. (2018, August 28). Galileo: Brexit funds released for sat-nav study [BBC Science Correspondent Report]. Retrieved on 14th January, 2019 from
Kowoma. (2009, April 19). The GPS System. Retrieved on 19th April, 2009 from:
Lawal, L.S., & Chatwin, C.R. (2011). Essential Parameters of Space-Borne Oscillators That Ensures Performance of Satellite-Based Augmentation System. Proceedings of 3rd IEEE International Conference on Science and Technology, ICAST, (pp42-50). Abuja-Nigeria. doi: 10.1109/ICASTech.2011.6145156.
Lawal, L.S & Chatwin, C.R. (2014). Emergency Communication Preparedness in Africa Exploiting Communication Satellites. Global Space Applications Conference (GLAC) by International Astronautical Federation (IAF) and United Nations Educational, Scientific and Cultural Organization (UNESCO) on 2-4 June, 2014 at UNESCO HQ, Paris, France. Retrieved on 5th June, 2014 from
Lawal, L.S & Chatwin, C.R. (2015). Enhancing Public Safety and Security of Critical National Infrastructure Utilizing the Nigerian Satellite Augmentation System (NSAS). 2015 National Engineering Conference and Annual General Meeting of Nigerian Society of Engineers (NSE) on 16-20 November, 2015 at Akure, Ondo State, Nigeria.
Lawal, L.S & Chatwin, C.R. (2017). Criticality of Space Based Oscillators for the Optimal Performance of Time-Based Signals, Asian Journal of Physics. pp. 1-30. ISSN 0971-3093. Retrieved on 6th January, 2019 from
Meng, X., Roberts W.G., Dodson, A.H., Ince, S., & Waugh, S. (2006). GNSS for Structural Deformation and Deflection Monitoring: Implementation and Data Analysis. 3rd IAG / 12th FIG Symposium held May 22-24, 2006 at Baden.
NigComSat-1R. (2009). Preliminary Design Review (PDR) and Critical Design Review (CDR) of NIGCOMSAT-1R Communications Satellite Project. Nigerian Communications Satellite Limited. Abuja, Nigeria: NIGCOMSAT-1R.
Parkinson, B.W., & Spilker, J.J. (1996). Global Positioning System: Theory and Applications. Volume I.
Quilan, M. (2005). Galileo- A European Global Satellite Navigation System. The IEE Seminar on New Development and Opportunities in Global Navigation Satellite System. Doi: 10.1049/ic:20050558.
Reza, Z., & Buehrer, R. M. (2012). Overview of Global Navigation Satellite Systems. Handbook of Position Location: Theory, Practice, and Advances, First Edition: John Wiley & Sons, Inc, 923-974. Doi:1002/9781118104750.Ch28
Vig, J.R. (2007). Quartz Crystal Resonators and Oscillators for Frequency Control and Timing Applications, (Rev Retrieved on 13th June, 2011 from :
Xu, Y., Lui, H., Zhang, Y., & Feng, Y. (2012). Study on the positional Stability of GPS Reference Stations in TJCORS. China Satellite Navigation Conference (CSNC) 2012 Proceedings, Lecture Notes in Electrical Engineering 159, DOI: 10.1007/978-3-642-29187-6_19.
Zhang, R., Liu, H., Shu, B., Qian, C., & Zhang, M. (2015). Study on Time Transfer using BDS Carrier Phase Observations. Proceedings of the 28th International Technical Meeting of the ION Satellite Division, ION Mallette, L.A., Rochat, P., & White, J. (2008). An Introduction to Satellite Based Atomic Frequency Standards. IEEE Aerospace Conference, (1-9). Doi: 10.1109/AERO.2008.4526366