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Final Final Powerpoint for NSAS by Lawal and Chatwin for Sunshine 2015.pdf (2.25 MB)

Enhancing public safety and security of critical national infrastructure utilizing the Nigerian Satellite Augmentation System (NSAS)

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Version 2 2023-06-12, 06:36
Version 1 2023-06-08, 23:43
posted on 2023-06-12, 06:36 authored by Lasisi S Lawal, Chris ChatwinChris Chatwin
After the First World War, radio time signals offered alternative technology for determination of the Greenwich time and thus longitude at sea. The first manifestation of new technology capable of usurping the super accurate mechanical chronometers occurred in 1904, when the United States Navy began to experiment with the transmission of radio-time signals as an aid to the determination of longitude (Davies, 1978; Lawal & Chatwin, 2011). The challenge in precision continued with precision in Navigation systems, which depends on electromagnetic waves travelling at 300,000,000 m/s, which means that one microsecond error in a vessel’s time will result in 300metres of navigational error. The Global Positioning System (GPS) originated from the Navigation System with Timing and Ranging known as NAVSTAR, which was initiated by the Joint Program Office (JPO) of the U.S. Department of Defence (DoD) in 1973.The first GPS satellite was sent into orbit in 1978. Initial Operational Capability (IOC) was reached in July 1993 with 24 satellites, while Full Operational Capability (FOC) was declared on July, 17th, 1995. Improvement in accuracy for general transportation, especially in aviation, ushered in augmentation systems. The quest for performance focused on the ability to accurately transmit and keep time signals stable up to the picosecond level and even more in receivers and clock reference signals for space systems, especially in navigation satellites using high performance oscillators ranging from ultra-stable quartz crystals with ovenized control to high performance atomic circuits (Lawal & Chatwin, 2011). The Satellite-Based Augmentation System (SBAS) arose from the need to provide continuity, availability, integrity and accuracy of global positioning signals to eliminate errors and compensate for discrepancies associated with GPS signals and other navigation systems. The NigComSat-1R Navigation (L-band) payload is a Space Based Augmentation System meant to provide a Navigation Overlay Service (NOS) similar to the European Geostationary Navigation Overlay Service (EGNOS). This paper describes the huge untapped potential that the hybrid satellite offers in the area of public safety, security of critical national infrastructure, aviation, maritime, defense, effectiveness of Location Based Services for Emergency and Crisis management amongst other applications; it thus fills a great gap in the augmentation systems for Africa.


Publication status

  • Published

File Version

  • Published version

Presentation Type

  • paper

Event name

Sunshine 2015: Annual Conference and AGM of The Nigerian Society of Engineers

Event location

Akure, Ondo State, Nigeria

Event type


Event date

16-20 November 2015

Department affiliated with

  • Engineering and Design Publications

Full text available

  • Yes

Peer reviewed?

  • Yes

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