GPS World, November 2018

ENTER THE BINONAV An Alternative to GNSS for Maritime Positioning 42 GPS WORLD WWW GPSWORLD COM NOVEMBER 2018 WITH RICHARD B LANGLEY T he overreliance on GNSS is well known and widely publicized While GNSS is generally available concerns remain on how maritime operations and safe navigation in particular are affected should GNSS not be usable or become denied for any reason The General Lighthouse Authorities of the United Kingdom and Ireland GLA have been working on resilient positioning navigation and timing PNT for many years This work has included a comprehensive review of different potential solutions and their availability One option proposed is the development of a ship based positioning system that makes use of a modernized pelorus to work with a modern bridge Pelorus systems work by providing bearings from fixed positions normally on the vessel bridge wings to specific targets visible to the mariner and identified on the navigation chart By taking several bearings in quick succession intersecting lines can be drawn on the navigation chart providing a position estimation Clearly there are limitations to this approach these are explored within this article but can be summarized as Automation The time taken to measure the bearings can limit the achieved accuracy Visibility Performance is limited by the mariners ability to see unique targets Paperless bridges Many vessel bridges are moving away from paper limiting the mariners ability to take bearings and plot them e Navigation More bridge systems require electronic values of latitude and longitude In an attempt to resolve most of these limitations the GLA has been working on the development of an enhanced pelorus or ePelorus with its name registered to the Research and Radionavigation Directorate R RNAV as BinoNav Prototype BinoNav systems have been developed and installed on all GLA vessels for trial They enable the navigator to take visual bearings to known targets from anywhere on the bridge using a handheld device they are no longer confined to the bridge wings and targeting port or starboard objects Measured bearings are automatically registered and drawn on an electronic chart Multiple bearings can then be made with ease each of which is displayed on the chart and the intersecting cocked hat position to be discussed later calculated automatically This information can then be used to feed other bridge systems and confirm the vessels position In this article I will provide a comprehensive overview of the BinoNav system provide the results of initial trials and explain the planned development of the proposed resilient PNT solution E NAVIGATION Much has been written about e Navigation elsewhere but briefly it is the International Maritime Organizations IMOs concept for GPS Use on ship GPS DGPS positioning ECDIS AIS Gyro Radar Digital selective calling Vessel data recorder Dynamic positioning Surveying Satellite broadband antenna Satellite entertainment antenna Heli deck stabilization Ships clocks the future of navigation instigated by the U K Department for Transport in 2004 It will lead to the integration of systems and data for the exchange of relevant geolocated information faster and more cost effectively and it will do this in the context of larger faster vessels operating in ever more constricting shipping lanes and increasing offshore obstacles such as renewable energy infrastructure as well as the legacy of non renewable energy infrastructure e Navigation is designed to enhance safety of life for the mariner improve protection of the environment and increase energy efficiency in terms of shorter routing for fuel efficient BY Martin Bransby All images are credited to the author unless otherwise stated FIGURE 1 Ships systems affected by GPS jamming