Presentation on theme: "Implementing the Multi- Source Positioning Service: The Multi-Source Receiver Dr. Paul Williams General Lighthouse Authorities United Kingdom and Ireland."— Presentation transcript:
Implementing the Multi- Source Positioning Service: The Multi-Source Receiver Dr. Paul Williams General Lighthouse Authorities United Kingdom and Ireland ACCSEAS Conference Rotterdam 16 th - 19 th February 2015
ACCSEAS Resilient PNT: Two Important and Novel Results! ACCSEAS receiver -We’ve built the world’s first prototype Multi-Source Resilient PNT Receiver! -Based on GNSS as primary PNT source, integrity algorithms and a terrestrial (frequency and system diverse) backup R-Mode -Investigated a way of adding ranging signals to already existing IALA DGPS radio-beacons and AIS VHF base-station transmissions -Michael Hoppe – WSV – Feasibility Study and Trial
Ship-side Resilient PNT With Data Processing Element
terrestrial Resilient PNT Options Harden existing systems – Adaptive antennas – Plausibility checks Inertial Navigation Systems Use dissimilar services – Radar Absolute positioning – Ranging mode (R-mode) – eLoran Only need one fully working system to demonstrate the principles Resilient PNT receiver/engin e terrestrial Other PNT source Resilient PNT solution GNSS
RADAR Absolute Positioning: Results of Static Tests Derive Latitude and Longitude from one or more RADAR returns Single racon accuracy 40 m within 5 M, 100 m at 12 M With two racons, 2 m accuracy achieved Availability of single racon fix at under 5 M was 98% Availability of two-racon fix dictated by more distant racon at 87%
R-Mode Feasibility Study Add a ranging signal to the broadcast of IALA DGPS radio- beacons Also AIS base stations Feasibility study and experimental transmissions performed More detail in the presentation from Michael, coming next
eLoran in the NSR Runs continuously; available since May 2010; 10-20m accuracy in ports with differential service (green area)
Resilient PNT Data Processor Computes a position solution based on TOA measurements from eLoran receivers, as required (also RMode as a future expansion) Stores and applies propagation data corrections (e.g. eLoran ASFs) Applies differential correction data to the pseudorange measurements of terrestrial PNT services Computes and maintains the Horizontal Protection Levels (HPL) for complementary PNT services and the primary DGPS service – independent performance monitoring Detects incidents of GPS interference and jamming, and monitors the interference level Automatically and seamlessly switches the main PNT output of the service to the best available backup source given the prevailing interference/jamming/outage conditions Generates alarms for the purposes of notifying the mariner and shore-based stakeholders
Use of GPS in the Maritime Sector GPS has become the normal means for maritime positioning, navigation and timing. The level of integration onboard is different for each vessel depending on equipment fitted. But GPS is everywhere!
Receiver Standards IMO: NCSR Developing Multi-Source Receiver Performance Standard Not stipulating what systems to use, but calls for system diversity in terms of frequency, systems and resilience. Hope to be completed by March 2015, whereupon final draft will be sent to MSC later in the year IEC Receiver test standards Generally waits for IMO approval and works to their standards, but can start earlier RTCM SC-131 is drafting test specification IEC will likely take 2 years to complete specification RTCM Starting point for technical specifications SC-131 – MSRX, SC-127 – eLoran, SC-104 – DGPS (MF R-Mode) Likely not going to be mandatory carriage requirements, but ship owners will upgrade as part of their normal equipment replacement schedules.
Thank You! Dr. Paul Williams email@example.com The General Lighthouse Authorities Trinity House The Quay Harwich Essex CO12 3JW United Kingdom http://www.gla-rrnav.org Tel: +44-1255-245146 firstname.lastname@example.org