Radio Technical Commission for Maritime Services The State and Status Special Committee – 104 20 March, 2014 NOAA March 2014 NOAA / NGS RTN Webinar Kendall Ferguson Hemisphere GNSS, Senior Principal Design Engineer RTCM, SC-104 Chair & Board of Directors Stafford, VA USA

Presentation Outline Question Often Asked Why is RTCM, an apparent maritime-based organization, involved in carrier-based real-time GNSS provider networks? Existing Standards: State and Work In Progress The current standards Work in progress New work on the horizon Summary

Two Main Message Standards RTCM 2.3 (RTCM 10402.3) Codephase Differential Corrections Primarily L1-Only, GPS-Only (though there is some support for GLONASS) For SOLAS applications Message format developed with primary communication link layer in mind MF/LF Band at 25-300 bps Typical Accuracies < 1 m Yes, RTCM 18-21 support carrier applications but these are not SOLAS RTCM 3.2 (RTCM 10403.2) Carrier and Code Differential Corrections for High-Precision For RTK, Network RTK, and PPP-type applications Recently modernized with, so called Multiple Signals Messages (MSM), for generic inclusion of new constellations and signals MSM Currently supports GPS, GLONASS, Galileo, QZSS, BeiDou, SBAS Though some work still in progress for newer constellations and signals Message structure designed with OSI 7-layer architecture in mind

Standards Work In Progress RTCM 10402.3 (i.e., Version 2.3)  Version 2.4 Multi-GNSS/Multi-Frequency (i.e., DGNSS). Via new generic messaging approaches (e.g., Type 41 and 42). Potential for 2 dm 2 σ (at max broadcast range). Supports Legacy Message Interleave (e.g., Type 1 and 9). Recommending Retirement of Types 18-21 RTCM 10401.2 (i.e., RSIM 1.2)  RSIM 1.3 Defining Reference Station (RS), Integrity Monitor (IM), Control Station (CS) and Transmitter (TR) Performance, Functions, and Messaging for SOLAS DGNSS Applications. Modernizing from L1 GPS only to Multi-GNSS/Multi-Frequency Adding further Alarm Attributes to Aid in Monitoring and Reporting of Alarm Conditions Reduce Load on Control Station Operators Speed System/Component Failure Detection and Recovery

Standards Work In Progress (continued) RTCM 3.2 Version 3.2 Published February 1, 2013 Mostly to collect the numerous revisions to Version 3.1 These 3.1 updates include: First Multiple Signals Messages (MSM) First State Space Representation (SSR) Messages MAC and FKP Messages Amendment 1 (Published July 12, 2013) Added BeiDou Multiple Signals Messages (MSM) Added Galileo F/Nav Ephemeris Message Amendment 2 (Published Nov 7, 2013) Added QZSS Multiple Signals Messages (MSM) Added QZSS Ephemeris Message

Standards Work In Progress (continued) RTCM 3.2 (Work In Progress) State Space Representation (SSR), a message for PPP-type uses Phase I: already in published 3.2 Phase II: adding additional models such as TEC (in progress) Phase III: carrier based clocks (in early development states) Coordinate Transformation Messages improvements underway Network RTK Approaches (i.e., Non-Physical Reference, MAC, and FKP) Currently GPS and GLONASS only Committee currently deliberating adding other constellations and signals Navigation Data Frame (NDF) messages under deliberation Carries raw navigation data frames from various satellites: GPS, GLONASS, BeiDou, QZSS, and SBAS.

Standards Work In Progress (continued) Network Transport of RTCM via Internet Protocol (Ntrip) Ntrip Version 2.0, with Amendment 1 Published on June 28, 2011 Widely used in industry carrying not only RTCM data but numerous other data (even beyond proprietary GNSS receiver data) Supporting TCP/IP, UDP, and SSL Work In Progress Sourcing the Station Log Files Offering suggested source table meta-names to aid in more automation of stream selections.

RINEX Working Group RINEX and SC-104 Tighter Relationship (~2 yrs ago) RINEX and RTCM essentially deal with same ‘observables’ The independent committees now jointly develop solutions Example: Phase alignment Ensure RINEX can be created from RTCM 3.x Joint decision to only further development of 3.x Example: RINEX 3.02 supports BeiDou; version 2.x does not. BKG developing open source for RTCM 3 and RINEX converters http://software.rtcm-ntrip.org/ teqc equivalent in the plans RINEX 3.03 current being considered Several issues with 3.02 raised by community that may require 3.03 Any version beyond 3.02 will likely undergo RTCM-type interoperability testing

NMEA Working Group NMEA and SC-104 Tighter Relationship RTCM SC-104 Standards messages traditionally from Reference Receiver / Network sent to User Community requesting standardized messages for high precision work carrying end solutions reaching a wider range of other applications, systems and devices Formed an NMEA Working Group (WG) within SC-104 Will be developing messages that essentially carry solution results to other applications, systems and devices Will likely be developing messages targeted at Network management side Receiver Controls: e.g., reset commands, elevation masks, etc. These will be developed under NMEA-0183, 2000, and the new OneNet WG Formed Sept 2013, thus no progress yet to report

Thank You Thank You RTCM SC-104 Participation Questions