Networked Transport of RTCM via Internet Protocol (Ntrip) … IP-Streaming for Real-Time GNSS Applications

In September 2004 the Radio Technical Commission for Maritime services Special Committee 104 (RTCM SC- 104) completed a new standard which defines a protocol for streaming GNSS data to stationary or mobile users over the Internet. Titled “Networked Transport of RTCM via Internet Protocol (Ntrip)” the standard is named for the widely used RTCM data format, but it can also be used for streaming other kinds of data. The development of Ntrip was initiated by the German Federal Agency for Cartography and Geodesy (Bundesamt fur Kartographie und Geodasie, BKG) within the framework of the EUREF-IP Pilot Project [1]. Although there are uses for stationary DGNSS receivers that could access the Internet via landline, the growing availability of Internet service through the mobile telephone network was a persuasive reason to develop and formalize a publicly available Internet protocol for streaming DGNSS data. Ntrip is designed to distribute GNSS streaming data to stationary or mobile users over the Internet, allowing simultaneous PC, Laptop, PDA, or receiver connections to a broadcasting host. Ntrip supports wireless Internet access through Mobile IP Networks like GSM, GPRS, EDGE, or UMTS. RTCM’s new Ntrip standard already proved to be useful in support of positioning and navigation applications worldwide. Future applications may comprise satellite orbit and clock estimation, satellite health monitoring, global or regional estimation of ionosphere parameters or local streaming of troposphere parameters for Networked DGNSS/RTK services. The paper draws attention to IP- streaming for GNSS applications via Ntrip and its potential for science and research as well as public and commercial services in many areas.