[IGSMAIL-4376]: REAL-TIME GNSS - Data Availability and Call for Participation
georg.weber at bkg.bund.de
georg.weber at bkg.bund.de
Tue May 13 02:49:12 PDT 2003
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IGS Electronic Mail 13 May 02:49:36 PDT 2003 Message Number 4376
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Author: Georg Weber & Carine Bruyninx
Dear Colleagues,
With the increased capacity of the Internet, applications that transfer
continuous data streams by IP-packages, such as Internet Radio, have become
well-established services. Compared to these applications, the bandwidth
required for a real-time transmission of GNSS data is relatively small.
Following previous activities (see IGSMAIL-3977), EUREF consequently decided
in June 2002 to set up and maintain a real-time GNSS infrastructure on the
Internet using a sub-set of stations of its European GPS/GLONASS Permanent
Network EPN. Although today's primary objective is to disseminate RTCM
corrections over the Internet for precise differential positioning and
navigation purposes, various other applications are in sight. According to
efforts as coordinated within the IGS Real-Time Working Group, weather
prediction, ionospheric weather monitoring, earthquake and volcano
monitoring, positioning of structures, timing and earth orientation may
benefit from the availability of real-time GNSS raw data and from real-time
or near real-time products computed from them.
In view of the overall trend towards real-time, you are herewith invited to
participate in the EUREF-IP pilot project and take the opportunity to
retrieve real-time GNSS data from the Internet. Those who have some
responsibility over continuously operated GNSS reference stations are
requested to consider a station upgrade to real-time provider capability
and/or to host a Broadcaster on the Internet. Detailed information on this
Call for Participation can be downloaded from
http://www.epncb.oma.be/projects/euref_IP/euref_IP.html.
ACCESSING REAL-TIME GNSS DATA
GNSS data streams are available through EUREF's Internet Broadcaster. This
includes currently about 25 raw data streams, 20 RTK data streams, 25 DGPS
data streams, and 15 DGPS Virtual Reference Station (VRS) data steams from
various networks in Europe and the US. 12 Stations provide GPS and GLONASS
data. The Broadcaster's Internet connection handles a maximum of 1000 users
simultaneously. Some of the data streams are available for demonstration
purposes and thus are accessible without authentication/authorization. For
receiving protected data streams, the user needs a user-ID and a client
password. Please use the EUREF-IP user registration form for requesting
access. This form is available through
http://www.epncb.oma.be/projects/euref_IP/euref_IP.html.
For receiving the real-time data you may use the GNSS Internet Radio
available for MS Windows operating systems. This client program is designed
to run on a PC or Laptop. It handles all communication through HTTP and
transfers the received GNSS data to a serial or IP port supporting your
networking software or DGPS/RTK application.
CALL FOR PARTICIPATION: Providing Real-Time Data
The EUREF-IP current test network needs densification. Support is welcome
from geodetic GNSS receivers continuously operated close to an Internet
connection. During this pilot project, the following stations are accepted:
- EPN stations part of the EUREF Permanent Network.
- Non-EPN stations that are not yet included in the EPN,
but are expected to join the EPN.
- Stations outside Europe which would like to participate
in view of upcoming IGS real-time activities.
Any provider must guarantee up to 10 kbits/sec Internet bandwidth per stream
in order to allow a continuous uninterrupted service. Feel free to download
the necessary server software for Windows OS reading from a serial or IP
Port. To become a stream provider, it is necessary to register through the
EUREF-IP provider registration form available through
http://www.epncb.oma.be/projects/euref_IP/euref_IP.html.
CALL FOR PARTICIPATION: Hosting a Broadcaster
The software for broadcasting GNSS data in real-time is written for Linux
Operating Systems and will become available under GNU General Public License
by mid of 2003. It allows a massive simultaneous user access. EUREF-IP is
seeking for a limited number of institutions/agencies interested in hosting
a Broadcaster. The aim is to set up a small well-distributed network
satisfying real-time GNSS requirements in various regions. Please feel free
to mail to euref-ip at bkg.bund.de for further information on the planned
Broadcaster network and announce your interest.
NTRIP: The Communication Technique
The real-time GNSS data dissemination technique developed within the
framework of EUREF is called 'Networked Transport of RTCM via Internet
Protocol' (Ntrip). Ntrip stands for an HTTP application-level protocol
streaming GNSS data over the Internet. It is designed for transmitting
differential correction data (e.g in the RTCM-104 format) or other kinds of
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. Detailed information is available
from http://igs.ifag.de/index_ntrip.htm.
Georg Weber
EUREF-IP Pilot Project, BKG, Frankfurt
Carine Bruyninx
EPN Central Bureau, ROB, Brussels
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