GNSS Center Software developed by Leoš Mervart is a framework for several plugins. Currently the following plugins have been published under GNU license:
- BKG Ntrip Client (BNC)
- RTNet Monitor
- Input Editor
BKG Ntrip Client
The BKG Ntrip Client (BNC) is a program for simultaneously retrieving, decoding, converting and processing real-time GNSS data streams. It has been developed within the framework of the IAG sub-commission for Europe (EUREF) and the International GNSS Service (IGS). Although meant as a real-time tool, it comes with some Post Processing functionality. BNC has been written under GNU General Public License (GPL). Source code is available from Subversion software archive http://software.rtcm-ntrip.org/svn/trunk/BNC Binaries for BNC are available for Windows, Linux, and Mac OS X systems.
The BKG Ntrip Client (BNC) and its Qt graphic user interface has been developed for Federal Agency for Cartography and Geodesy (BKG), Department of Geodesy by Leoš Mervart. BNC includes the following GNU GPL software components:
- RTCM 2 decoder, written by Oliver Montenbruck, German Space Operations Center, DLR, Oberpfaffenhofen, Germany;
- RTCM 3 decoder for conventional and MSM observation messages and a RTCM 3 encoder & decoder for SSR messages, both written for BKG by Dirk Stoecker, Alberding GmbH, Schoenefeld, Germany.
The purpose of BNC is to
- Retrieve real-time GNSS data streams available through NTRIP transport protocol;
- Retrieve real-time GNSS data streams via TCP directly from an IP address without using the NTRIP transport protocol;
- Retrieve real-time GNSS data streams from a local UDP or serial port without using the NTRIP transport protocol;
- Generate RINEX Observation and Navigation files to support near real-time GNSS Post Processing applications;
- Generate ephemeris and synchronized or unsynchronized observations epoch by epoch through an IP port to support real-time GNSS network engines;
- Generate orbit and clock corrections to Broadcast Ephemeris through an IP port to support real-time Precise Point Positioning on GNSS rovers;
- Generate synchronized or unsynchronized orbit and clock corrections to Broadcast Ephemeris epoch by epoch through an IP port to support the (outside) combination of such streams as coming simultaneously from various correction providers;
- Monitor the performance of a network of real-time GNSS data streams to generate advisory notes in case of outages or corrupted streams;
- Scan RTCM streams for incoming antenna information as well as observation types and message types and their repetition rates;
- Feed a stream into a GNSS receiver via serial communication link;
- Carry out real-time Precise Point Positioning to determine a GNSS rover position;
- Simultaneously process several Broadcast Correction streams to produce, encode and upload combined Broadcast Corrections;
- Upload a Broadcast Ephemeris stream in RTCM Version 3 format;
- Read GNSS orbits and clocks in a plain ASCII format from an IP port. They can be produced by a real-time GNSS engine such as RTNet and should be referenced to the IGS Earth-Centered-Earth-Fixed (ECEF) reference system. BNC will then
- Convert the IGS Earth-Centered-Earth-Fixed orbits and clocks into Broadcast Corrections with radial, along-track and cross-track components;
- Upload Broadcast Corrections as an RTCM Version 3 stream to an NTRIP Broadcaster;
- Refer the orbit and clock corrections to a specific reference system;
- Log the Broadcast Corrections as Clock RINEX files for further processing using other tools than BNC;
- Log the Broadcast Corrections as SP3 files for further processing using other tools than BNC;
- Edit or concatenate RINEX files or check their quality;
- Plot stream distribution map from NTRIP Broadcaster source-tables;
- Plot positions derived from RTCM streams or RINEX files on maps from Google Map or Open StreetMap.
The following figures show the various applications of the BNC:
RTNet Monitor
RTNet Monitor is a program for the visualization of the GNSS data processing. The program uses the thrift technology (see thrift.apache.org) for the communication with the processing software (e.g. Real-Time Network Software, GPS Solutions, Inc.) and is capable of displaying current processing status in real time. The following figure shows the plots with number of stations and satellites being processed:
