Once registered, please check the current stream table at http://www.igs.org/rts/products and select the stream appropriate for your application. Each stream is described by the set of features, among which the most important are:
List of GNSS systems that are supported by a stream. Currently you may select only GPS (GPS) or GPS and GLONASS (GPS+GLO) satellites supporting streams.
The information about the reference is included in the stream identifier. They should be applied for broadcast orbits (BRDC). The resulting orbits are in current ITRF (ITRF) system. After applying the corrections, coordinates may be referred to satellite center of mass (CoM) or antenna phase center (APC). In the first case, the antenna phase center offset of each satellite is removed. APCs are directly prepared for positioning applications, unless You want to apply offsets on your own to CoM. For other specific applications, you should select the reference type according to your requirements.
Message types and intervals
Each stream provides different set of State Space Representation (SSR) messages and with different interval. The message type is identified by a four-digit number (see the Knowledge Base article "IGS Real Time Pilot Project (RTPP) Product Formats"). The message transmission rate is provided in parentheses after the identifier and may not be compatible with message update interval.
Among many available strings, some may transmit GNSS broadcast data, in case you can’t or don’t want to download broadcast ephemeris from Your receiver. Navigation data is disseminated using 1019 (for GPS) and 1020 (for GLONASS) message type. Coordinates and clocks are by default referred to APC.