US Government security requirements no longer permit CDDIS to offer data via traditional unencrypted anonumous ftp; this service was discontinued on October 31, 2020. All data are still available, however access must be via HTTPS or ftp-ssl.

Instructions with examples and our FAQ can be found at:

If you still have difficulty after reading and attempting the examples on that page, please contact us at

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Real-time data

The CDDIS has configured dedicated servers for receipt and transmission of real-time GNSS data and product streams in support of the IGS Real Time Service. The CDDIS has installed and tested the required real-time streaming software (NTRIP, Networked Transport of RTCM via Internet Protocol). The available product streams consist of GNSS orbit and clock corrections, which enable varied applications such as precise point positioning (PPP). In the near term, the CDDIS plans to continue testing and coordination with the RTS. Future plans include capturing incoming data streams for generation of high-rate data files from real-time stations.

More information and registration details on the real-time GNSS streams available from the CDDIS can be viewed on the CDDIS Caster Description webpage.