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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Data discovery tools

In order to facilitate easy access to CDDIS data and information, several tools are under development. At this time, the following tools are available:

CDDIS archive explorer logo

CDDIS Archive Explorer

Search the CDDIS data archive for SLR, DORIS, or GNSS data.

site log viewer logo

Site Log Viewer

Browse SLR, DORIS, or GNSS site logs by individual site or across multiple sites. The tool will be expanded soon to include VLBI site logs.

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Site Selection Tool

Search and discover CDDIS data holdings using the GSAC-WS.