US Government security requirements no longer permit CDDIS to offer data via traditional unencrypted anonymous 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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On-board receiver data

The CDDIS began archiving data from flight receivers on board LEO satellites in support of the IGS LEO Working Group. Satellite data available in this archive include CHAMP, ICESat-1, Jason-1, and SAC-C. All flight receiver data are stored in RINEX format.

The starting directory for these files is:

Append the following directory and file names to the starting directory:


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Satellite Name

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Satellite NameCode

as described in the table below.

Code Meaning
SATNAME satellite name
YYYY4-digit year
DDD3-digit day of year
SSSSsatellite code
YY2-digit year
ttype of data:

d = Hatanaka-compressed observation data
s = observation summary files (output of TEQC)
o = ICESat GPS data in standard RINEX format
pc = ICESat position solution from receiver
.Z UNIX compressed file