NDADS File Transfer Hints

Anonymous FTP may be used to copy your data from NDADS to your computer. Please be sure to use binary mode. Here's a sample session:

        ftp ndads.gsfc.nasa.gov
        user anonymous
        (enter your email address as the password)
        cd data_dist.iue
        binary
        ls LWP12345.*
        get LWP12345.MXLO
        ls SWP09876.*
        mget SWP09876.*
        exit

In addition, VMS users can use the VMS remote COPY command as an alternative to FTP. In this case, to copy the same files as shown above enter the following:

        COPY NDADS::ANON_DIR:[DATA_DIST.IUE]LWP12345.MXLO  *.*
        COPY NDADS::ANON_DIR:[DATA_DIST.IUE]SWP09876.*   *.*

Potential IUE File Transfer Problems

IUE archive data requested from NDADS are staged on a VAX computer at NSSDC. To support FTP file transfers, the VAX computer uses Multinet tcp/ip support software. Although this is transparent to most requesters, in some circumstances users may encounter formatting problems when transferring data from NDADS to their home computer.

FTPing RDAF-format IUESIPS files to Unix computers

Archived IUESIPS files are available in RDAF-format, GO-format, or GO-split format. The RDAF-format files use the VAX VMS floating point data format and must be converted to IEEE format to be properly interpreted on unix computers. The IUEDAC program con_rdaf was written for this purpose. This problem does not occur with the GO and GO-split file formats.

FTPing GO-format IUESIPS files to VAX computers

GO-format IUESIPS files are stored as variable-length record files at NSSDC. This format is preserved when transferred to a VAX computer using a remote DECnet COPY command and when Multinet FTP is used. If the file is transferred to a VAX computer with another version of FTP, the file structure may not be preserved and the software to read the file may not work. It is believed this problem does not occur with the fixed-length record RDAF and GO-split file formats.

FTPing NEWSIPS files to VAX computers

NEWSIPS FITS files FTPed to a VAX computer using a version of FTP other than Multinet may result in files containing 512-byte records rather than the standard 2880-byte records. The same result occurs when FITS file are transferred from unix to VMS computers. In either case, problems can occur if the FITS reader was written to read physical records rather than logical records.

If you have problems copying files to your computer or reading the data, please contact the ST Archive help desk.