Raw SeaWiFS telemetry is received by MBARI's antenna, decoded by the black box, backed up to tape, transformed into L0 files, and placed in directory seawifs/seawifs/l1agen/L0 on Lepas. At 3:15 pm each day, a script called /usr/people/seawifs/autoproc, processes the L0 data to L1A data using "batchL0". If the process is successfull, the L0 file will move to seawifs/seawifs/l1agen/L0_done and if not, it will move to seawifs/seawifs/l1agen/L0_failed. When the files apear in L0_done, an automatic e-mail is sent to NASA, and old data is removed from the disk. The e-mail triggers a NASA script that ftp's into Foam and picks up the new L1A file.
Further documentation of these scripts can be viewed by clicking here
Once the L1A data is at NASA, it is processed from L1A data into L2 data using the NASA algorithms. Once complete, NASA sends back an e-mail notifying the status of the processing.
Every night, a crontab file runs the script, "getL2" (Lepas:/seawifs/seawifs/data/L2/). This script retrieves any files from the NASA ftp site not found on the MBARI system. This has the advantage of ignoring days when there is no data, and recovering more than one days data should a system fail for a full day on either end.
The script getL2 also calls multiple SeaDAS and PERL scripts. These subsceen and map the data, and create gif's for the web site, and extract values for the pixels that surround the moorings. This script then calls a similar script called getSST (Lepas:/seawifs/seawifs/data/L2/) which ftp's to Oregon State for AVHRR the SST data, and cleans up the SST file structure.
Finally, as the disk on Lepas fills up with L2 data, the SeaWiFS images are moved to CD ROM and archived. This process needs to be done approximately once per month to maintain enough disk space for SeaDAS to operate. Each CD ROM can hold about 10 days worth of full L2 files, and each disk requires about thirty minutes to write, so plan on 2 hours of writing time per month. Instructions for writing CD's are found in the Care and feeding of the MBARI Satellite System.
For a more detailed data path including disks and machines, click on one of the links below: