Real-time Data Telemetry - Background

It is anticipated that the vessels will be linked to shore automatically once per hour for one to ten minutes per transmission. The frequent updating of information is an essential objective of this service. The down-link will be via UNIX or NT (to avoid difficulties resolving 16-and 32-bit MSDOS microprocessor incompatibility).

Assumptions

1. Data collected automatically via ship's instruments are "packaged" with metadata (e.g. date, time, position) aboard ship and held for one hour, or until next transmission.
2. These packaged data are transfered to the telemetry system for telemetry ashore as email messages. [Hartley left me a a magazine called Ocean Voice, October 1996, which on pages 7-9 talks about sending and receiving email via Inmarsat-C.] It is important that these telemetry sessions occur automatically, without the need for human interaction. Doing this within a unix envirnonment would be easy; I don't know offhand, how I would schedule a recurrent task within a PC/Windows environment, but believe it can be done.
3. The receiving system (call it lena.whoi.edu) is a unix based machine located at WHOI that will have three functions:
   • Web (data) server - to serve the collected data and information. This is just like the U.S. GLOBEC Georges Bank server but dedicated, and separate from, GLOBEC data. It will use standard Web serving software (e.g. Apache's httpd server) and the JGOFS data management system software. We can tie globec and NOPP data together if this is necessary, however.
   • Data receiver - telemetered data will be received by lena.whoi.edu as email messages (or perhaps ftp files), parsed into appropriate data files and automatically made available via the JGOFS software as appropriate.
   • Data repository - data received and "processed" will be stored on lena.whoi.edu for serving via the Web using the JGOFS software (see above). This does not preclude other sites from being data servers, however, as the JGOFS system supports distributed data servers.

Open Issues

1. Will the Fish Exchanges be JGOFS data servers and if so will they be able to connect to a phone line 24 hours per day? This seems unlikely so we will have to investigate whether an ISP (Internet Service Provider) will be willing to install the necessary JGOFS software to enable serving. This is possible, but I suspect the ISP will charge more than the standard $20 per month charge.
2. Data will need to receive quality control and in some cases post-acquisison processing. We need to identify the resources to accomplish these tasks.
3. We need to select a data transmission "vendor" based on cost and throughput capabalities. The vendor must provide global coverage.