Large ships, towing vessels and ferries are required to use the VTS, Gill said. They must report by radio at 13 checkpoints through the channels from Galveston to Houston. VTS controllers return information about traffic, weather advisories and dangerous conditions. In addition to the radio contact, controllers also keep tabs on traffic via radar in lower Galveston Bay. But for about 35 miles, the channel is too narrow and twisting for effective radar coverage.
Video picks up where the radar leaves off.
There are 11 video sites along the channel with two cameras at each site, one facing upbound and one downbound. Until June, live analog video signals arrived at the VTS Center over microwave, which was expensive to maintain and unreliable in bad weather. Calif. The signals go over a T1 Ethernet link to the VTS Center, where another Cisco router distributes them to five LiveSystem decoders. Controllers view the images on 15-inch monitors at PCs running Optivision's LiveWare client software. The center records video and radar data on a Hewlett-Packard AutoRAID disk array and periodically dumps data to tape for storage.