Live video transmitted during VISIONS ’14 brings fabulous imagery of exotic life forms at Axial Seamount and Hydrate Ridge to the screens of website viewers around the world. Scientists on shore use the live video and voice-over-IP telephones to consult with shipboard colleagues on the best placement of observatory instruments. Daily updates by Chief Scientist John Delaney and colleagues keep the ocean science community and other interested viewers informed about expedition progress. Participating students make short presentations about their at-sea research projects.
Those live video and audio streams have traveled tens of thousands of miles to reach monitors, tablets, and telephones on desks and in hands on land. The transport often begins with the signal from the HD video camera on the ROV ROPOS, which may be working as deep as 9,000 feet beneath the surface of the ocean. From there, the video travels up the fiber-optic cable that is part of the ROPOS umbilical cord and reaches the R/V Thompson. (Another HD video camera, deployed in the caldera of Axial Seamount, has occasionally transmitted live video during testing using ROPOS; when the regional cabled observatory is fully operational, this camera will stream live video via the primary cable and onto the Internet.)
Onboard ship, VISIONS ‘14 video manager, Ed McNichol, manages the feed from ROPOS as well as feeds from cameras set up several places on the ship. McNichol chooses which video to send to the onboard Streambox Encoder. From there a 3 Mbps encoded signal travels some 22,000 miles to the Intelsat Galaxy 18 satellite in a geostationary orbit and then down to a receiving antenna managed by UWTV that sits on top of Kane Hall on the UW Seattle Campus.
A Streambox Decoder in the UW School of Oceanography turns the signal from the satellite back into analog video that is then re-encoded by a Haivision Makito X encoder, which in turn creates four different output streams: 3 Mbps / 1 Mbps / 500 kbps /128 kbps. A Wowza server takes those streams and distributes them concurrently. The 1 Mbps stream is what viewers see integrated into the expedition website. The small 128 Kbps stream goes back to the ship for website monitoring and updating.
There are times when the video signal coming off the ship may be degraded: the ship may be on an unfavorable heading, weather conditions may not be favorable to transmission, or the ship is at the edge of the footprint serviced by this particular satellite. What viewers see on their screen may become smeared and blurry. Then it’s time to boost the signal coming off the ship until the vessel returns to a more favorable heading or the weather improves.