Expedition Menu
1. Welcome
2. The Idea
3. Boarding
4. Ship Tour
5. Back Deck
6. Preparing to Depart
7. Leaving
8. Meeting
9. Bay-Delta-Estuary
10. Navigating
11. The Survey
12. First Data
13. The Mosaic
14. Visualizing
15. Hazards
16. Disposal Site
17. Sediment Map
18. Compare
19. Future Studies
20. Final Meeting
Contact
Don Reed
Dept. of Geology
San José State
University
Remember from our earlier discussion, multibeam sonar uses multiple beams of sound to produce an image along a swath of the seafloor extending outward from each side of the ship. It is a little bit like mowing the lawn, by going back and forth, ultimately an entire map will be produced from the individual swaths.
Remember that we will first measure the time for the sonar energy to travel from the bottom of the ship down to the bay floor and back to the ship. We will then convert this time to a distance, and hence the water depth (more on this in the next expedition).
Here is our first swatch of multibeam data along the bay floor. Honestly, one swath alone does not provide much information, but you get the general idea.
Let's
continue to build our seafloor image.