Fig. 1. Post-processed multibeam bathymetry Click for hi-res (0.6M) image   Fig. 2. Post processed side scan data Click for hi-res (1.9M) image Fig. 3. Post processed sub-bottom data Click for hi-res (0.4M) image

Post-processed AUV data

During each mission, subsampled data is transmitted to the support vessel in real time. The AUV is retrieved at two-day intervals and the raw data is downloaded over a 100-baseT Ethernet.

The full data sets are used to produce finished survey charts and reports. A high-speed INMARSAT terminal is used to transmit finished products to C & C's office, where they are placed on a secure Web site for clients' immediate access.

Figure 1 depicts the Sigsbee Escarpment in the Gulf of Mexico with depths ranging from approximately 1,100-2,200 meters.

The depth resolution achieved by the C-Surveyor™ I AUV was on the order of 20 cm (8 in), or 0.02 percent of the water depth. These post-processed multibeam bathymetry data are color-coded at one-meter contour intervals.

Figure 2 provides an example of mega-furrows and a seafloor slump deposit at the base of the Sigsbee Escarpment. The mega-furrows are five to 50 meters in width and one to three meters in depth. These erosional features extend for kilometers and are the result of bottom currents. The slump deposits are more resistant to the erosional process.

The subbottom profiler data shown in figure 3 is processed and saved in SEG Y and XTF. A subbottom profile, running from north to south across the slump deposits noted in the figure 2, shows furrowed seafloor in the form of hyperbolic echoes.