Sidescan sonar and navigation field data collected during R/V Caleta 91-1 cruise (10-14 June, 1991)

Description of the cruise from the cruise report contained in the Open-File Report:
This cruise was the shakedown cruise for Rutgers University's new coastal research vessel. The CALETA is a 30 ft vessel with an inboard/outboard drive and a small pilot house and space for two bunks in the forepeak of the boat. She did not have enough electric power for our gear, so we brought our own generator which had to be set up on the fantail. Lab space was very confined, but we managed to get everything aboard and operational. Weather was a more serious problem. When seas reached about 3 feet, the data quality was degraded enough to require retreiving the gear and waiting for improved weather. One day was a complete loss due to weather, and during the other 4 days we surveyed for a total of about 15 hours, and collected about 115 km of trackline data.
The objectives of surveying the surficial geology and shallow subsurface stratigrapphy of this inner shelf sand ridge were successfully achieved although we were unable to survey a second sand ridge as we originally had hoped because of the time lost to weather.
The sidescan sonar images revealed two basic facies in the study area. Much of the area was covered by a low-backscatter facies, but high-backscatter bands and patches were found on the seaward side of the sand ridge, in the trough on the seaward side of the sand ridge and around its northern end, and on the face of the slope shoreward of the sand ridge. The high-backscatter bands were discontinuous, and in places appeared to cross eachother giving the appearance of a braided stream. Ripples were not apparent in the high backscatter bands, and if they were present they either had been smoothed over by biological activity or were too small to be resolved by the sidescan sonar system. The high backscatter areas had no apparent relief with the surrounding sea floor as has typically been seen in other places. The apparent absence of ripples and the lack of relief along the edges of these bands may indicate that they were relatively old.
The 3.5-kHz subbottom profiles showed a southeasterly trending buried channel below the study area, and three distinctive shallow subsurface acoustic facies in the study area. The sand ridge itself was covered by an acoustically transparent lens that reached as much as 3 m in thickness, and pinched out along its edges. The upper 5-6 m of the subbottom section of the northeastern half of the study area away from the sand ridge was characterized by an acoustically laminated facies. The southeastern half of the study area was characterized by a prolonged acoustic return. The distribution of these echo character patterns did not correspond with the patterns seen on the sidescan sonar images, but instead appear to record a longer period of stratigraphic differences in the evolution of this section of the inner shelf.

Information from the readme.txt file contained in the Open-File Report:
Along track bathymetry collected during the cruise: The data were collected using an Odem 200kHz fathometer and were logged every 10 seconds with the navigation on 3.5" diskettes. The bathymetry data has been adjusted to mean sea-level based on tide information from Atlantic City, NJ. ***although the report indicates tide corrections, it doesn't indicate the tidal datum the bathymetry was corrected to.
Collected sidescan sonar data: These data were collected using a Klein 100-kHz sidescan sonar system and were logged on a Triton Technologies, Inc., QMIPS-DSP system. The sidescan sonar data were collected at a resolution of 100 m per side. The sidescan sonar data are 8-bit binary, and the format is summarized in the writeup in a text file located in the DOC directory. The data description is also available in HTML format. The archived sidescan sonar data are split and stored on two separate disks.
Ship navigation collected during the sidescan sonar componenet of the field program: USGS differential GPS system. The shorebased station for the GPS was the Coast Guard beacon at Cape Henlopen, DE. Navigation fixes are at 1 minute intervals. There are four individual files. These files correspond only to the days that the sidescan sonar data were collected during the survey.

The original report did not contain a metadata file. This file was created based on information in the report.