|Benoit-Bird, Kelly||Oregon State University (OSU-CEOAS)||Principal Investigator|
|Waluk, Chad||Oregon State University (OSU-CEOAS)||Contact|
|Rauch, Shannon||Woods Hole Oceanographic Institution (WHOI BCO-DMO)||BCO-DMO Data Manager|
Integrated, area scattering values, or Natuical Area Scattering Coefficients (NASC) are provided from one cruise in the Guaymas Basin that occurred October 2013. Also included are the time (UTC) and location at the start and end of each integration bin, mean depth of the exclusion line for each bin, and the average thickness of the integrated cell.
Note that noise removal from this data set (e.g. splash down, electrical interference, and CTD casts) was minimal before integration. Raw acoustic scattering data (.raw files) are extremely large. These are archived at Oregon State University and will be shared using physical media upon request.
See Benoit-Bird & Gilly (2012) and Hoving et al. (2013).
Acoustic data were collected nearly continuously using Simrad EK60s at 4 frequencies (38, 70, 120, and 200 kHz). Split beam transducers (Simrad model numbers: 38-12, 70-7c, 120-7c, 200-7c) were mounted 1.5 m below the surface on a rigid pole. Each transmitted a 512 us pulse as frequently as possible for the water depth. Raw data were stored using Simrad ER60 software.
Acoustic backscattering values at 38 kHz that were greater than -75 dB were integrated in 1 km horizontal bins from depths of 5m to 500m or 1 m above the bottom, whichever was shallower. These integrated, area scattering values or Nautical Area Scattering Coefficients (NASC: m2 nmi-2) are provided. Noise removal from this data set (e.g. splash down, electrical interference, and CTD casts) was minimal before integration.
BCO-DMO Processing Notes:
- Modified parameter names to conform with BCO-DMO naming conventions.
- Reformatted display of time from HH:MM:SS to HHMM.mmmm
|date_start||Date at start of integration bin.||YYYYmmdd|
|time_start||Time (UTC) at start of integration bin in hours, minutes, and decimal minutes.||HHMM.mmmm|
|date_end||Date at end of integration bin.||YYYYmmdd|
|time_end||Time (UTC) at end of integration bin in hours, minutes, and decimal minutes.||HHMM.mmmm|
|NASC||Nautical Area Scattering Coefficient (NASC).||m2 nmi-2|
|lat_start||Latitude at start of integration bin.||decimal degrees|
|lon_start||Longitude at start of integration bin.||decimal degrees|
|lat_end||Latitude at end of integration bin.||decimal degrees|
|lon_end||Longitude at end of integration bin.||decimal degrees|
|exclusion_line_mean_depth||Mean depth of the exclusion line for each bin.||meters|
|integration_layer_thickness_mean||Average thickness of the integrated cell.||meters|
|Dataset-specific Instrument Name|| |
Simrad EK-60 echosounder
|Generic Instrument Name|| |
Simrad EK-60 echosounder
|Dataset-specific Description|| |
Acoustic data were collected nearly continuously using Simrad EK60s at 4 frequencies (38, 70, 120, and 200 kHz). Split beam transducers (Simrad model numbers: 38-12, 70-7c, 120-7c, 200-7c) were mounted 1.5 m below the surface on a rigid pole.
|Generic Instrument Description|| |
A split-beam scientific echosounder primarily designed for fisheries research. It can operate seven frequencies simultaneously ranging from 18 to 710 kHz. Real time echo integration and target strength analysis in an unlimited number of layers is provided as well as storage of raw data for replay or analysis in one of several post-processing software packages such as Simrad's BI60.
R/V BIP XII
|Start Date|| |
|End Date|| |
Central Gulf of California, Mexico: Santa Rosalia (27.3N 112.1W) to Bahia Las Animas (28.9N 113.3W to Guaymas (27.8N 111.3W)
This document is created by info v 4.1f 5 Oct 2018 from the content of the BCO-DMO metadata database. 2020-02-24 14:57:25