Dataset: acoustic backscatter120 kHz
Deployment: NBP0104

120 kHz acoustic backscatter relative decibels

Principal Investigator:

Peter H. Wiebe (Woods Hole Oceanographic Institution, WHOI)

BCO-DMO Data Manager:

Ms Dicky Allison (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

GLOBEC: Winter Distribution and Success of Southern Ocean Krill (Southern Ocean Krill)

U.S. GLOBEC Southern Ocean (SOGLOBEC)

Deployment Synonyms:

GLOBECII

Coordinated Deployments:

LMG0106

Data URL:

https://www.bco-dmo.org/dataset-deployment/450369/data

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Description

These relative decibel values are the result of processing the NBP0104 and NBP0103 volume backscatter data from BIOMAPER-II at 120KHz. They are relative decibel values derived from the backscatter data (in volts) and normalized according to the algorithms in the Matlab routine docurtainnf.m. The algorithm includes the following steps:

Add 10^-10 to each value
Multiply result by by 10¹⁰ to get values with units of m²/m³ (called sv)
Take the log (called SV)

These are energy backscattering values.

The values are presented as twenty groups of 20 numbers in each group. Each number is displayed as NNN, where there is an assumed decimal point at NN.N and all values should be negated. That is NNN, is really -NN.N.

See the related objects sv120coords_0104 and sv120depths_0104 for NBP0104 and sv120amcoords_0103, sv120pmcoords_0103 and sv120depths_0103 for NBP0103.

Methods & Sampling

Dataset acquisition description

Add 10^-10 to each value
Multiply result by by 10¹⁰ to get values with units of m²/m³ (called sv)
Take the log (called SV)

These are energy backscattering values.

Deployment-specific acquisition description

These relative decibel values are the result of processing the NBP0104
and NBP0103
volume backscatter data from BIOMAPER-II at 120KHz. They are relative decibel
values derived from
the backscatter data (in volts) and normalized according to the algorithms
in the Matlab routine docurtainnf.m. The algorithm includes the following
steps:

Add 10^-10 to each value
Multiply result by by 10¹⁰ to get
values with units of m²/m³
(called sv)
Take the log (called SV)

These are energy backscattering values.

The values are presented as twenty groups of 20 numbers in each group.
Each number is displayed as NNN, where there is an assumed decimal point
at NN.N and all values should be negated. That is NNN, is really
-NN.N.

Data Processing Description

Dataset Processing Description

See the related objects sv120amcoords_0103, sv120pmcoords_0103 and sv120depths_0103 for NBP0103.

Deployment-specific processing description

<a href="http://globec.whoi.edu/jg/info/globec/soglobec/broadscale/2001/sv120coor...
sv120coords_0104</a> and
<a href="http://globec.whoi.edu/jg/info/globec/soglobec/broadscale/2001/sv120dept...
sv120depths_0104</a> for NBP0104

More information about this dataset deployment

Funding

Award Number	Funding Source
ANT-9910307	NSF Antarctic Sciences

Instruments

BIo-Optical Multi-frequency Acoustical and Physical Environmental Recorder II

Supplied Description:

These relative decibel values are the result of processing the NBP0104 and NBP0103 volume backscatter data from BIOMAPER-II at 120KHz.

Instrument Type

Generic Name: BIo-Optical Multi-frequency Acoustical and Physical Environmental Recorder II

Acronym: BIOMAPERII

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0007/

Generic Description:

BIOMAPER II is a set of sensors on a long aluminum frame that resembles the tail of a World War II airplane. A research vessel tows the instrument through the water on a specialized tow cable that sends power to the sensors and brings data back to the ship. People use BIOMAPER II to learn about phytoplankton and zooplankton over areas that are too large to study with the traditional net-and-microscope method. Whereas nets can sample areas up to about 5 meters (16 feet) on a side, BIOMAPER II can record data from 500 meters (1,640 feet) or more of the water column at a time. The instrument's standard suite of sensors were chosen for studying plankton: a five-frequency sonar system, a video plankton recorder and an environmental sensor system (ESS, like the one on MOCNESS). The ESS measures water temperature, salinity, oxygen, chlorophyll and light levels. BIOMAPER II also has room for attaching other instruments for specific uses. The instrument's official name is BIOMAPER-II: the BIo-Optical Multi-frequency Acoustical and Physical Environmental Recorder. The Roman numeral II indicates that it's a redesign of the original BIOMAPER, a prototype that was invented and tested in the mid 1990s. (more information).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruiseid	cruise identifier		cruise_id
year	year, e.g. 2001.		year
platform	ship, mooring, fixed location name		platform
timezone	per US GLOBEC, number of hours added to local time to convert to GMT		time_zone
decibel_returns_1	energy backscatter values group 1 of 20, -NN.N represented as NNN	relative decibels	Acc_bksctr
decibel_returns_2	energy backscatter values group 2 of 20, -NN.N represented as NNN	relative decibels	Acc_bksctr
decibel_returns_3	energy backscatter values group 3 of 20, -NN.N represented as NNN	relative decibels	Acc_bksctr
decibel_returns_4	energy backscatter values group 4 of 20, -NN.N represented as NNN	relative decibels	Acc_bksctr

Database

Contribute Data

Dataset: acoustic backscatter120 kHz
Deployment: NBP0104

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Database

Contribute Data

Dataset: acoustic backscatter120 kHzDeployment: NBP0104

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Dataset: acoustic backscatter120 kHz
Deployment: NBP0104