ADCP current velocity data for CTD stations of the BROKE-West SurveyEntry ID: BROKE-West_ADCP
Abstract: The Acoustic Doppler Current Profiler (ADCP) data were acquired constantly over the duration of the Australian 2006 V3 BROKE-West survey. Data presented here are the results of 1/2 hour integrations of the cruise data from the start of the voyage in Fremantle, Australia, to the start of the return leg just north of Australia's Davis Station in Antarctica (-66.56S, 77.98E). North and eastward ... components of the current velocity are given for depths up to 300m below the surface along the ship track.
The shipboard ADCP is a continuous broadband recording device that operates over the duration of the voyage, ensonifying the water column once a second. As the instrument is fixed to the ship, it has a range of approximately 250m deep. Data from the shipboard Ashtek 3 dimensional GPS system is used along with bottom tracking data (when the water is shallow enough i.e. less than 250m) and automatically integrated into ADCP ping data to provide absolute current velocities.
The ship ADCP constantly and automatically collects and stores raw .rawdp binary files in ensembles of three minutes worth of pings. This is regularly automatically collated into larger .adp files containing data for several hours (200+ ensembles). This data are processed for use in analysis using specialist software provided by Mark Rosenberg (mark.rosenberg AT utas.edu.au) that integrates together data from the ADCP .adp files for periods (30 minutes in this case) over a give time (from cruise start to the 3-Mar-2006). This produces .any ASCII files. These ASCII files are read into the Matlab processing package using scripts provided by Sergeui Sokolov (sergeui.sokolov AT csiro.au) which then produces the .mat matlab data files covered by this metadata. ADCP data requires proper calibration with respect to ship motion, which were not carried out for this data set, and could cause significant change when processed properly after the voyage.
The processed ADCP file is given in matlab .mat format. All 1/2 hour integrations of ADCP data for BROKE-West from 3 days (31-dec-2005) before departure from Fremantle, to the 3-Mar-2006 are included, each column in each matrix or array representing an individual 1/2 hour integration in chronological order. There are numerous gaps in the data that occured when the ADCP crashed and was not immediately reset or when bad data prevented processing. The location can be identified by plotting a scatter plot of longitude vs latitude, and the times by plotting the julian date.
The matlab variables contained in the BROKE_West_ADCP.mat file are contained inside the adcp structure:
lon: Longitude (decimal degrees)
lat: Latitude (decimal degrees)
time: Each column gives the year month day and hour of collection of the corresponding columns in the other variables.
depth: Depth of each corresponding velocity value for each 1/2 profile. 60 fixed bin depths are given for each profile. (meters)
press: As for depth but given in db. (db)
u: Absolute current eastward component in ms-1 for each depth and profile.
v: Absolute current northward component in ms-1 for each depth and profile.
unav: Ship absolute eastward component in ms-1 for each profile
vnav: Ship absolute northward component in ms-1 for each profile
jtime: Julian date for each profile (julian days)
badvals: Indexes of anomolous latitude and longitude values
ADCP: Accoustic Doppler Current Profiler
IASOS: Institude of Antarctic and Southern Ocean Studies
CSIRO: Commonweath Scientific and Industrial Research Organisation
This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).
This data set description is a member of a collection. The collection is described in
Start Date: 2005-12-31Stop Date: 2006-03-03
Temporal Resolution: 1 second
ISO Topic Category
Quality There are numerous breaks in the constant 1/2 hourly record where ADCP crashes, switch offs, or bad data have prevented data complilation. Several bad values are present in the latitude and longitude data, where anomolous ship positions are indicated, these are flagged in the dataset.
ADCP data are given in half hour averages of raw ADCP one per second ping data.
A pdf document providing further information about the dataset is available for download at the URL given below.
Access Constraints These data are publicly available for download from the provided URL. Plus a word document providing further information about the dataset is available for download at the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference at the provided URL when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 820 kb
Distribution Format: pdf
Distribution Media: HTTP
Distribution Size: 2 MB
Distribution Format: matlab, text
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: +61 3 6226 2324
Email: ameijers at utas.edu.au
Institute of Antarctic and Southern Ocean Studies Locked Bag University of Tasmania
Province or State: Tasmania
Postal Code: 7001
Phone: +61 3 6232 5334
Email: andreas.klocker at CSIRO.au
1 Castray Esplanade CSIRO Marine and Atmospheric Research
Province or State: Tasmania
Postal Code: 7000
Meijers, A., Klocker, A., Bindoff, N., Williams, G., Marsland, S., 2010. The circulation and water masses of the Antarctic shelf and continental slope between 30-80E. Deep-Sea Research II, 57 (9-10), 723-737.
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2006-03-11
Last DIF Revision Date: 2014-01-10