Data Formats

All information about the data can be found in the header of the downloaded file as well as in the accompanying metadata. The time format is in decimal days from the year that it was requested. For example, the excerpt below shows a typical CSV file available from the VENUS download data page. The time (first column) is the decimal day from the Start Time 2010-01-01 00:00:00 given in the header of the file.

The returned mat file has a structure called venusdata. All the information is returned in the structure as follows:

Click here for the extraction program “venusExtract.m”…

An example of the returned matlab structure:

venusdata =

searchby: ‘INSTRUMENT’ (can be by instrument or water property)

starttime: ’2008-02-27T00:00:00.000Z’ (search start date/time)

endtime: ’2008-09-27T23:00:00.000Z’ (search end date/time)

deviceinfo: [1x1 struct] (all device information)

locationinfo: [1x1 struct] (all location information)

data: [1x1 struct] (all data)

waterpropertynames: {‘Conductivity’} (names of water properties in data)

The Device Information:

venusdata.deviceinfo =

devicedates: {’2008-02-27T00:00:00.000Z’ ’2008-09-27T00:00:00.000Z’} (Active device dates)

devicecode: {‘SBECTD16p4997′} (VENUS device code)

devicename: {‘Seabird CTD 16 plus 4997′}

sampleperiod: [7.3347e+005 7.3368e+005 6.9444e-004] (sample date from in matlab time, sample date to in matlab time, sample rate in matlab time)

The Location Information:

venusdata.locationinfo =

region: ‘Saanich Inlet’ (VENUS region)

nodelocation: ‘Central Node’ (VENUS node location)

sitedates: {’2008-02-27T00:00:00.000Z’ ’2008-09-27T00:00:00.000Z’} (Active site dates)

sites: {‘VIP-07′} (All sites queried during search)

latitude: 48.6512 (All site latitudes queried during search)

latitudeunits: ‘decimal degrees N’

longitude: 123.4861 (All site latitudes queried during search)

longitudeunits: ‘decimal degrees W’

depth: 96 (Mean depth of site)

depthunits: ‘m’

The Data:

venusdata.data =

matlabtime: [305380x1 double] (data timestamp)

Conductivity: [305380x1 double] (data)

Conductivity_units: ‘S/m’

Conductivity_QC_flag: [305380x1 double] (date quality control)

The Imagenex 881A Sector (imaging) and Profiling devices area multi-frequency digital scanning sonars.
http://www.imagenex.com/Products/881A/881A_Imaging/881a_imaging.html
http://www.imagenex.com/Products/881A/881A_Profiling/881a_profiling.html

We offer the following data formats on our Download Data page:
Daily 81A files
Separated Scan 81A files
Daily Space Delimited Text files
Separated Scan Space Delimited Text files

The space delimited text files are raw HEX format. They are for users who are familiar with these devices and have experience in data processing and analysis. In Separated Scan Space Delimited Text files, each scan is parsed out of the raw data and stored in its own file. For example, if a user requests Imagenex 881A Sector 3899 data on May 17 2008 and selects the Separated Scan Space delimited Text file format, the user will receive 24 files named like:
IMG881A3899_20080517_scan00.txt
IMG881A3899_20080517_scan01.txt
IMG881A3899_20080517_scan02.txt
IMG881A3899_20080517_scan03.txt
IMG881A3899_20080517_scan04.txt
IMG881A3899_20080517_scan05.txt
IMG881A3899_20080517_scan06.txt
IMG881A3899_20080517_scan07.txt
IMG881A3899_20080517_scan08.txt
IMG881A3899_20080517_scan09.txt
IMG881A3899_20080517_scan10.txt
IMG881A3899_20080517_scan11.txt
IMG881A3899_20080517_scan12.txt
IMG881A3899_20080517_scan13.txt
IMG881A3899_20080517_scan14.txt
IMG881A3899_20080517_scan15.txt
IMG881A3899_20080517_scan16.txt
IMG881A3899_20080517_scan17.txt
IMG881A3899_20080517_scan18.txt
IMG881A3899_20080517_scan19.txt
IMG881A3899_20080517_scan20.txt
IMG881A3899_20080517_scan21.txt
IMG881A3899_20080517_scan22.txt
IMG881A3899_20080517_scan23.txt

Here is an example of the HEX data in file IMG881A3899_20080517_scan06.txt:

20080517T060000.141Z 49 4d 58 10 41 01 01 05 00 00 7c 01 17 15 11 0b 06 07 0a 0c 0c 0b 08 03 02 04 05 05 04 04 04 05 04 03 02 04 07 0a 0b 0b 0a 09 06 03 03 02 02 02 02 01 00 01 01 02 02 02 02 02 02 01 00 02 03 04 05 05 05 05 05 04 04 03 04 04 05 06 07 08 08 08 08 07 07 07 07 07 07 07 06 06 06 07 08 0a 0c 0d 0d 0d 0d 0b 09 06 03 03 06 09 0b 0d 0e 0f 0f 0f 0f 0e 0e 0e 0f 0f 0f 0f 0d 0b 09 0a 0b 0d 0e 0e 0d 0c 0a 09 08 07 06 05 05 04 04 05 06 08 09 0a 0b 0a 09 07 05 04 08 0c 0f 12 13 13 12 0f 0b 06 01 03 05 05 04 03 06 09 0c 0e 0f 0f 0d 0b 08 04 03 07 0b 0d 0e 0d 0b 09 06 06 08 0a 0a 0a 09 08 06 05 05 04 03 02 04 07 09 0a 0a 09 07 03 03 08 0b 0d 0d 0c 0a 07 04 03 06 08 0a 0b 0c 0c 0b 0a 07 04 02 02 03 03 01 02 06 0a 0e 11 13 15 15 15 13 11 0e 0b 08 06 04 03 02 02 03 03 03 04 04 05 06 07 07 07 07 06 7f 26
20080517T060001.150Z 49 4d 58 10 41 7e 00 05 00 00 7c 01 03 03 03 04 05 06 07 07 08 08 09 09 08 08 07 06 05 03 02 03 05 07 09 0a 0a 0b 0b 0a 0a 0a 0a 09 09 08 07 04 04 03 05 06 08 09 09 0a 09 09 08 07 05 05 05 05 06 05 05 04 03 03 02 03 03 04 05 06 07 08 08 08 08 07 06 04 02 03 05 05 05 04 03 06 0b 0f 13 16 16 16 15 12 0e 0a 06 03 01 02 03 06 09 0c 0f 10 12 12 11 10 0e 0b 08 04 04 09 0e 13 17 19 19 17 13 0e 09 08 0c 0f 12 14 15 15 15 13 11 0f 0c 09 06 06 08 0a 0c 0c 0c 0b 0a 09 09 0a 0b 0c 0d 0e 0e 0e 0d 0c 0b 0a 0a 0b 0b 0c 0d 0e 10 11 11 12 12 12 12 11 10 0e 0c 0a 07 04 03 05 08 0b 0d 0e 0e 0e 0e 0c 0b 09 07 06 05 05 06 06 06 06 05 04 04 05 06 06 05 04 01 04 09 0c 0f 11 12 13 12 11 0f 0d 0a 08 05 03 01 03 04 05 05 05 05 04 03 02 02 03 04 04 05 04 04 04 04 04 05 06 08 09 0a 0a 0a 0a 08 07 06 05 7f 26

Daily Space Delimited Text files are in the same HEX format, but all the scans are in one file. If a user requests Imagenex 881A Sector 3899 data on May 17 2008 and selects the Daily Space delimited Text file format, only one file (IMG881A3899_20080517_daily.txt) will be returned.

81A files are the manufacturer’s native data format and readable by the software program win881A.exe (downloadable from the Imagenex website http://www.imagenex.com/Downloads/downloads.html). Daily 81A files contain all the data collected in one day and the scans are parsed out in Separated Scan 81A files – just like the text files with .81A extension. Here is a snapshot of Imagenex Sector 3899 data displayed using the win881A software:

The Sequoia LISST records transmission, pressure, temperature along with light intensity parameters that can be used to compute % optical transmission.

http://www.sequoiasci.com/products/fam_LISST_100.aspx

Data can be downloaded from the Download Data page as comma separated variable text files or MATLAB .mat files. These data products are presented in a cleaned up raw format i.e. instrument commands and bad data values are removed and data gaps are filled with evenly spaced NaN’s. Data from the LISST are collected in “bursts” – every 600s, 40 elements are collected (elements are ms apart).

Example of data from a comma separated variable text file:

Example of data from a MATLAB .mat file (structure lisstdata with some elements expanded):

LISST data are recorded in ‘Raw Data Storage Format’ (see page 55 of the LISST 100x user’s guide http://www.sequoiasci.com/products/fam_LISST_100.aspx). Here is a table for decoding the data from the user’s guide:

VENUS scalar and State of the Ocean data are now downloadable as an Ocean Data View 4 Generic Spreadsheet. Import this format directly into Ocean Data View for easy-to-create plots of VENUS data.

See the VENUS download data page or the State of the Ocean page for more details. See also the Ocean Data View home page for details on obtaining the software.

We are now offering RDI Acoustic Doppler Current Profiler (ADCP) data in RDI binary format. RDI binary data can be displayed and analysed using the RDI’s WinADCP software package.

The image above is a sample of ADCP data collected on October 28 2010, created using WinADCP. It displays east, north and vertical current velocities as well as average echo intensity from our Strait of Georgia East site at 170m.

Please visit our Download Data page and select “by instrument” to download ADCP data in RDI binary format. Here is the site information, instrument names and time periods where we have collected data from RDI ADCPs to help you with your selection criteria:

Strait of Georgia, East Node (170m): RDI ADCP 150kHz WH (SN 8497)
Sites:VIP-01/VIP-02/VIP-03/VIP-04/VIP-05
Data collected between 2008-Feb-29 to present.
 

Strait of Georgia, Central Node (300m): RDI ADCP 150kHz WH (SN 8580)
Sites: VIP-01/VIP-02/VIP-03
Data collected between 2009-Sep-24 to 2010-Aug-27.

Strait of Georgia, East Node: RDI ADCP 600kHz WH (SN 7992)
Site: DDL-01 (40m)
Data collected between 2008-Feb-29 to 2008-Sep-25.

Strait of Georgia, East Node: RDI ADCP 300kHz WH (SN 2940)
Site: DDL-03 (107m)
Data collected between 2010-Feb-20 to 2010-Mar-12.