Exporting data or underlying data

The data values exported will depend on the type of variable from which you are generating the export, e.g. Sv values will be exported from a Sv variable, TS values from a TS variable. Underlying data values exported will depend upon the file format and what is stored in the data file.

All values are exported with one ping per line in a .csv file.

Notes:

  • Some acoustic data may also be exported to the MATLAB format (*.mat).
  • See Text data files for information on how you can use these exported data files in Echoview again.
  • This type of export is not available from all acoustic variables. See Export file formats for a listing of different data exports from acoustic variables.
  • Exclusions set on the Analysis page of the Variable Properties dialog box are applied to exported data but are not applied to exported underlying data. Excluded samples are handled as no data values.
  • The Live Export operator allows the export of data in real time while live viewing.
  • Echoview doesn't support the export of underlying data for EVD data files added to a fileset.

To export data values for a Dataflow object

  1. On the Dataflow window, click an object, on the right-click menu click Export, Data Values...
  2. On the export dialog box, specify the Export options.
  3. Click Export...

To export data and underlying data from single beam, split beam or dual beam variables

To export data values or underlying data for an echogram:

  1. On the Echogram menu, point to Export, and then click Values to CSV... or Underlying data...
  2. On the export dialog box, specify the Export options.
  3. Click Export...

To export data values or underlying data from a selection:

  1. Make a selection using the vertical band tool vertical selection tool.
  2. On the Shortcut menu (right-click), point to Export Selection, and then click Values to CSV...

To export data values from a region:

  1. Select the region.
  2. On the Shortcut menu (right-click), point to Export Region, and then click Values to CSV...

Notes:

To export data and underlying data from multibeam variables

You can export the following values for all pings or a selection of pings:

  • echogram data values (data values from the current echogram that were derived by Echoview from the underlying data, e.g. Sv, unspecified dB values)
  • underlying data values (the values read from the data file)
  • multibeam bottom detections

Note: Underlying values cannot be exported from variables that were beamformed in Echoview.

To export data values from a multibeam echogram:

  1. On the Echogram menu, point to Export, and then click Underlying data..., Values to CSV... or Bottom detections...
  2. On the export dialog box, specify the Export options.
  3. Click Export...

Note:

To export velocity data from current velocity variables

To export velocity values from current velocity echogram data:

  1. Display a current velocity echogram.
  2. On the Echogram menu select Export, Velocity Values to CSV...
  3. On the export dialog box, specify the Export options.
  4. Click Export...

Note: Cancel export is available for current velocity value exports.

Echogram data export file formats (*.csv)

Data values (Sv values, TS values, dB values, linear values, boolean values, angular positions, color values, power values, current velocity values) can be exported from echograms to .csv files.

The first line of the .csv file lists the names of the variables that are exported (these will be used as column headings if the file is loaded into a spreadsheet program). No column heading is provided for the list of data values. Each subsequent line contains the value for each variable for a single ping and the data value for each sample in the ping.

Single beam, split beam, dual beam and current velocity data value exports

Data can be exported for an entire echogram, a region, or a selection made using the vertical band tool vertical selection tool. The following data are exported.

Variable

Description

Ping_index

Sequential ping number

Note: Echoview numbers pings sequentially beginning with 0 for the first ping in an echogram.

Distance_GPS

Distance (nmi) from the first GPS fix in the data file.

Distance_vl

Distance (nmi) traveled according to the vessel log at the time the ping was transmitted.

Ping_date

yyyy-MM-dd

Ping_time

HH:mm:ss

Ping_milliseconds

The millisecond component of Ping_time.

Latitude

degrees

Longitude

degrees

Depth_start

m

Depth_stop

m

Range_start

m

Range_stop

m

Sample_count

Number of samples to follow

List of data values

Data value for each sample (separated by commas)

Note:

  • For "color" variables, the red, green and blue color intensities of each data point are exported as a single number. The exported number is a decimal representation of a six digit hexadecimal number 'bbggrr'; where 'bb' represents the intensity (0-255) of blue, 'gg' represents the intensity of green and 'rr' represents the intensity of red.
  • The units for the data values are not exported to the file. This can be found on the Details dialog box instead.
  • For "boolean" variables, each data point is represented by 0 or 1 (for false and true respectively). 0.0 and no data are handled as false. All other values are handled as true.

Notes:

  • When exporting data values for a region, the data output covers the bounding rectangle of the region. A special export value is output when the relevant point is outside the region. Prior to Echoview 12, there was a bug which was not accounting for points outside the rectangle, when exporting angular positions data.
  • For export of angular positions data, two angles are exported for each data point in the water column: minor-axis (alongship) angle, and major-axis (athwartship) angle.
  • The range and depth of each sample is not exported but can be calculated from exported data, see Calculating range and depth from exported data.
  • Some acoustic data may also be exported in the MATLAB format (*.mat).
  • Exported Sv, TS, angular position, boolean or linear values from vertical selections or whole echograms (but not regions) can be added as separate data files into an EV file and read as raw variables. These files will have an additional file extension describing the data type: .sv.csv, .ts.csv, .angles.csv, .linear.csv, .boolean.csv respectively.
  • The exported latitude and longitude values are the latitude and longitude of the GPS antenna at time of ping. As a result, the depth that is exported will only represent the line depth at the exported latitude and longitude if the transducer was located at the same point on the platform as the GPS antenna and was pointing straight down. The latitude and longitude of the line cannot be corrected for transducer geometry as lines are not related to a specific transducer or echogram.
  • Exported Sv values from complex Sv data represent the magnitude of the power scaled by Sv algorithm values (that account for TVG, two-way absorption and system and transducer constraints).
  • Exported TS values from complex TS data represent the magnitude of the power scaled by TS algorithm values (that account for TVG, two-way absorption and system and transducer constraints).
  • Exported Power values from complex power data represent the magnitude of the power scaled by power algorithm values (that account for TVG, two-way absorption and system and transducer constraints).

Multibeam data value exports

Data values from all types of multibeam variable can be exported to .csv files. The export can be for an entire echogram or for a range of pings selected from the Export Data - Select Range of Pings for Export dialog box.

The first line of the file is a header row that contains the names of the variables that are exported (see below). The remaining lines contain the corresponding variables for a single ping.

Variable

Description

Ping_index

Sequential ping number

Note: Echoview numbers pings sequentially beginning with 0 for the first ping in an echogram.

Distance_gps

Distance (nmi) from the first GPS fix in the data file

Distance_vl

Distance (nmi) traveled according to the vessel log at the time the ping was transmitted

Ping_date

The date (yyyy-MM-dd) on which the ping was transmitted

Ping_time

The time (HH:mm:ss) at which the ping was transmitted

Ping_milliseconds

The millisecond (0..999) at which the ping was transmitted

Latitude

The latitude (degrees) of the GPS antenna at the time the ping was transmitted

Longitude

The longitude (degrees) of the GPS antenna at the time the ping was transmitted

Heading

The heading of the platform at the time the ping was transmitted

Note: Heading values are taken from the heading variable selected on the Attitude page of the Platform Properties dialog box.

Range_start

Range (m) of the nearest sample in the ping (measured along the beam-axis)

Range_stop

Range (m) of the farthest sample in the ping (measured along the beam-axis)

Sector_angle

Angle (degrees) scribed between the outer edges of the two outer beams.

Number_of_beams

Number of beams in this ping

Samples_per_beam

Number of samples in each beam of this ping

Ping_mode

A number identifying the ping mode.

Variable_name

The name of the variable which was exported.

Full_sector_angle

The description of a beam subset.

Full_sector_beam_count

First_beam_number

Tilt_angle

The tilt angle of the beam.

Bearing_angle

The bearing angle of the beam.

Datafile_ping_number

The number, if any, assigned to the ping in the original data file from which Echoview read the data.

List of datafile values

If and only if data is being exported from a raw variable of ping mode 3, 4 or 5 (H-, V-, S-mode) in Furuno .fsv files then certain values read from the data file will be exported here in a series of columns headed "datafile_X" where X is the name of the variable in the data file.

Note: See Furuno FSV-30 (Research version) data format note.

Target_lock_beam

The number of the beam in the beam in the target-locked variable if any.

Note: This is only exported from variables with ping mode 3 or 4 (H- or V- mode).

Ping_group

A number identifying the ping group.

Note: This is only exported from variables with ping mode 3 or 4 or 5 (H- or V- or S- mode).

List of data values

Note: No title in the header row of the file

On the remainder of this line, the data value for each sample arranged as follows (for x+1 samples and y+1 beams):

<beam0 sample0>, <beam1 sample0> ... <beamy sample0>,

<beam0 sample1>, <beam1 sample1> ... <beamy sample1>,

...

<beam0 samplex>, <beam1 samplex> ... <beamy samplex>

Note:

  • For "multibeam color" variables, the red, green and blue color intensities of each data point are exported as a single number. The exported number is a decimal representation of a six digit hexadecimal number 'bbggrr'; where 'bb' represents the intensity (0-255) of blue, 'gg' represents the intensity of green and 'rr' represents the intensity of red.

  • For "multibeam boolean" variables, each data point is represented by 0 or 1 (for false and true respectively). 0.0 and no data are handled as false. All other values are handled as true.

Note:

  • The file extension provides information about the values that were exported:

Data type

File extension

magnitude (raw - not beamformed)

.csv+

phase (raw - not beamformed)

.csv

magnitude (beamformed)

.mag.mb.csv+

phase (beamformed)

.phase.mb.csv

angular position pings (formed beams)

.angle.mb.csv

Sv

.sv.mb.csv+

unspecified dB

.db.mb.csv

TS

.ts.mb.csv

Boolean

.boolean.mb.csv

color

.color.mb.csv

+Sv and magnitude variables may also be exported in MATLAB format (*.mat).

  • If and only if data is being exported from a raw variable of ping mode 3, 4 or 5 (H-, V-, S-mode) in Furuno .fsv files and that data file contains target detections, then a separate file with the extension "(datafile targets).csv" will be exported which contains the target information. See Furuno .fsv files for more information.

See also

Exporting data values
Text data files

Underlying data export file formats (*.csv)

Underlying data can be exported to .csv files from most Echograms (a notable exception is variables produced by Echoview's beamformer).

Single beam, split beam and dual beam underlying data exports

Underlying data values from Sv, TS, angular position variables can be exported to .csv files. The export can be for an entire echogram or a selection made using the vertical band tool vertical selection tool.

The first line of the .csv file lists the names of the six data properties that are exported (these will be used as column headings if the file is loaded into a spreadsheet program). No column heading is provided for the list of data values. Each subsequent line contains the value for each variable for a single ping and the underlying data value for each sample in the ping.

The following data are exported.

Data property

Description

Ping_index

Sequential ping number

Note: Echoview numbers pings sequentially beginning with 0 for the first ping in an echogram.

Depth _start

m

Depth _stop

m

Range_start

m

Range_stop

m

Sample_count

Number of samples to follow

List of data values

Sample values (separated by commas)

Note: For raw complex variables, the export outputs a single complex value for each sample. The value is the average of the complex values for the sample, read from the data file. The data for each ping is output as: Sample 1 Real, Sample 1 Imaginary, Sample 2 Real, Sample 2 Imaginary ...

Notes:

  • When exporting data values for a region, the data output covers the bounding rectangle of the region. A special export value is output when the relevant point is outside the region. Prior to Echoview 12, there was a bug which was not accounting for points outside the rectangle, when exporting angular positions data.
  • For export of angular positions data, two angles are exported for each data point in the water column: minor-axis (alongship) angle, and major-axis (athwartship) angle.
  • The range and depth of each sample is not exported but can be calculated from exported data, see Calculating range and depth from exported data.

Multibeam underlying data exports

Underlying data values from all multibeam variables not formed by Echoview's beamformer can be exported to .csv files. The export can be for an entire echogram or for a range of pings selected from the Export Underlying Data - Select Range of Pings for Export dialog box.

The first line of the .csv file lists the names of the six data properties that are exported (these will be used as column headings if the file is loaded into a spreadsheet program). No column heading is provided for the list of data values. Each subsequent line contains the value for each variable for a single ping and data values for each sample in the ping.

Data property

Description

Ping_index

Sequential ping number

Note: Echoview numbers pings sequentially beginning with 0 for the first ping in an echogram.

Range_start

m

Range_stop

m

Sector_angle

The angle of the sample from the transducer axis

Number_of_beams

The number of beams in the multibeam echogram.

Samples_per_beam

Number of samples per beam in the echogram.

List of data values

Note: No title in the header row of the file

Depending on the variable and echosounder from which the data was collected, data may consist of:

  • magnitude data: signal strength of each sample.

  • amplitude and phase data: alternating magnitude and phase information for each sample.

  • in-phase and quadrature data: alternating in-phase and quadrature components of the complex voltage signal for each sample. The signal magnitude is the square root of the sum of the component squares and the phase is the trigonometric tangent of the quadrature to in-phase component ratios.

To determine which format your echosounder stores, see Echosounder data files

The data values are ordered as follows:

Each line contains the sample values for a whole ping. If the ping data is seen as a matrix with one column per beam and one row per distinct sample range, then the data are written one row at a time to the data file (on the one line). If the data are complex then the values are further, written as pairs (in-phase and quadrature values or magnitude and phase values respectively).

Thus, samples are ordered from the lowest range across each beam, i.e., they are reported in the following order:

range0-beam0, range0-beam1, ... range0-beamN,
range1-beam0, range1-beam1, ... range1-beamN,
range2-beam0, range2-beam1, ... range2-beamN,
rangeM-beam0, rangeM-beam1... rangeM-beamN for N-1 beams and M-1 ranges.

Notes:

  • Multibeam underlying data can only be exported if the ping mode is 2.

See also

About exporting data