About time series collection data

The Time series collection data type may be used for raw variables derived from a *.table.csv file, or by variables created by the Collate time series operator.

The Transmission time series collection data type is used for such variables derived from supported Simrad EK80 data.

Time series collection variables

Both kinds of time series collections are made up of a set of time series.

Both kinds of time series collections are made up of a set of named time series that share common date and time values. Each series has value measurements and (optionally) status values.

The collection variable can be displayed as a table.
Pairs of time series from the collection may be displayed as a graph or a Time series scatter plot.
Settings that affect time series collections are on the Variable Properties dialog box.
Time series collections can be exported to a single *.table.csv file.

Note: Platform source depends on the collection type: Custom time series table (raw) and virtual collections use the collection’s Platform property; Transmission characteristics use the associated transducer’s platform. Single time series derived from a collection inherit the collection’s platform.

Exporting time series collections

You can export a time series collection variable to a single *.table.csv file:

From the variable or table using Export data.
Using the Measurements – CSV exporter when the operand is a time series collection.

Exported *.table.csv files can be added back to a fileset to recreate the collection. See Exporting time series data for more details.

Time series select operator

A single time series may be derived from a time series collection variable using the Time series select operator. The operator may be configured to output data with a Standard data type which has units, and associated interpolation and no-data handling methods. The alternative option is to use an Unspecified data type with a selected Interpolation mode and associated no-data handling method. Unspecified data types are supported by the Display page settings for Unit name and Unit short name that are used by graphs and tables.

Note: Assign a platform to the collection (via the variable’s Platform property) to provide position context. Single time series derived with Time series select inherit the collection’s platform and can display an alongtrack plot when the platform is connected to a GPS variable.

Virtual unspecified time series

Unspecified data type outputs a virtual unspecified time series variable with a unitless data type that is paired with a specified interpolation method. For further information on interpolation methods refer to the Time series select page.

The export to a CSV file for virtual unspecified time series data outputs a *.custom.csv file - flagging the unitless nature of the data.

Transmission time series collection variables

The active transmission impedance of a transducer may vary from the manufacturer's measured value due to physical or environmental changes at or near the transducer.

The ICES CRR326 Calibration of Acoustic Instruments report notes that changes in transducer impedance may indicate:

echosounder performance
the physical integrity of a transducer or transducer cabling
the state of the transducer face (e.g., biofouling or entrained air in the water)

Some hydroacoustic systems record active transmission characteristics and save them to a file.

Echoview supports Simrad EK80 CW (continuous wave) active transmission characteristics per ping saved by the following systems:

EK80 WBAT and EK80 WBT systems that save characteristics with complex samples
EK80 WBT systems that save characteristics with power/angle samples starting with v21.15 of the EK80 acquisition software (released in 2022). Note: power/angle data acquired with earlier versions did not include impedance information.

Notes:

Transducer impedance tolerances and manufacturer values are specified in the transducer datasheet and reference manual.
WBT includes WBT, WBT Tube, WBT Mini, and WBT Portable—all run via EK80 acquisition software.
WBAT systems use acquisition software known as “Mission Planner”.
Echoview may fail to read transmission characteristics from WBAT files dated around 2017–2018.

A Transmission time series collection is a raw variable that contains per-ping transmission characteristics recorded by a supported echosounder. These variables include ping time and one or more impedance-related metrics (e.g., resistance, reactance, power).

Platform source: from the associated transducer. Transmission time series derived with Transmission time series select inherit the platform via the collection’s transducer.

If the transducer’s Platform is set to None, the variable becomes unavailable.

You can reassign the associated transducer using drag-and-drop in the Dataflow window or via the Console and command interface.

Transmission time series select operator

The Transmission time series select operator extracts a specific transmission metric—such as power, frequency, or impedance—from a Transmission time series collection variable. It outputs a Transmission time series that can be analyzed, graphed, or processed using time series tools (e.g., smoothing, time series range bitmap).

Note: Statistics reported by this operator may differ from those shown in the Transducer Diagnostics section of the Simrad EK80 acquisition software.

Virtual transmission time series

The export to a CSV file for virtual transmission time series data outputs a *.csv file.