Resample Multibeam

The Resample multibeam pings operator resamples the input variable using a fixed number of beams (with specified minimum/maximum beam angles) and a fixed number of datapoints (with specified start/stop range).

A mean, median, maximum, minimum or percentile resampling operation can be performed.

Notes:

Multibeam H-mode is not supported.
When custom beams are specified, the beams in the output ping are evenly spaced in the specified sector. This may introduce distortion in the data.
Warning: The Multibeam Roll at Transducer operator rotates the coordinates of multibeam pings. Resampling multibeam data that has had a Multibeam Roll at Transducer operator applied may produce output pings that are themselves rolled - i.e. the output resampled pings may not be aligned. Echoview displays a warning in this scenario.

Operand 1

Multibeam magnitude
Multibeam Sv
Multibeam TS
Multibeam unspecified dB

Settings

The Resample multibeam pings Variable Properties dialog box pages include (common) Variable Properties pages and these operator pages:

Operands page

Resample Multibeam page

Settings

Description

Resampling operation

Resample operations are performed in the linear domain. If the input was in dB, the result is converted back to dB.

Available operations include:

Mean
Outputs a weighted mean of the input samples. The weights of an input sample is the product of the range and beam width of that sample falling within the output sample area.
Minimum
The output sample is the minimum value of the overlapping input samples.
Maximum
The output sample is the maximum value of the overlapping input samples.
Median
The output sample is the median value of the overlapping input samples.
Percentile
The output sample is the Nth percentile value of the overlapping input samples.

Output mode

Select either of these Output modes from the dropdown menu:

Use geometry of the first ping for all pings
The operator resamples all input pings according to the properties (e.g., beam geometry, beam widths, number of samples, etc) of the first ping.
Custom
Tick the checkbox for each of these options to specify the parameters for the output pings.

The operator resamples all input pings according to your custom parameters.

Otherwise, leave the option(s) unchecked to use the input ping properties for that option.

Output range
Specify the Start range (m) and Stop range (m).

Number of samples per beam
Specify the number of datapoints comprising each beam.

Sector angle range
Specify the Maximum angle (degrees) and Minimum angle (degrees), corresponding to the start and end edges of the sector.

Maximum angle must be greater than the Minimum angle, and the difference between the two cannot exceed 180°.

The output beams are evenly spaced across the sector angle.

Number of beams
An integer number of beams.

The output beams are evenly spaced across the sector angle.

Resample Multibeam

Settings

Operands page

Resample Multibeam page

See also