Sphere2BeamPattern: Beam Pattern Estimates from Calibration Sphere Data

In dmwarn/Sphere2BeamPattern: Calculate Beam Pattern Parameters for Split Beam Transducers

Description

Estimate 3 dB beam angles, angle offsets, and TS gain using the formula employed by Simrad Lobe program. Creates graphs showing sphere TS across the beam and a summary text file that includes numerous pieces of information to help make the process reproducible.

Usage

Sphere2BeamPattern(UseEchoview = FALSE, filesetName = NULL)

Arguments

UseEchoview	Logical scalar indicating if the user wishes to use Echoview to automatically determine the fileset that includes the sphere data variable used to export the single targets. Default is FALSE, and if the default is used, the user must supply a fileset name.
filesetName	A character scalar giving the name of the Echoview fileset, which can be identified automatically by setting the UseEchoview parameter to TRUE. GetEVRawPaths.

Details

This software is intended to aid those attempting to estimate transducer beam patterns using tungsten carbide calibration sphere single target data. The function uses the optimization routine optim() to minimize RMSE of a modified Bessel function (Ona 1990, ICES, B:30 Sess. R.). Some users employ a two-dimensional polynomial.

1. Adjust theoretical sphere TS above based on calcaulated TS by entering water temp, sphere size, frequency, etc (see. southwest fisheries science center website...). here https://swfscdata.nmfs.noaa.gov/AST/SphereTS/

2. Select all, press 'Run' or hit ctrl-enter on the keyboard to run script.

3. Will be prompted to select an INPUT file. This should be exported single target TS data in .csv format. Only one file can be selected at a time. Select 'open'.

4. Check Calibration output folder and view plots.

5. Repeat as necesssary for all frequencies.

Value

Several items included text file (.txt), a csv file, and graphs are saved to a folder valled "Calibration OUTPUT" created by this function.

Seven different data frames are saved as objects in an Rdata file and are written to csv files in maindir:

• calculated TS.csv = the original spehre data input along with the sphere TS calculated with the estimated beam pattern.

• Observed vs Corrected plot - Along axis.png = a plot with original (from Echoview, default beam settings) and corrected sphere TS versus along-axis beam angle.

• Observed vs Corrected plot - Athwart axis.png = a plot with original (from Echoview, default beam settings) and corrected sphere TS versus Athwart-axis beam angle.

• Summary info.txt = a text file containing date, equipment identifiers and default parameters, the EV file name, the raw data files used, and the output of the beam pattern fitting process.

• TS gradient plot.png = bullseye plot of sphere targets in the acoustic beam with coloring according to the TS.

The files all have a prefix = the name of the sphere input data file.

dmwarn/Sphere2BeamPattern documentation built on Dec. 7, 2019, 12:26 a.m.