Sphere TS calculator

This program calculates the target strength (TS) of acoustic calibration spheres.

Developed by Gavin Macaulay.

Instructions

  • Set the appropriate sphere and environmental properties.
  • Choose the desired spot frequencies and frequency sweep limits.
  • Click on the Calculate button to produce a plot of the sphere TS.

    The TS will then be calculated over the frequency sweep range and plotted in a separate window. Both the averaged and unaveraged TS are plotted.

    The TS at the spot frequencies will be shown in a box in the plot window. The spot frequencies are always averaged. If the averaging bandwidth would cause the frequency to be less than zero, it is truncated at zero and the average TS value is flagged with an asterisk.

    Methods

    The sphere target strength is calculated using equations 6-9 of MacLennan (1981) between the given start and stop frequencies. An averaged TS is also calculated via a linear mean over the frequencies within the given bandwidth. The frequency resolution is set automatically to give a smooth plot in a short computation time.

    In addition, the bandwidth averaged TS at spot frequencies is calculated. This is done independently of the frequency sweep calculation.

    When the Calculate from T,S, and D option is ticked, the water sound speed and density are calculated using the TEOS-10 formulation.

    Acknowledgements

    The style and functioning of this program was modelled on the Matlab code developed by Dezchang Chu, NOAA.

    References

    MacLennan, D.N., 1981. The Theory of Solid Spheres as Sonar Calibration Targets. Scottish Fisheries Research Report No. 22, Department of Agriculture and Fisheries for Scotland.

    Copyright

    Copyright 2014 Gavin Macaulay

    This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along with with this program. If not, see www.gnu.org/licenses.