Altimetry models
WOSS allows the user to create and simulate sea wave models. The altimetry framework supports time evolution.
Flat Model
The basic model is the Flat Altimetry model: it represents a flat sea surface.
Bretschneider Model
The Bretschneider Altimetry class implements the Bretschneider (ITTC two parameters) wave spectrum [1].
Its input parameters are:
- characteristic wave height [m] - H -
- wave period [s] - T -
Additional parameters are:
- range [m]
- range steps
- scenario depth [m]
The latter are automatically set by the WOSS framework.
Examples:
References:
- G. J. Komen et al., Dynamics and modeling of ocean waves. Cambridge University Press, 1994.
Time evolution modeling
Time evolution is supported by the following object/classes:
- woss::Woss - controls its evolution by querying a new SSP for the new time evolution quantum and by asking its woss::Altimetry to evolve.
- woss::Altimetry - performs an evolution of its mathematical model.
- woss::AltimBretschneider - generates a new realization of its statistical process.
Each class supports an independent time evolution quantum, measured in seconds, and the enabling/disabling of the feature, for the maximum flexibility.
The framework controls the time evolution through the following classes:
- woss::WossManager - the class now supports queries for a specific woss::Time object or for a specific number of seconds after the start of the simulation (woss::SimTime).
- woss::WossController - for each pair of tx-rx woss::Location the user can set a different woss::SimTime object.
- woss::WossDbManager, woss::WossDb - all databases now supports queries for a specific woss::Time object
- woss::CustomDataTimeContainer - A new template for custom db data has been introduced to properly support time evolution. This is best used for time dependent custom SSP data, as each returned value is an linear interpolation of the SSP related to the two most close Time values.
For a clarifying example please check out the related tcl file in ./samples/ directory.
Underwater Acoustic Transducers
DISCLAIMER
Federico Guerra and SIGNET lab do not endorse or recommend the use of any of the transducer listed below.
The copyright and property of of each transducer design is retained by the respective owners. The specifications of each transducer have been inferred from the transducer data sheets courtesy of the respective owners.
The list below is to be taken as a best-effort list, meaning that data has been taken from publicly avalaible documents, at the programmer's discretion.
This list is NOT final and will undergo continuous changes, aimed at providing support for an increasing number of transducers in WOSS.
If you would like any specific, not currently supported transducer to be included in WOSS, please feel free to contribute by sending transducer data (in the format mentioned below) to WOSS@.nosp@m.guer.nosp@m.ra-tl.nosp@m.c.co.nosp@m.m.
Technical description
WOSS accurately simulates power consumption, Sound Pressure Level (SPL) output, and vertical beam pattern of real acoustic transducers.
Transducers can be imported into simulation, and their beam pattern can be rotated or modified with a additive and a multiplicative constant to better suit the user needs.
Furthermore, woss::Location, WossPosition and WossWpPosition support simulation of dynamic orientation of the associated transducer to better simulate how AUV movements impact on transmission.
See woss::Location, WossPosition, WossWpPosition
Finally UwMPhyBpskTransducer and WossMPhyBpsk now supports array of transducers to permit spectral optimizations with realistic power computations and ray attenuation.
See Example with waypoints
Transducer file format (ASCII and binary)
The format of transducer .txt or .dat file can be changed by the user (extending the woss::Transducer class) and is the followings (format, comments are inline and in italics):
BT-25UF transducer's type name
25000.0 10000.0 resonance frequency, -3dB bandwith around the resonance frequency
338 0.1 max input power [W], duty cycle in (0,1]
1.0 1.0 1.0 1.0 TVR precision [hz], OCV precision [hz], conductance precision [hz], beam pattern precision [dec degrees]
5 total number of TVR values
10000.0 120 frequency [hz], TVR [dB re uPa/V @ 1m]
23000.0 140
25000.0 140
38000.0 136
50000.0 135
4 total number of OCV values
10000.0 -197 frequency [hz], OCV [dB re V/uPa]
20000.0 -190
23000.0 -190
50000.0 -212
6 total number of conductance values
10000.0 10 frequency [hz], conductance [uS]
13000.0 180
23000.0 940
30000.0 410
40000.0 390
50000.0 590
14 total number of angles in the vertical/horiz beam pattern
-180 0 angle between [-180, 180] in decimal degrees, [dB]
-150 -1 if the transducer has conical or != toroidal symmetry
-120 -5 the rotation axis has to lie on angle = 0 axis
-105 -14
-75 -14
-60 -5
-30 -1
0 0
30 -2
60 -4
90 -5
120 -4
150 -2
180 0
Transducer's list
These are the currently available transducers in WOSS (in alphabetical order).
BTech Acoustics, LLC
BT-1RCL @ 28 kHz
Datasheet:
SPL:
Vertical beam pattern:
BT-2RCL @ 28 kHz
Datasheet:
SPL:
Vertical beam pattern:
BT-25UF @ 25 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC
ITC-2003 @ 5,9.5 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-2010 @ 1,2.5 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-2015 @ 1.8,2.8 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-2044 @ 8,14 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-2062 @ .44,1.4 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-3001 @ 17.5 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-3013 @ 12.5 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-3148 @ 12.5 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITC-3167 @ 11 kHz
Datasheet:
SPL:
Vertical beam pattern:
ITT
SB31CT @ 10 kHz
Datasheet:
SPL:
Vertical beam pattern:
Neptune Sonar Limited
NOTE: vertical beam patterns inferred from datasheets generic description. All Neptune transducers report only one value of conductance, SPL calculations could be inaccurate
T54 @ 13 kHz
Datasheet:
SPL:
Vertical beam pattern:
T186 @ 17 kHz
Datasheet:
SPL:
Vertical beam pattern:
T204 @ 54 kHz
Datasheet:
SPL:
Vertical beam pattern:
T216 @ 58 kHz
Datasheet:
SPL:
Vertical beam pattern:
T217 @ 25 kHz
Datasheet:
SPL:
Vertical beam pattern:
T218 @ 22 kHz
Datasheet:
SPL:
Vertical beam pattern:
RESON
TC1026 @ 36 kHz
Datasheet:
SPL:
Vertical beam pattern:
