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SynSwath manual

" SynSwath is an useful tool,
illustrative, playfull, cool."

Introduction
Keyboard shortcuts
Tool Boxes
OMG/UNB Syn-Swath
Widget Application Launcher
Useful command lines
Boundlessly
References

Introduction

SynSwath is a synthetic swath sonar simulation package for training and applications developed by John E. Hughes Clarke, leader of Ocean Mapping Group at the University of New Brunswick. In-house 3-D graphical teaching tool was developed on Silicon Graphics workstation using openGL graphic libraries. It allows the user to visualise all the geometric relationships between acoustically steered line arrays on a dynamic hull (i.e. rolling, pitching, heaving and yawing).

This document contains examples of SynSwath images, description and explanation of keyboard shortcuts and other useful operational steps. Firstly, you need to find the file SynSwath_WORKS* (directory code/gl/demos/). SynSwath Tool Box and Display Window appear after writting SynSwath on the command line. Do these snapshots seem familiar? Remember illustrations from GGE 3353?

Notice: SynSwath crashes after hitting !

Keyboard shortcuts

Since SynSwath has a few unresolved bugs you may find some useful shortcuts. For example, the A key toggles the axes and transmitting beams with T (see Figure 1). Receiving beams can be displayed with R (see Figure 2); more shortcuts follow in the table bellow:

Keys are window sensitive !

Shortcut

    Meaning

A     display 3D axes

←
→     rotate image about Z-axis

↑↓     rotate image up and down

+-     zoom in / out

T     toggle transmitter beams

R     toggle receiver beams

B     toggle display product of T and R

Y     toggle beam pattern

E     toggle blue eye    (wire render, plate, axes)

W     toggle water state Figure 1: Transmitter, Axes.

S     object selection (nothing/ ship1/ EM 1000/ SBat 9001/ SBat 9002/     longitudinal array /transversal array/ mills “X”/ mills “T”/ ELAC/
    EM3000/SeaMARC II/ Bathyscan/ Disc/ Two row/ Three row/ Hugin/
    ROV/ 8125/     8101/ 8111/ EM3000D)

G
    rolling, pitching animation
    note: faster with wire render (Z)

Z     toggle wire render / full render

C     cone steering, B displays both cones (! do not steer so that they do not
    intersect - it crashes the program !)

M     dumped scene

X     toggle rays

V     toggle recording (.ppm files)

0     change axis colour

9     front view (green axis)

8     sideview (pink axis)

6     adds a little sonar to the object drawing ()

7     top view

1, 2     lighter / darker properties of object surfaces
Figure 2: Receiver, Axes, Cones, Water, BeamVect.

5
    middle looking

P     toggle plate (if there is some!)

I
    toggle acoustic illumination of plate

Q     quit the program (! SynSwath crashes after hitting !)

Tool Boxes

OMG/UNB SynSwath Tool Box

Basic SynSwath window is SynSwath Tool Box. By hitting "Apps", you get Widget Application Launcher.
!SynSwath crashes after clicking on "Load", "Man. Load" and "Wire Render"! Other icons have the same meaning as keyboard shortcuts described above.

SynSwath Tool Box Icons:

Wire Render Render / Full
! Window button usually crashes the program. Instead of the button click use shortcut Z !

Man. Load would load a manually generated beampattern file !BUT if doesn't exist, crashes program !

Water water level

BP both transmitter and receiver beams roll or do not roll with the ship

Axes displaying of 3D axes

Coupling Coupling On - beams move with ship / Coupling Off - beam does not follow the ships movement (roll 17º, pitch 25º, power 18 dB).

BeamVect 1 click: shows one beam vector; 2 hits: shows azimuth and depression angle; 3 hits: displays a plane with refraction solutions.
+ and - keys (in beamvect button box) will plot a refracted ray bending either up or down.

Plate Works if plate is imported (knowhow see bellow).

Rays Toggle Rays On / Rays Off

Cones steering cones

Widget Application Launcher

Widget Application Launcher offers various menues (e.g.beam patern) and submenues (e.g.Shading Options). Widget Application Launcher has the following menu:

beam pattern


model the beam pattern with help of polar plots (maximum response axes): transmitting , receiving , product of both (frequency 95kHz, PS beam steering 33º, FA beam steering 11º); interactive changes of frequency; along and across arrays; beam steering parameters, to use vernier spacing Illuminated Plate and Bottom Detection Window must be open.
The longer array length, the narrower beam. Fully functionality was never brought up (across arrays, sound speed).

Shading Opts leftover from previous 2D versions of this tool, does not work in this version

Circ. Plane circular plane, single beam echosounder (slow change arrow length)

Cont. Line continuous line

Disc. Line discontinuous line, proper steering

Multibeam multibeam pattern

mat.props.
       material surface property from OpenGL (beam pattern, cones: diffuse, ambient, specular, shiny)
note: does not work with plate (seabed is illuminated acoustically)

Light 1 instead of this button, use key 1

Light 2 instead of this button, use key 2

Rot.Seq.
       rotation sequence selection; "Do you pitch around original axis or around axis of actual ship?"

YPR
Tate Bryant Yaw, Pitch, Roll, this order is an official order used by ships and all world airplanes; roll around the axis which was heading and pitch changed

YPRo HIPPY Yaw, Pitch, Roll; roll around unpitched axis (Hanewell)

YRP Yaw, Roll, Pitch

PRY Pitch, Roll, Yaw

RPY Roll, Pitch, Yaw

RYP Roll, Yaw, Pitch

PYR Pitch, Yaw, Roll

sonar model
       sonar model select (mount roll and pitch tilt, mock beam spacing)
This assumes on the command line you have listed "-bf xxx -bf yyyyy -bf zzzz " etc... This means you are pre-loading a "beam footprint" model. Example exist for various common sonars - they specify EA or EDBS beam spacing, beam size, spacing and ping sequence.

Select beam footprint model selector

make mockup It allows you to make a crude beam model using the slider bars. This actually implements it.

plt.sel.
       select imported plate

cone in cone
       tests non orthogonal cone alghorithms (! do not steer so that they do not intersect - it crashes the program !);
translations and rotations: TX and RC roll, pitch and yaw, TX orientations and RC deltas in RPY directions

CONES
display cones

PLANE display horizontal plane of transducer

JOHN This is historic - these are two versions of code to implement the rotations and calculating the final beam vector.

JONB this one does NOT exactly match the intersection of the two cones - i.e. not conforming to openGl math.

---- nothing

debug nothing

currents
       ADCP currents widget
An only partly finished widget - have to load a vertical profile of current vectors using the "-currents" command line option. It reads it a sequence of ADCP vertical velocity profiles and you can then make an animation showing the ADCP current field evolving over time.

Temp - not implemented

Salinity - not implemented

Backscatter - not implemented

Velocities - not implemented

LBL
       Long Baseline Transponder Array Control
A widget to display LBL geometry can change the location (and presence) of each one of the LBL transponders as well as the location and depth of the target. Then ranges from each target are calculated and the intersection of each sphere is displayed.
SLIDER BARS ---
target x-y-z is movable
click on the list of each transponder to select - then use X-Y-Z slider bar to move.
space bar on each transponder turns it on and off.

spheres toggle spheres

rays toggle rays to the target

P.depth This shows how a pressure gauge on the tracked hydrophone will solve for the depth - often LBL geometry is so flat it reduces to a 2D solution and you can't solve for the vertical very well.

target toggle target

cone steer
       cone steering demonstrations
This widget shows how active motion stabilisation is implemented.
! Have to use an ASCII motion time series ! >synSwath -ts gggggg
                                                                         get one from here: ggggg
SLIDER BARS ---
Compensation angle , when pitch stabilising is the elevation angle when the pitch stabilisation is perfect. Default is at Zero, ie. all other beams are OVER pitch compensated. Bellow 35-40° the nadir will be under compensated, 35-40° perfect, and > 35-40° is over compensated.
Max Steering Angle - for yaw or pitch stabilsation. This is the max steering that will be implelented on the transmitter. For demo purposes it is good to increase this form the default 15 to ~ 70°.
Angular Sector - starts off as a 120° sector (+/- 60°). User can change it to whatever she/he likes.
Also need to have the Animation widget up where you choose to turn on/off Yaw/Pitch/Roll stabilisation.

Single 1 Sector Default - only 1 transmit sector with only one steering angle allowed.

Single 3 Sector e.g. shallow EM300 / EM120 or EM710

Twin 2 Sector e.g. Hydrosweep MD

Twin 4 Sector what Fansweep could do BUT IT DOESN'T

Single 9 Sector e.g. deep EM300/EM120 (used in Labrador Sea)

draw history together with Go icon in Animation window

Thomson - Sim Cycles through - Single swath - Thomson SeaFalcon (7 swaths shown but only really 5) - then 2 swath EM710 and finally 8 sectors of the new Fansweep 30. / / /

MRU demo
       Seatex MRU-6 (serial port connection) sensor outputs to the computer screen.

Objects
       object selection menu (the same as keyboard S). Hitting the point in the middle will return object to default size. Hold left mouse button to roll, pitch etc. the object and to move green axis.

Plate
       rotate, roll, pitch, expand, vertically exaggerate (sun illuminate with +- buttons), middle mouse click, arrows buttons
when you are on the window with mouse, + - keys serve as a vertical distance from the ship

Phase
phase transmit - receive product

Int.
intensity transmit - receive product

Time
!!WRONG!! !!WRONG!! Time Off ! works just together with Bottom Detection Window !

Centre

Edge

Select
default closes Plate Window

+ / - bt.
bottom type; first minus / second minus / plus

+ / - sun
sun intensity

Bot.Det.
       interactive bottom detection window ; horizontal axis is TIME; lowest part in green displays INTENSITY (time of bottom detection) with BINS in vertical axis (up and down arrows for scaling); middle part in red is PHASE with vertical axis 0 - 360º; upper part of window serves as a display of ZOOMed intensity) which works only after Illumination, or with GO button in Animation menu, note: assumption is an imported plate (see bellow)

Ang.Resp.
       if you keep mouse arrow on the "Noise On", you can increase or decrease noise amount with up and down arrow keys corrected for spherical spreading

AR
Angular Response; AR Off is radiated intensity (much smoother!), no graph in AR Window;
-50 dB / -80 dB

BT

Shd.
shading turns yellow when unimagable

Noise
Noise On / Noise Off

Multiples

Rayleigh

Animation
       time series of roll, pitch, heave, heading and time; faster when beam pattern off; !do not animate with plate!

calc.

roll stab unstabilized and stabilized roll

pitch stab unstabilized pitch ; mechanically better than electronically

Gyro stab stabilize Gyroscop

Dump INSON

--GO-- START button for recording; number of samples saved

Record automatic recording of .ppm images in intervals of seconds

Mpitch stab stabilize pitch movement if there is some waving

ADCP
       Acoustic Doppler Current Profiler
A widget to explain the workings of an ADCP - not entirely finished.

beam patterns
display beams of ADCP transducer

beam vectors

currents
adds paralell current layers to the water column

bottom mask

Ref. Frame
       display reference frame of used object; keyboard shortcut: SPACEBAR
note: After klicking sensor play with its layout (pressure gauge, subbotom profiler, sidescan, GPS anntenna).

levers
Levers On / Levers Off

transparency
Transparency On / Transparency Off

default ship
display ship

ROV
display ROV

AUV
display AUV

sensor coords
display sensor coordinates

Useful command lines

How to import your plate?
>synSwath -plate darley
this command requires darley.r4, darley.sun and darley.BT* (renamed extention of 8bit file) files where darley is name prefix
>synSwath -ts mont_211_24.merged.ascii -level 1.0 -plate darley

    How to take a screenshot?
>import example.jpeg

    How to resize an image?
>convert -resize 200 example.jpeg example_smaller.jpeg

   How to label an image?
>convert -font helvetica -fill blue -draw "text 10,15 'SynSwath OMG/UNB'" example.jpeg example_labeled.jpeg
>xv example_smaller.jpeg

    Screen resolution of 3D window can be changed to 600 times 600 pixels with:
>synSwath -winsize 600 600

Boundlessly

The sonar parameters, including beam width, beam steering, side lobe suppression are mathematically modelled and the resulting 3D beam pattern can be projected onto a convenient regular terrain model to illustrate ensonification patterns. The bottom detection time series can be derived from that illumination pattern and noise added to simulate the bottom detection process.

References

SynSwath - a synthetic swath sonar simulation package for training and research applications
http://www.omg.unb.ca/SYNSWATH/OMG_UNB_SynSwath_top.html

GGE 4053 Hydrographic Surveying I
http://www.omg.unb.ca/~jhc/HYDRO_I_97/

In the time I wrote this manual JHC was still looking for proper model of ship for SynSwath main window. Do not hesitate to bring him some!

keta512@yahoo.com

Wire Render	Render / Full ! Window button usually crashes the program. Instead of the button click use shortcut Z !
Man. Load	would load a manually generated beampattern file !BUT if doesn't exist, crashes program !
Water	water level
BP	both transmitter and receiver beams roll or do not roll with the ship
Axes	displaying of 3D axes
Coupling	Coupling On - beams move with ship / Coupling Off - beam does not follow the ships movement (roll 17º, pitch 25º, power 18 dB).
BeamVect	1 click: shows one beam vector; 2 hits: shows azimuth and depression angle; 3 hits: displays a plane with refraction solutions. + and - keys (in beamvect button box) will plot a refracted ray bending either up or down.
Plate	Works if plate is imported (knowhow see bellow).
Rays	Toggle Rays On / Rays Off
Cones	steering cones

beam pattern	model the beam pattern with help of polar plots (maximum response axes): transmitting , receiving , product of both (frequency 95kHz, PS beam steering 33º, FA beam steering 11º); interactive changes of frequency; along and across arrays; beam steering parameters, to use vernier spacing Illuminated Plate and Bottom Detection Window must be open. The longer array length, the narrower beam. Fully functionality was never brought up (across arrays, sound speed).
Shading Opts	leftover from previous 2D versions of this tool, does not work in this version
Circ. Plane	circular plane, single beam echosounder (slow change arrow length)
Cont. Line	continuous line
Disc. Line	discontinuous line, proper steering
Multibeam	multibeam pattern
mat.props.	material surface property from OpenGL (beam pattern, cones: diffuse, ambient, specular, shiny) note: does not work with plate (seabed is illuminated acoustically)
Light 1	instead of this button, use key 1
Light 2	instead of this button, use key 2
Rot.Seq.	rotation sequence selection; "Do you pitch around original axis or around axis of actual ship?"
YPR Tate Bryant	Yaw, Pitch, Roll, this order is an official order used by ships and all world airplanes; roll around the axis which was heading and pitch changed
YPRo HIPPY	Yaw, Pitch, Roll; roll around unpitched axis (Hanewell)
YRP	Yaw, Roll, Pitch
PRY	Pitch, Roll, Yaw
RPY	Roll, Pitch, Yaw
RYP	Roll, Yaw, Pitch
PYR	Pitch, Yaw, Roll
sonar model	sonar model select (mount roll and pitch tilt, mock beam spacing) This assumes on the command line you have listed "-bf xxx -bf yyyyy -bf zzzz " etc... This means you are pre-loading a "beam footprint" model. Example exist for various common sonars - they specify EA or EDBS beam spacing, beam size, spacing and ping sequence.
Select	beam footprint model selector
make mockup	It allows you to make a crude beam model using the slider bars. This actually implements it.
plt.sel.	select imported plate
cone in cone	tests non orthogonal cone alghorithms (! do not steer so that they do not intersect - it crashes the program !); translations and rotations: TX and RC roll, pitch and yaw, TX orientations and RC deltas in RPY directions
CONES	display cones
PLANE	display horizontal plane of transducer
JOHN	This is historic - these are two versions of code to implement the rotations and calculating the final beam vector.
JONB	this one does NOT exactly match the intersection of the two cones - i.e. not conforming to openGl math.
----	nothing
debug	nothing
currents	ADCP currents widget An only partly finished widget - have to load a vertical profile of current vectors using the "-currents" command line option. It reads it a sequence of ADCP vertical velocity profiles and you can then make an animation showing the ADCP current field evolving over time.
Temp	- not implemented
Salinity	- not implemented
Backscatter	- not implemented
Velocities	- not implemented
LBL	Long Baseline Transponder Array Control A widget to display LBL geometry can change the location (and presence) of each one of the LBL transponders as well as the location and depth of the target. Then ranges from each target are calculated and the intersection of each sphere is displayed. SLIDER BARS --- target x-y-z is movable click on the list of each transponder to select - then use X-Y-Z slider bar to move. space bar on each transponder turns it on and off.
spheres	toggle spheres
rays	toggle rays to the target
P.depth	This shows how a pressure gauge on the tracked hydrophone will solve for the depth - often LBL geometry is so flat it reduces to a 2D solution and you can't solve for the vertical very well.
target	toggle target
cone steer	cone steering demonstrations This widget shows how active motion stabilisation is implemented. ! Have to use an ASCII motion time series ! >synSwath -ts gggggg get one from here: ggggg SLIDER BARS --- Compensation angle , when pitch stabilising is the elevation angle when the pitch stabilisation is perfect. Default is at Zero, ie. all other beams are OVER pitch compensated. Bellow 35-40° the nadir will be under compensated, 35-40° perfect, and > 35-40° is over compensated. Max Steering Angle - for yaw or pitch stabilsation. This is the max steering that will be implelented on the transmitter. For demo purposes it is good to increase this form the default 15 to ~ 70°. Angular Sector - starts off as a 120° sector (+/- 60°). User can change it to whatever she/he likes. Also need to have the Animation widget up where you choose to turn on/off Yaw/Pitch/Roll stabilisation.
Single 1 Sector	Default - only 1 transmit sector with only one steering angle allowed.
Single 3 Sector	e.g. shallow EM300 / EM120 or EM710
Twin 2 Sector	e.g. Hydrosweep MD
Twin 4 Sector	what Fansweep could do BUT IT DOESN'T
Single 9 Sector	e.g. deep EM300/EM120 (used in Labrador Sea)
draw history	together with Go icon in Animation window
Thomson - Sim	Cycles through - Single swath - Thomson SeaFalcon (7 swaths shown but only really 5) - then 2 swath EM710 and finally 8 sectors of the new Fansweep 30. / / /
MRU demo	Seatex MRU-6 (serial port connection) sensor outputs to the computer screen.
Objects	object selection menu (the same as keyboard S). Hitting the point in the middle will return object to default size. Hold left mouse button to roll, pitch etc. the object and to move green axis.
Plate	rotate, roll, pitch, expand, vertically exaggerate (sun illuminate with +- buttons), middle mouse click, arrows buttons when you are on the window with mouse, + - keys serve as a vertical distance from the ship
Phase	phase transmit - receive product
Int.	intensity transmit - receive product
Time	!!WRONG!! !!WRONG!! Time Off ! works just together with Bottom Detection Window !
Centre
Edge
Select	default closes Plate Window
+ / - bt.	bottom type; first minus / second minus / plus
+ / - sun	sun intensity
Bot.Det.	interactive bottom detection window ; horizontal axis is TIME; lowest part in green displays INTENSITY (time of bottom detection) with BINS in vertical axis (up and down arrows for scaling); middle part in red is PHASE with vertical axis 0 - 360º; upper part of window serves as a display of ZOOMed intensity) which works only after Illumination, or with GO button in Animation menu, note: assumption is an imported plate (see bellow)
Ang.Resp.	if you keep mouse arrow on the "Noise On", you can increase or decrease noise amount with up and down arrow keys corrected for spherical spreading
AR	Angular Response; AR Off is radiated intensity (much smoother!), no graph in AR Window; -50 dB / -80 dB
BT
Shd.	shading turns yellow when unimagable
Noise	Noise On / Noise Off
Multiples
Rayleigh
Animation	time series of roll, pitch, heave, heading and time; faster when beam pattern off; !do not animate with plate!
calc.
roll stab	unstabilized and stabilized roll
pitch stab	unstabilized pitch ; mechanically better than electronically
Gyro stab	stabilize Gyroscop
Dump INSON
--GO--	START button for recording; number of samples saved
Record	automatic recording of .ppm images in intervals of seconds
Mpitch stab	stabilize pitch movement if there is some waving
ADCP	Acoustic Doppler Current Profiler A widget to explain the workings of an ADCP - not entirely finished.
beam patterns	display beams of ADCP transducer
beam vectors
currents	adds paralell current layers to the water column
bottom mask
Ref. Frame	display reference frame of used object; keyboard shortcut: SPACEBAR note: After klicking sensor play with its layout (pressure gauge, subbotom profiler, sidescan, GPS anntenna).
levers	Levers On / Levers Off
transparency	Transparency On / Transparency Off
default ship	display ship
ROV	display ROV
AUV	display AUV
sensor coords	display sensor coordinates