4381291/D
Transmittingwithxed-timeintervals...................................................................54
Adjustingtheoutputpowertomatchvaryingconditions......................................55
Selectingthebestoperatingfrequency...................................................................56
Controllingthegainandrangesettings...........................................................................58
Adjustingthegain(echosensitivity)......................................................................58
AdjustingtheTVG(TimeV ariableGain)setting..................................................60
Adjustingthesonarrange.......................................................................................60
Expandingtherangewithinthesonarview...........................................................62
Adjustingtheintensityoftheechopresentations...................................................63
Changingthetilt.....................................................................................................63
Adjustingthebearing.............................................................................................65
Usingthemarkersandtrackingfeatures..........................................................................68
Startingapositiontrack..........................................................................................68
Startingatargettrack..............................................................................................69
Placinganewmarker.............................................................................................70
Deletingamarker...................................................................................................71
Measuringthesizeofaschoolrelativetothepurseseine.....................................72
Usingvisualaidsduringthepurseseinecatchphase.............................................72
Selectingageographicalareaforaccuratetargettracking.....................................74
Deningthephysicalsizeofthetrackingarea.......................................................75
Choosingtheshinggearinuse.............................................................................76
Changingtheshinggearpropertiestomatchyourownequipment.....................77
Improvingtherecognitionofshandschoolsusingreceiverlters...............................78
AboutthereceiverltersequenceintheSU90system..........................................78
ReducingnoiseandreverberationwiththeAGC(AutomaticGainControl)
function..............................................................................................................79
ReducingpropellernoiseandinterferencewiththeNoiseFilter...........................80
ReducingbottomandsurfacereverberationwiththeRCG(Reverberation
ControlledGain)function..................................................................................81
ReducingnoiseandfalseechoeswiththePing-PingFilter...................................83
Reducingthestrongbottomechotoseeshclosetotheseabed...........................84
Adjustingtheintensityoftheechopresentations...................................................84
Recordingandreplayingechodata..................................................................................86
Deningtheleandfoldersettingsfordatarecording..........................................86
Recordingechodata...............................................................................................87
Accessingtheechodatalestodelete,moveorcopythem..................................88
SelectingReplaymode...........................................................................................89
Choosingwhichechodatale(s)toreplay............................................................90
Settinguppresentationmodesandviews........................................................................92
Movingaviewtoanotherdisplay..........................................................................92
SimradSU90
