Specifications
Sonartheory
Sonartheory
Thischapterexplainssomeofthebasictheoryrelatedtosettings,errorsourcesand
noiseconditions.
Topics
•Parametersonpage101
•Noiseandreverberationonpage106
•Layersanddeectionsonpage109
Parameters
Asonarwilltransmitasoundwaveintothewateraroundthevessel.Whenthissound
wavehitssh,bottom,orotherobjectsinthewater,apartofthesoundwillbereturned
asechoes.Theseechoesarecollectedbythesonar,interpretedbythesonarcomputers,
andpresentedonthedisplay.
Themostimportantinterpretationishoweverlefttoyou,anditmayoftenbedifcultto
distinguishtheechoesandidentifythetargets.Inordertohelpyouwiththis,theSH90
sonarprovidesnumerousadvancedlterandgainfunctions.Y oucanalsotiltthesonar
beamverticallyinordertoachieveanoptimumresult,andyoucanusethevertical
slicetoview“across”thewatercolumn.
Thissectionprovidesyouwithsomebasictheoryaboutsomeofthekeyparameters
thatareavailable.
Topics
•WhatisTVG?onpage102
•WhatisAGC?onpage102
•WhatisthePPFilter?onpage103
•Aboutpulseformandlengthonpage103
•Aboutbeamwidthsonpage104
•AboutGainonpage104
•WhatisRCG?onpage105
•Abouttiltonpage105
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