Simrad ES80 - Page 304

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SampleInterval
TheinformationfromeachES80transducerisacontinuousowofanalogue
data.Insignalprocessing,samplingisthereductionofthiscontinuoussignaltoa
discretesignal.Weconvertasoundwave(whichisananaloguecontinuous-time
signal)toasequenceofsamples(whichisadiscrete-timesignal).Thesamplerate
istheaveragenumberofsamplesobtainedinonesecond.Thesampleintervalis
1/sampleratetoallowreadoutintime(normallymilliseconds).
Start/EndFrequency
ThissettingiscontrolledintheNormalOperationdialogbox.TheStartFrequency
andEndFrequencyparametersareusedtosetupafrequencysweep("chirp").If
theparametersforstartandendfrequenciesareunavailable,thetransducerused
ontherelevantchanneldoesnotsupportwidebandtransmissions.Inordertouse
thefrequencysweep("chirp")functionality,youmustusefrequencymodulated
(FM)pulses.
Power
ThissettingiscontrolledintheNormalOperationdialogbox.ThePowerparameter
intheNormalOperationdialogboxdisplaysthetransmitter'soutputpower
measuredinWatts.Youcanchangetheoutputpowermanually.Outputpoweris
limitedeithertothemaximumratingofthetransducer,orthemaximumratingof
thetransmitter,whicheveristhesmallest
.
Slope
TheSlopevalueidentieshowfasttheoutputpowerineachtransmission("ping")
goesfrom0tomaximum.Thevalue(in%)indicatestheamountofthepulse
durationthatisspentduringthisincrease.Forexample,iftheSlopevalueis
50%,itmeansthathalfthedurationofthe"ping"isspentbuildingupthepower
tomaximum.
TheSlopeisalsocommonlyknownasRamping.IntheES80,thissettingis
automatic,whileonscienticechosoundersyoucanadjustitmanually.
PingRate
Thephrasepingrateisusedtodescribetheparameterthatcontrolshowoftenthe
ES80canorshalltransmitacousticenergy(a"ping")intothewater.Thepingrate
isnormallylimitedbythemaximumrangesettings.Itwillalsobedependanton
hardwareissues.Thismaybe,forexample,howfastyourProcessorUnitcan
handletheinformationfromeachping,howfastyoursystemcommunicateswith
externalperipherals,orhowlongtimethesystemusestosavedata.
Thepinginterval(1/pingrepetitionfrequency(PRF))isthepingratemeasuredin
timebetweeneachtransmission.
ThisinformationisalsofoundintheBITE(Built-InTestEquipment)dialogbox.
YouopentheBITEdialogboxfromtheSetupmenu.
SimradES80ReferenceManual