Simrad ES80 - What Is Sampling

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Whatissampling?
TheinformationfromeachES80transducerisacontinuousowofanaloguedata.In
signalprocessing,samplingisthereductionofthiscontinuoussignaltoadiscretesignal.
AcommonexampleisexactlywhatwedointheES80.Weconvertasoundwave
(whichisananaloguecontinuous-timesignal)toasequenceofsamples(whichis
adiscrete-timesignal).
Adiscrete(ordiscrete-time)signalisasequenceofdatacapsules.Thistypicallyasignal
thathasbeensampledfromacontinuous-timesignal.
Unlikeacontinuoussignal,adiscretesignalisnotafunctionofatimeargument,but
asequenceofquantities,afunctionoveradomainofdiscreteintegers.Eachvaluein
thesequenceiscalledasample.
Inthiscoordinatesystem,
theY-axisisvoltage(or
“volume”)andtheX-axis
istime.
AThisisacontinuous
owofdata,an
analoguesignal,for
exampleanecho.
BThislineidenties
thesamplesthatthesystemisextractingfromtheanaloguesignal.Eachsample
isidentiedwiththetimeitwastaken.Itwillcontainthevalueoftheanalogue
signalatthattime.
CThedistancebetweeneachverticallineisthetimebetweeneachsample.This
timeisidentiedasthesamplingrate.
Usingthistechnique,theanaloguesignalisconvertedtoastreamofdiscretesignals.
Conceptdescriptions