Simrad ES80 - Defining the Frequency Sweep (Chirp) Within each Transmission

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ForCWtransmissions:
•Longpulsesprovideslongerdetectionrange.TheymaketheES80lesssensitivefor
noise,butofferlowerrangeresolution.
•Shortpulsesprovidesshorterdetectionrange.TheymaketheES80moresensitivefor
noise,butofferhigherrangeresolution.
ForFMtransmissions:
•Longpulsesprovidelongerdetectionrange,butofferlowerrangeresolution.
•Shortpulsesprovideshorterdetectionrange,theymaketheES80moresensitivefor
noise,butofferhigherrangeresolution.
Tip
WhenyouselectAuto,theES80willautomaticallyselectthebestpulsedurationforthe
currentoperationalmode,depthandbottomconditions.Fornormaluse,werecommend
thatthepulsedurationissettoAuto.
Procedure
1OpentheOperationmenu.
2SelectNormalOperation.
ObservethattheNormalOperationdialogboxopens.
3Fortherelevantchannel,setPulseDurationtoyourchosenvalue.
4SelectOKtosavetheselectedsettingandclosethedialogbox.
Deningthefrequencysweep(chirp)withineach
transmission
TheES80supportswidebandtransmissionsusingfrequencysweeps.Thisisoften
referredtoas"chirp",andmeansthatthetransmissionfrequencychangesfroma"start"
frequencytoan"end"frequencywithinthetransmission.Inordertousethefrequency
sweep("chirp")functionality,youmustusefrequencymodulated(FM)pulses.Youmust
alsouseawidebandtransducerthatsupportsthecompletefrequencyrange.
Context
TheStartFrequencyandEndFrequencyparametersareusedtosetupafrequencysweep
("chirp").Iftheparametersforstartandendfrequenciesareunavailable,thetransducer
usedontherelevantchanneldoesnotsupportwidebandtransmissions.Inordertousethe
frequencysweep("chirp")functionality,youmustusefrequencymodulated(FM)pulses.
Operatingprocedures