Icom MarineComander MXS-5000 Instruction Manual

Icom MarineComander MXS-5000 Instruction Manual Manual pdf 112 page image

3-403 RADAR OPERATIOND Blind and Shadow sectorsBlind or Shadow sectors may exist because of ob-structions such as masts, derricks or stacks. An ob-struction may throw either a complete or partialshadow as shown in the diagram below. If a target isin a shadow sector, target echoes may not appear onthe screen.When tall and massive targets such as a large islandare located at close range also shadowed withoutproducing any echoes. This phenomenon is calledblind sector. It is very important to know the bearingsand widths of all shadow sectors caused by your ownship’s obstructions.D Target resolutionTarget resolution is determined by the horizontalbeam width and transmit pulse width. Sometimes it isdifficult to detect two targets which are separated byshort distances or which are in the same direction.• Distance resolutionWhen two targets are separated by more than thepulse width, they appear as two echoes.When two targets are not separated by more thanthe pulse width, they appear as 1 echo.TransmitpulseEchoesTarget 1 Target 2Target 2Target 1• Direction resolutionWhen two targets are separated by more than thehorizontal beam width, they appear as two echoes.When two targets are not separated by more thanthe horizontal beam width, they appear as oneecho.ScannerTarget 2Target 1Target 1, 2Mast orsimilarobstructionShadow sector Blind sectorOwn ship LargeislandSmallislandTarget 2Target 1ScannerTarget 2Target 1TransmitpulseEchoTarget 1,2Target 1, 2