Furuno GP-1650F, GP-1650DF Interpreting the Display, Zero line, Fish school echoes, Bottom echo

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2.15 Interpreting the Display

Zero line

The zero line (sometimes referred to as the transmission line) represents the transducer’s position, and moves off the screen when a deep phased range is used.

Zero line

Shift

Figure 2-31Zero line

Fish school echoes

Fish school echoes will generally be plotted between the zero line and the bottom. Usu- ally the fish school/fish echo is weaker than the bottom echo because its reflection prop- erty is much smaller compared to the bot- tom. The size of the fish school can be ascertained from the density of the display.

Bottom echo

Echoes from the bottom are normally the strongest and are displayed in reddish-brown color but the color and width will vary with bottom composition, water depth, frequency, sensitivity, etc.

In a comparatively shallow depth, a high gain setting will cause a second or sometimes a third or a fourth echo to be displayed at the same interval between them below the first echo trace. This is because the echo travels between the bottom and the surface twice or more in shallow depths.

The color of the bottom echo can be used to help determine the density of the bottom ma- terials (soft or hard). The harder the bottom, the wider the trace. If the gain is set to show only a single bottom echo on mud, a rocky bottom will show a second or third bottom return. The range should be chosen so the first and second bottom echoes are displayed when bottom hardness is being determined.

Intensity difference in water depth

Second bottom echo

Size of fish school

Small Large school school

Rock base

Mud and sand

Figure 2-32 Fish school echoes

Figure 2-33 Bottom echoes

2-11

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Contents Color DGPS/PLOTTER/SOUNDER Color GPS/PLOTTER/SOUNDER 199 Do not open the equipment About the TFT LCDDo not disassemble or modify the equipment Do not operate the equipment with wet handsTable of Contents Sounder Setup Options SpecificationsDeclaration of Conformity IiiForeword FeaturesWord to GP-1650DF/1650F Owners Display Unit System ConfigurationThis page is intentionally left blank Display Unit Controls Operational OverviewTurning the Power On/Off Inserting Mini Chart CardTurning the power off Display abbreviationsPlotter Displays Adjusting Tone and BrillianceSelecting a display Menu Operation, Soft Keys Sounder DisplaysPlotter/Sounder Display Normal Sounder DisplayDemonstration Display 10 Demo setting screenThis page is intentionally left blank Principle of Operation Video Sounder OperationNormal sounder display indications, markers Sounder Display DescriptionKHz picture Bottom-zoom display Selecting sounder display modeMarker zoom display Bottom-lock displayDual-frequency Display Plotter/Sounder DisplayScope display EnterManual Sounder Operation Automatic Sounder OperationMeasuring Depth Adjusting the gainSelecting display range Range shiftingSuppressing Low Level Noise Suppressing InterferenceWhite Marker Erasing Weak EchoesSelecting Background and Echo Colors Selecting Picture Advance SpeedBackground and echo colors Alarms Zero line Interpreting the DisplayFish school echoes Bottom echo34 Surface noise/aeration Surface noise/AerationPresentation Modes Plotter DisplaysNorth-up Course-upMini Chart Cards Selecting Chart Scale/RangeCursor Shifting the DisplayRemarks on chart display Indices and chart enlargementChart symbols Furuno mini chart cardComparison of Furuno and Nav-Charts chart cards Port service icons Nav-Charts cardsAid to navigation data Enlarging an indication Navigation Data DisplayGPS satellite monitor display Steering Display How to read the compass displayBeacon information display Setting the range of the XTE scale How to read the XTE scaleHighway Display Fifure 3-16 Display setup1 menu Changing Operation ModeNavigation Trip Distance FishingDisplaying Track TrackTracking Changing Track Color Stopping/Restarting Plotting of TrackTrack Plotting Method, Interval Track plotting methodTrack plotting interval Changing Track Memory CapacityTrack Memory Erasing All Track Entering Marks MarkPlotter display Video sounder display Changing Mark AttributesVideo sounder display Tions Changing Mark SizeSmall Displaying Track and Mark Points Erasing MarksErasing individual marks/lines Erasing whole marks/linesEntering Waypoints WaypointsEntering waypoints at own ship’s position Entering waypoints at MOB positionChanging the shape and color of waypoint mark Waypoint menuEntering waypoints by range and bearing Changing waypoint name, comment, proximity alarm radiusEntering waypoints by latitude and longitude position Changing waypoint positionChanging Waypoint Data Erasing Individual WaypointsErasing waypoints through the waypoint list Erasing waypoints by the cursorChanging Waypoint Position on the Plotter Display Waypoint Mark SizeSearching Waypoints This page is intentionally left blank Entering Routes RoutesEntering routes through the route list AbcdefInserting, Removing Waypoints Connecting RoutesEntering routes by the cursor Inserting waypoints through the route listRemoving waypoints from routes Inserting waypoints on the plotter displayAlph List WPTRemoving route waypoints from the plotter display Creating Track-based RoutesSave icon appearance On the plotter display Erasing RoutesThis page is intentionally left blank Navigating to Quick Points NavigationSelecting quick point entry method Navigating to a single quick pointNavigating to Waypoints waypoint list Navigating to Ports, Port ServicesNavigate route waypoints in reverse order Following a RouteNavigate directly to a route waypoint Navigate along specific leg of routeSwitching waypoints Setting speed for ETA calculationRestarting navigation Cancelling Navigation This page is intentionally left blank Audio Alarm On/Off Plotter AlarmsArrival Alarm IntroductionXTE Cross Track Error Alarm Anchor Watch AlarmProximity Alarm Speed AlarmAlarm messages Alarm InformationAlarm messages and their meanings Formatting Memory Cards Saving Data to Memory Card10-1 Saving dataLoading Data from Memory Card Error message10-2 Data overwrite10-3 ConfigurationTrack Waypoint/routeThis page is intentionally left blank Chart Offset menu Chart Setup Options menuCustomizing Your Unit 11-1Chart details menu description Chart Details menuDisplay Options menu 11-211-3 Display setup1 menu description11-4 Display SETUP2 menu description11.3 GPS/DGPS/TD Options menu GPS Setup Options menu description11-5 Dgps Setup Options Dgps Setup Options menu11-6 TD Setup TD Setup menu11-7 Displaying Loran C TDsSounder Setup Options menu description Sounder Setup Options menuRange Setup soft key 11-8System Setup menu description System Setup soft key11-9 Echo Offset 200kHz, Echo Offset 50kHzSetup Nmea Port 1 menu description Configuration menuSetup NMEA/DGPS Port 2 menu description 11-10UPLOAD/DOWNLOAD Data menu 11-11XON/XOFF Download waypoint/route to PC22 Connection of GP-1650DF/GP-1650F to PC 11-12System menu 11-13System Menu description This page is intentionally left blank Using C-MAP NT Model Example of caution area window 12-2Objects window 12-313 Plotter display 12-4Setting Chart Setup Options 20 Depth Info display 12-621 Memory, I/O test results 12-7This page is intentionally left blank Maintenance Maintenance & TroubleshootingRecommended maintenance program 13-1Simple Troubleshooting Replacement of Fuse, BatterySimple troubleshooting plotter 13-2Simple troubleshooting sounder Error MessagesError messages 13-313-4 Diagnostic TestsMemory, I/O port test TestKeyboard test 13-5Display test 13-6 Clearing MemoriesMenu Tree Furuno chartSounder Setup Options Audio Alarm ON, OFF Loran C Chains Decca Chains World Time Geodetic Chart List GPS Receiver GeneralDisplay Section PlotterCoating Color Index-1 IndexIndex-2 Index-3