Virtual image, Shadow sectors | Furuno FR-8122, FR-8252, FR-8062

2. RADAR OBSERVATION

2.2.3Virtual image

A relatively large target close to your ship may be represented at two positions on the screen. One of them is the true echo directly reflected by the target and the other is a false echo which is caused by the mirror effect of a large object on or close to your ship as shown in the figure below. If your ship comes close to a large metal bridge, for example, such a false echo may temporarily be seen on the screen.

Target ship

Own ship

True echo

False

Mirror imageecho of target ship

Virtual image

2.2.4Shadow sector

Funnels, stacks, masts, or derricks in the path of the antenna block the radar beam. If the angle subtended at the antenna is more than a few degrees, a non-detecting sector may be produced. Within this sector targets can not be detected.

Radar antenna

Radar mast

Shadow sector

Shadow sectors

2-4

Image 80

Furuno FR-8122, FR-8252, FR-8062 manual Virtual image, Shadow sectors

Contents

FR-8062 FR-8122 Model FR-8252 00015331616 How to discard this product How to discard a used battery GeneralEuropean Union USA Safety Instructions Iii Electrical Shock Hazard TFT LCD Table of Contents Table of Contents Vii Radar Observation Viii SP-1IN-1 Features ForewordWord to the Owner of the FR-8xx2 Marine Radar Model, output, range, antenna Description Specification River Sea Radar Specifications and Function AvailabilitySpecification and function availability System Configuration FR-8252 Xii FR-8122, FR-8062 Display unit Operational OverviewControls Remote controller Remote controller Turning the Radar On/Off, Transmitting Quick startStart-up screen FR-8252 Display Indications Watchman Adjusting Display Brilliance, Panel Dimmer Menu OverviewBrill/Panel dialog box Menu Menu description System Tuning Tuning optionsTuning indicator Tuning Description of presentation modes Choosing presentation modePresentation Modes North-up mode True motion mode Automatic resetting of own ship marker in true motion mode Choosing a Range Scale Choosing a Pulse Length Echo Adjusting the Gain sensitivity Choosing gain adjustment methodSetting automatic gain level Manual gain adjustment Choosing sea clutter adjustment method Setting automatic sea clutter suppression levelSEA indicator Suppressing Sea Clutter Manual sea clutter adjustment Choosing rain clutter adjustment methodRain indicator Suppressing Rain Clutter Appearance of rain clutter Setting automatic rain clutter suppression levelManual rain clutter adjustment Automatic Suppression of Sea and Rain Clutters Cursor data CursorCursor data Interference Rejector Interference Measuring the Range to a Target Measuring range by the variable range marker VRM Choosing VRM unit Turning Range Rings On/Off, Adjusting Range Ring Brilliance Brill/Color Measuring the bearing with an EBL How to measure the bearing to a target with the EBLMeasuring the Bearing to a Target Measuring the Range and Bearing Between Two Targets EBL reference Target Alarm Setting a target alarmSilencing the audio alarm How to set a target alarm zone Choosing alarm type Temporarily deactivating a target alarmDeactivating a target alarm Out alarms Choosing target strength which triggers target alarm Off Centering the DisplayAutomatic off center Choosing speed to use How to zoom ZoomManual off center Activating automatic off center Zoom mode Relative or true zoom modeTarget zoom mode Key to erase the message Stretch in range direction Stretch in bearing direction Echo stretch settingsEcho Stretch Detection can result Is automatically disabledEcho Averaging Tively, execute All Cancel on the Trails menu Target TrailsStarting, stopping trails Trail indications Trail mode Target Trails Trail level Trail gradationTrail color Trail copy Narrow trailsOwn ship trail How trail copy works Trail length Restart feature Trail copy feature ActionRestarting trails Adjusting parallel index line orientation and interval Parallel Index LinesTurning parallel index lines on or off Parallel index lines Outputting Target Position, Inscribing Origin Mark Parallel index lines modeTLL key mode Custom Setup Origin mark modeAbout custom setup Temporarily Hiding the Heading Line Menu item Available settings Description of custom setup itemsDescription of custom setup items Setting custom setups Sample custom setupsMenu item Application Custom Programming Function Keys F1 and F2 keys Function key operationChanging function key program Function list How 2nd trace echoes are produced Noise RejectorSuppressing Second-trace Echoes Watchman How watchman works Preset color schemes Color SchemesUser color scheme Display item, color scheme and color Navigation data display at standby Navigation DataNavigation data during standby Depth and water temperature graphs Navigation data at the bottom of the screenWind graph Navigation data Display curve Characteristics CurveDynamic Range Antenna Speed Waypoint Marker Waypoint mark List of alarm messages Alarm Message DisplayList of alarm messages Alarm category Alarm name AIS alarm AIS system Echo Area Customizing Initial Menu Opening the Initial menuDescription of Initial sub menu Initial menu Available ranges Sector Blank Sector Blank Appearance of sector blank GPS buoy symbols GPS BuoyDisplaying GPS buoys GPS buoy menu Choosing symbol color History display Erasing all GPS buoys symbols Erasing GPS buoy symbolsErasing individual GPS buoy symbols Remote Display Unavailable menu itemsMenu items not available with the remote display Display appearance Items unavailable with Function key F1, F2 Total TX time indication This page intentionally left blank Radar Observation GeneralMinimum and maximum ranges Minimum range Radar resolution Bearing resolutionRange resolution Bearing accuracy False Echoes Multiple echoesSidelobe echoes Sidelobe echoes Virtual image Shadow sectorVirtual image Shadow sectors Appearance of Sart echo Sart Search and Rescue TransponderSart description Sart range errors General remarks on receiving SartRadar bandwidth Radar side lobes Usage Precautions ARP Operation Controls for Use with ARP ARP Display On/OffARP menu ARP Acquiring and Tracking Targets Manual acquisitionAutomatic acquisition ARP target mark Terminating tracking of all targets Terminating Tracking of ARP TargetsTerminating tracking of selected targets What is a vector? Vector AttributesVector time, vector reference Vector History Display target past position Target movement and history display ARP Target Data ARP target data CPA/TCPA Alarm Proximity Alarm Canceling a lost targetLost Target Lost target mark Symbol Color AIS Operation Controls for Use with AISTurning the AIS Display On or Off AIS menu AIS Symbols Is changed while using the head-up modeActivating, Sleeping Targets Appearance of an activated target Displaying AIS Target Data AIS data Display Range Sorting Targets Displaying Targets Within a Specific Sector Number of Targets to Display Vector Attributes History Display target past position 12 CPA/TCPA Alarm Proximity Alarm Lost target symbol Removing all lost AIS targets from the displayShip speed and reporting interval Ship speed Reporting interval GPS Operation Navigator TypeGPS menu GPS Waas Setup Datum Satellite Monitor Satellite monitor Weather Information Type 16 message GPS Sensor Installation Position Offset Cold Start To perform cold start, do the following Maintenance & Troubleshooting Do not open the equipment Interval Check point Remedy Preventive MaintenanceMaintenance Fuse Replacement Magnetron LifeLCD Backlight Life Unit and fuses Trackball Maintenance Display unit Simple Troubleshooting Simple troubleshootingBut Then STBY/TX key to Advanced-level Troubleshooting Advanced-level troubleshootingCessful, replacement of the keypad may Down to component level are not practical by users Problem Probable cause or Remedy Check points Factory Diagnostic TestFactory menu DIagnostics screen 㪇㪊㪌㪐㪉㪉㪐㪄㪯㪯㪅㪯㪯 LCD test screens LCD TestGPS Test Choices for Function 1 Setup, Function 2 Setup Appendix Nm for distance 0.1 nm or greater ARP*1 AIS*2 GPS*1 Furuno Specifications of Marine Radar FR-8062/FR-8122/FR-8252 Furuno Coating Color FR-8xx2 Series E3539S01G Index AIS IN-2 VRM Declaration of Conformity