. OPERATIONAL OVERVIEW 1.20 The Settings Menu The [Settings] button gives you access to the user profiles and the [Settings] menu. The [Settings] menu has facilities for screenshot management, file management, diagnostic tests and customizing. See chapter 22. [Settings] button 1.21 User Profiles for Radar, Chart Radar The [Settings] button lets you store ten sets of custom settings and color settings (echoes, TT and AIS symbols and echo trails).
1. OPERATIONAL OVERVIEW 1.21.4 How to restore a profile to the default settings 1. Click [ ] on the Status bar then click [Manage Profile]. 2. Select a profile number from the “Profile” drop-down list. 3. Click [Restore Default Settings]. The confirmation message "Attention: This profile will be restored to the default. Do you wish to continue?" appears. 4. Click [Yes]. Note: This setting for the default is available when selecting a profile to activate next time (see paragraph 1.21.3). 1.21.
1. OPERATIONAL OVERVIEW Items AIS CPA Operating mode MAP (Radar map) Route Alert Antenna connection status RANGE RING PI LINE SPD (Own Ship Sensor Setting) 1.
1. OPERATIONAL OVERVIEW The information shown in the following illustration may be different from those on your system. XXXXXXXXXXXXXXXXXXXXXXXXXXXX [Version] tab Startup Time : 06 Jan 2014 09:23:20 Equipment ID : ecdis,radar Function : [System 1] tab 1.23 [System 2] tab Tips (operational guidance) This chart radar provides operational tips for the display area, InstantAccess bar and Mark box. To get a tip, simply put the cursor on the object.
2. RADAR, CHART RADAR OPERATION 2.1 How to Transmit After the power is turned on and the magnetron has warmed*, "ST-BY" appears at the screen center, meaning the radar is ready to transmit radar pulses. You can transmit by pushing the STBY/TX key on the Control Unit, or clicking the [STBY TX] button on the Status bar. [STBY TX] button *: The solid state radar does not have a magnetron, therefore it has no warming period. The radar is initially set to previously used range and pulse length.
2. RADAR, CHART RADAR OPERATION Manual tuning To tune the radar, start by setting the brilliance to a comfortable level, adjusting the gain until the background speckle just disappears, and selecting the 48 NM range. Then, do the following: 1. Select a weak contact somewhere near the edge of the screen and concentrate on that, while adjusting the gain control in small steps - allowing at least two seconds between each step - until the chosen contact is as big, bright and consistent as possible. 2.
2. RADAR, CHART RADAR OPERATION 2.3.2 How to change the pulse length 1. Click the [Pulse] button at the top of the InstantAccess bar. 2. Click a pulse length. 2.4 How to Adjust the Sensitivity The GAIN control (or [Gain] button) adjusts the sensitivity of the receiver. The proper setting is such that the background noise is just visible on the screen. If you set up for too little sensitivity, weak echoes may be missed.
2. RADAR, CHART RADAR OPERATION 2.5.1 How to reduce sea clutter automatically Auto A/C SEA allows for fine-tuning of the A/C SEA circuit, within ±20 dB. Lower the auto A/C SEA level because the average value of the original input echo is low in areas where there are no see surface reflections. For example, when the ship is alongside a quay and the radar picture shows echoes from both land and sea, you can observe the size of echoes because the STC curve is different depending size of echoes.
2. RADAR, CHART RADAR OPERATION 2.6 How to Suppress Rain Clutter The vertical beam width of the antenna is designed to see surface targets even when the ship is rolling. However, by this design the unit will also detect rain clutter (rain, snow, or hail) in the same manner as normal targets. The A/C RAIN control adjusts the receiver sensitivity as the A/C SEA control does but rather in a longer time period (longer range). The higher the setting, the greater the anti-clutter effect.
2. RADAR, CHART RADAR OPERATION 2.6.2 How to reduce rain clutter manually Control Unit: Push the A/C RAIN control to display [MAN] on the RAIN mode indication on the Status bar. While watching the radar picture, adjust the A/C RAIN control to reduce the clutter. Trackball module: Click the RAIN mode indication on the Status bar to show [MAN]. For coarse adjustment, put the cursor within the slider bar area then push the left button.
2. RADAR, CHART RADAR OPERATION 2.7 Interference Rejector Mutual radar interference may occur in the vicinity of another shipborne radar operating in the same frequency band. It is seen on the screen as a number of bright spikes either in irregular patterns or in the form of usually curved spoke-like dotted lines extending from the center to the edge of the picture. Activating the interference rejector circuit can reduce this type of interference.
2. RADAR, CHART RADAR OPERATION 2.9 Echo Averaging The echo averaging feature, which requires heading, position and speed data, effectively reduces sea clutter. Echoes received from stable targets such as ships appear on the screen at almost the same position every rotation of the antenna. On the other hand, unstable echoes such as sea clutter appear at random positions. To distinguish real target echoes from sea clutter, echoes are averaged over successive picture frames.
2. RADAR, CHART RADAR OPERATION 2.10 Automatic Clutter Elimination (ACE) Function This radar has the Automatic Clutter Elimination (ACE) function. This function detects sea and rain clutter from received echoes’ range and bearing trend and automatically reduces sea and rain clutter according to the Automatic Clutter Elimination (ACE) threshold setting. Note: Use this function with caution. Weak target echoes may disappear from the screen. 2.10.
2. RADAR, CHART RADAR OPERATION 2.10.3 Automatic Clutter Elimination (ACE) menu Open the menu then select the [ECHO] and [ACE] menus to show the [ACE] menu. • [ADJUST]: No use. • [SIGNAL ENHANCEMENT]: Set the level for the high sensitivity mode (see paragraph 2.10.4). • [SUPPRESS SECTOR]: Set the angular range for suppression of false echoes (see paragraph 2.10.5). MENU ECHO ← ACE 1 ADJUST OFF / ON 2 SIGNAL ENHANCEMENT 2 3 SUPPRESS SECTOR 2.10.
2. RADAR, CHART RADAR OPERATION 2.11 Noise Rejector White noise may show itself on the screen as random "speckles" spread over the entire radar image. This equipment reduces the white noise then improves the on-screen S/N ratio by processing the weighted moving average filter for the received echoes in the range direction. Note: Use this function with caution. Weak target echoes may disappear from the screen or the range resolution may worsen. You can remove this noise as follows: 1.
2. RADAR, CHART RADAR OPERATION 2.12 Wiper The wiper feature automatically reduces the brilliance of unwanted weak echoes, such as noise, sea clutter and rain clutter, to clear the picture. There are two wiper settings, 1 and 2. The difference between 1 and 2 is that the brilliance is lowered more slowly in 2. To use the wiper feature, do the following: 1. Open the menu then select [1 ECHO]. 2. Select [8 WIPER] (B type) or [7 WIPER] (IMO and A types). 3. Select [OFF], [1] or [2] as appropriate. 4.
2. RADAR, CHART RADAR OPERATION use the user-programmable presets ([CUSTOM1] or [CUSTOM2]) when frequent adjustment of the radar image is necessary. OCEAN CANAL BERTHING CONGESTION ROUGH SEA HARD RAIN CUSTOM1 CUSTOM2 INT REJECT 2 2 2 2 2 2 2 2 ECHO STRETCH 2 OFF OFF OFF OFF OFF OFF 2 ECHO AVERAGE 3 OFF OFF 2 2 OFF OFF 1 NOISE REJECT ON OFF OFF OFF OFF OFF OFF OFF AUTO SEA OFF* OFF* OFF* OFF* OFF* OFF* OFF* OFF* 0.75 NM M1* S2 S1 S2 S1 S2 S2 S2 1.
2. RADAR, CHART RADAR OPERATION 2.13.1 How to select a customized echo Click the [Customize Echo] button on the Status bar to select a customize echo option from the drop-down list. [Customize Echo] button Click to show drop-down list. 2.13.2 How to edit a customized echo You can edit a customized echo as below. 1. Select a customize echo option to edit (see paragraph 2.13.1). 2. Right-click the [Customize Echo] button on the Status bar then click [Customize Echo Menu]. 3.
2. RADAR, CHART RADAR OPERATION 5. Spin the scrollwheel to select 1, 2, 3 or 4 (Dynamic Range) or A, B, C (Curve) as appropriate then push the left button. Refer to the description and illustration below. CONTRAST C B A CONTRAST 4 3 2 1 1-4: Control dynamic range. 1 provides the widest dynamic range; 4 is the narrowest dynamic range. A: The mid-level in the curve is low, so this setting is suitable for suppressing rain clutter. B: Curve between A and C.
2. RADAR, CHART RADAR OPERATION 2.14 How to Suppress Second-trace Echoes In certain situations, echoes from very far distance targets may appear as false echoes (second-trace echoes) on the screen. This occurs when the return echo is received one transmission cycle later, or after a next radar pulse has been transmitted. Pulse interval Actual ranges Second-trace echo Measured ranges This equipment lengthens the pulse repetition period to reject the false echoes.
2. RADAR, CHART RADAR OPERATION Mode availability Presentation mode Course-up RM Head-up RM STAB Head-up RM North-up RM North-up TM Stern-up RM* Availability Radar Chart radar Yes Yes Yes No Yes No Yes Yes Yes Yes Yes No *: Not available with IMO or A type. 2.15.1 How to select a presentation mode How to select a presentation mode from the Control Unit Push the MODE key consecutively to select radar presentation mode desired. The Range/Presentation mode box shows the current presentation mode.
2. RADAR, CHART RADAR OPERATION 2.15.2 Description of presentation modes Head-up mode The head-up mode is a display in which the line connecting own ship and the top of the display indicates own ship's heading. North marker Heading line The target pips are painted at their measured distances and in their directions relative to own ship's heading. The short line on the bearing scale is the north marker, which indicates heading sensor north.
2. RADAR, CHART RADAR OPERATION Sensor Not Available" or "Gyro COM1 Error" (a number between 250-259 according to gyro no.) appears in the [Alert] box. Stern-up mode The stern-up mode is a display in which the line connecting own ship and the top of the display indicates own ship's stern. Heading line The target pips are painted at their measured distances and in their directions relative to own ship's stern. The short line on the bearing scale is the north marker, which indicates stern sensor north.
2. RADAR, CHART RADAR OPERATION 2.16 How to Select the Range Scale The selected range scale and range ring interval are shown at the top-left position on the screen. When a target of interest comes closer, reduce the range scale so that it appears in 50-90% of the display radius. Range ring interval Range scale 6 Range selection buttons Note: The IMO- and A-type radars do not have the 1 NM, 2 NM, 4 NM, 8 NM, 16 NM, 32 NM and 120 NM ranges.
2. RADAR, CHART RADAR OPERATION 2.17.1 How to measure the range by using a VRM There are two VRMs, No. 1 and No. 2, which appear as dashed rings so that you can distinguish them from the fixed range rings. The two VRMs can be distinguished from each other by the different lengths of their dashes; the dashes on the No. 2 VRM are longer.
2. RADAR, CHART RADAR OPERATION 2.17.2 How to set VRM attributes You can customize the VRMs to suit your needs. 1. Open the menu then select [3 NAV TOOL] and [2 EBL•VRM] (B type) or [2 EBL•VRM•CURSOR] (IMO and A types) to display the [EBL•VRM] menu ([EBL•VRM•CURSOR] menu for the IMO and A types). IMO- and A-type radars 2. For the B-type radar, select [3 VRM1] or [4 VRM2] as appropriate. Spin the scrollwheel to select desired unit then push the left button. B-type radar 3.
2. RADAR, CHART RADAR OPERATION 2.18 How to Measure the Bearing to a Target Use the Electronic Bearing Lines (EBLs) to take bearings of targets. There are two EBLs, No. 1 and No. 2. Each EBL is a straight dashed line extending from the own ship position up to the circumference of the radar picture. The two EBLs can be distinguished from each other by the different lengths of their dashes; the dashes on the No. 2 EBL are longer.
2. RADAR, CHART RADAR OPERATION 2.18.2 How to select bearing reference An EBL box has an "R" (relative) if the EBL bearing is relative to own ship's heading; "T" (true) if it is referenced to the north. True or relative indication is available regardless of presentation mode. To change the bearing reference, click the EBL reference indication to display R or T as appropriate. The bearing reference can also be selected on the [EBL•VRM] menu ([EBL•VRM•CURSOR] menu with the IMO- and A-type radars).
2. RADAR, CHART RADAR OPERATION How to assess risk of collision from the context-sensitive menu 1. Right-click the display area to show the context-sensitive menu. 2. Select [EBL Offset] and then [EBL 1] or [EBL 2]. 3. Put the cursor on a target that appears as a threat (A in the figure below). 4. Push the left button to shift the EBL origin to the cursor location. 5. Spin the scrollwheel or use the trackball to bisect the target at the new position (A').
2. RADAR, CHART RADAR OPERATION 2.20 How to Measure the Range and Bearing Between Two Targets How to measure the range and bearing between two targets from the Control Unit 1. Press the EBL 1 key to activate EBL1. 2. Operate the trackball to place the origin of the EBL 1 on a target of interest. 3. Press the EBL OFFSET key. 4. Operate the EBL rotary control to bisect the other target of interest. 5. Press the VRM 1 key to activate VRM 1. 6.
2. RADAR, CHART RADAR OPERATION 2.21 How to Off-center the Display Own ship position, or sweep origin, can be displaced to expand the view field without switching to a larger range scale. The sweep origin can be off-centered to the cursor position, but not more than 75% of the range in use; if the cursor is put beyond 75% of the range scale, the sweep origin will be off-centered to the point of 75% of the limit.
2. RADAR, CHART RADAR OPERATION 2.22 Target Trails The trails of the radar echoes of targets may be displayed in the form of synthetic afterglow. Target trails are selected either relative or true and may be sea or ground stabilized. True motion trails require a compass signal, and position and speed inputs. 2.22.1 Target trails-related indications Trail-related indications are located at the bottom-right position on the screen.
2. RADAR, CHART RADAR OPERATION 2.22.3 Trail time Trail time, the trail plotting interval, can be selected with the scrollwheel, left button or right button. The trail timer counts up the trail time and is erased once the terminal count is reached. For example, if the trail time is six minutes, the timer is erased when trails have been plotted six minutes. The maximum time of count up for continuous plotting is 29:59.
2. RADAR, CHART RADAR OPERATION 2.22.7 Target trail attributes on the TRAIL menu [TRAIL GRAD]: The afterglow of the target trails can be shown in a single tone or gradual shading. Monotone (SINGLE) Gradual shading (MULTI) [TRAIL COLOR]: The trail color can be selected from the colors shown in the left figure. This feature is not available with the IMO or A type. [TRAIL LEVEL]: The level (intensity) of the afterglow that extends from radar targets can be adjusted.
2. RADAR, CHART RADAR OPERATION 2.23.1 How to display, erase a PI line How to display, erase a PI line from the Control Unit Displaying a PI line: Press the INDEX LINE key until desired PI line no. appears. Erasing a PI line: Press the INDEX LINE key until desired PI line no. appears. Press and hold down the INDEX LINE key to erase the PI line. How to display, erase a PI line from the trackball module Click the PI line no. indication to select a PI line.
2. RADAR, CHART RADAR OPERATION 4. Select [REL] or [TRUE]. 5. Close the menu. 2.23.5 How to select the PI lines orientation 1. Open the menu. 2. Select [3 NAV TOOL] and [1 PI LINE] to show the [PI LINE] menu. 3. Select [3 PI LINE MODE]. 4. Select [PARALLEL] or [PERPENDICULAR]. [PARALLEL]: PI lines are displayed in parallel to your ship's heading when PI line angle is set to 0°. [PERPENDICULAR]: PI lines are displayed in perpendicular to your ship's heading when PI line angle is set to 0°. 5.
2. RADAR, CHART RADAR OPERATION 6. Set the length (setting range: 0.000 to 24.000 NM). Heading line Own ship position PI line Adjust the length forward a PI line. Adjust the length backward a PI line. 7. Close the menu. 2.24 Zoom The zoom function enlarges an area of interest in the information area (magnification range: 1.0, 1.5, 2.0, 2.5, 3.0; 2.0 is default). To use the zoom display, right-click the operational area to show the context-sensitive menu then select [Zoom Set].
2. RADAR, CHART RADAR OPERATION 2.25 Markers 2.25.1 Heading line The heading line indicates the ship's heading in all presentation modes. The heading line is a line from the own ship position to the outer edge of the radar display area and appears at zero degrees on the bearing scale in head-up mode. It changes its orientation in the north-up and true motion modes according to orientation.
2. RADAR, CHART RADAR OPERATION 2.25.5 Vectors You can show or hide the vector for own ship and reference targets, on the [NAV TOOL] menu. 4 VECTOR COLOR GRN / BLU / CYA / MAG / WHT [TARGET VECTOR] menu [REF TARGET VECTOR]: Turn the vector for the reference target on or off. WHT is replaced with RED with A and B types. [OWN SHIP VECTOR] menu [VECTOR STAB IND]: Turn ON to show double arrow for ground tracking; single arrow for water tracking.
2. RADAR, CHART RADAR OPERATION 2. Select [7 BARGE] (B type) or [6 BARGE] (IMO and A types). 3. Select [1 BARGE MARK]. 4. Select [ON] to turn on the barge mark. 5. At [2 BARGE SIZE], enter length (three digits) and width (two digits) of the total number of barges. 6. Select [3 ARRANGEMENT]. 7. Enter the number of barges that will be in front of your vessel, row by row: 1) Select a barge row. 2) Spin the scrollwheel to set the number of barges in the row. (The maximum number is nine.
2. RADAR, CHART RADAR OPERATION 2.26 How to Adjust Brilliance of Screen Data You can adjust the relative brilliance levels of various markers and alphanumeric readouts displayed on the screen. 1. Right-click the [BRILL] button on the InstantAccess bar then select [Brill Menu]. [BRIGHTNESS] menu, page 2 [BRIGHTNESS] menu, page 1 2. Click the brilliance adjustment bar of the item to adjust.
2. RADAR, CHART RADAR OPERATION 2.27 Watch Alert The watch alert provides a flashing visual alert at regular intervals to remind you to monitor the radar picture for safety or other purposes. To enable the watch alert, open the [8 INITIAL SETTING] menu followed by the [4 ALERT] menu. Select [1 WATCH ALERT] and set desired watch interval. The [Watch] box appears at the bottom-left position. (The watch interval can also be selected from the [Watch] box when the watch alert feature is active.
2. RADAR, CHART RADAR OPERATION 2.28 Information Box The information box shows navigation data and, when following a route set on the chart display, route information is also shown. 2.28.1 Information box contents Navigation data • Depth, analog and graph • Current (tide) direction and speed • Wind direction and speed • Water temperature • Current and wind gauge Nav data requires appropriate navigation sensors and IEC 61162-1/2 sentences output from the sensor.
2. RADAR, CHART RADAR OPERATION Route information The route 1 information displays route name, plan speed, plan course, course to steer, channel limit, and off track. The route 2 information displays waypoint no., distance to WOP (wheel over point), time to go, planning turn radius, turn rate, next waypoint no., bearing to next waypoint. Click the [Route 1] or [Route 2] tab to find route information. 2 ROUTE10 10 2 17 123 2 T 0 10 27 123 2 T 08 250 2 00 45 4 3 123 7 T Route 1 2.28.
2. RADAR, CHART RADAR OPERATION 2.28.3 How to turn NAV data on/off Wind, depth, ocean current and water temperature may be set up as follows: 1. Open the menu then select [4 INFORMATION BOX]. 2. Select [2 SET NAV DATA]. 3. Set up the nav data referring to the table below. Item [1 DEPTH] Description Selects the unit of depth measurement, or turn depth indication off. [2 DEPTH GRAPH SCALE] Selects depth scale range. The depth for the last 30 minutes is plotted with a yellow line.
2. RADAR, CHART RADAR OPERATION 2.29 Interswitch The interswitch uses a network to transfer multiple radar signals to the monitor units connected in the network. A master/slave relation can be set for a single radar signal and that signal can be shown on multiple displays. Up to four antennas and four display units can be connected. Set the radar display and antenna groups from the [Antenna] button on the Status bar.
2. RADAR, CHART RADAR OPERATION 2.29.2 How to preset antenna and display combinations You can preset the antenna and display combinations for each antenna and display in the radar system. As an example, the procedure below shows how to select the no. 1 antenna unit for the no. 2 display unit. 1. Open the menu then select the [8 INITIAL SETTING] and [5 ANT SELECT] menus. 2. Select the display unit for which to select an antenna (at the next step). For example, select [DISP2] to select the no.
2. RADAR, CHART RADAR OPERATION • When connecting with FAR-2xx7 series radar When switching the antenna from FAR-3xx0 to FAR-2xx7, the image for FAR-2xx7 is displayed on the screen and each function is operative. However, when switching the antenna from FAR-2xx7 to FAR-3xx0, the following functions are not operative.
2. RADAR, CHART RADAR OPERATION 2.30 Dual Radar (B-type only) When installing two FAR-3xx0 series radars, the image from both radars (main radar and external radar) may be shown together on one radar display. This allows you to take advantage of the best characteristics each type of radar has to offer. The dual radar function is available only for the B type.
2. RADAR, CHART RADAR OPERATION 2.30.1 How to enable or disable the dual radar display Turn on the power of main radar and external radar to set them in standby. The dual radar function is not available when one of two radars is in TX (transmit) state or turned off. From the menu 1. Open the menu then select [1 ECHO] and [9 DUAL RADAR]. 2. Select [COMBINE] to enable the dual radar display. To disable the dual radar display, select [OFF]. 3. Close the menu. From the antenna button 1.
2. RADAR, CHART RADAR OPERATION Restrictions The followings are the restrictions of the dual radar function. • A REF (reference) mark can be entered on the display of the main radar but not the external radar. • TT targets can be acquired manually. [TT SELECT] is set to manual acquisition. • The reference position is set to [CCRP] (see section 2.33). Set the same CCRP position between two radars at the time of installation. • [ECHO AREA] is set to [CIRCLE] (see section 2.38).
2. RADAR, CHART RADAR OPERATION 2.31 Performance Monitor The performance monitor, installed in the antenna unit, produces a visual indication on the radar display screen when the radar transmitter power and the radar receiver sensitivity and tuning are within the prescribed limits. A graph is also provided and it shows degradation of TX/RX/Power over time. How to activate, deactivate the performance monitor To activate, deactivate the performance monitor, do the following.
2. RADAR, CHART RADAR OPERATION The radar is automatically set as follows when the performance monitor is activated.
2. RADAR, CHART RADAR OPERATION 3. Close the menu. Note: The lengths and location of the arcs may change with the direction in which the antenna unit is installed. Judge the strength of the echo that appears within 60° from arc location to confirm if the radar is working properly or not. Turn off the performance monitor when finished. The following illustrations in the table are the examples when [ARC] is set to [5]. Display Transmitter, receiver state Transmitter: Normal Receiver: Normal 8.1 NM to 10.
2. RADAR, CHART RADAR OPERATION 1) Set the radar settings as follows: • Range: 24 NM • Pulse Length: Long • A/C SEA: OFF (turn off manually) • A/C RAIN: OFF (turn off manually) • Echo Averaging (EAV): OFF • Video Contrast: 2-B 2) Adjust the gain so that a slight amount of white noise appears on the screen. Arcs for the performance monitor appear on the screen. 3) Set [PM GAIN ADJ] so that the outer arc faintly appears. The setting range is 0 to 255. Wait at least eight scans then adjust.
2. RADAR, CHART RADAR OPERATION Range and bearing are measured and graphics are drawn according to reference point as shown in the table below.
2. RADAR, CHART RADAR OPERATION 2.34 Drop Mark The drop mark is used to find the angle and distance from a point to your ship. This can be useful for marking a point to avoid while navigating to a destination. The drop marks can be shown or hidden on the screen. Drop mark The Drop mark box shows the angle and distance between the drop mark and your ship. Minimize button Drop mark no. (1 or 2) Drop angle Drop distance Note: The drop mark feature is inoperative when position data is lost. 2.34.
2. RADAR, CHART RADAR OPERATION 2.34.4 How to erase a drop mark Erase drop mark from menu 1. Open the menu then select the [5 MAP•MARK] and [1 MARK SETTING] menus. 2. Select [7 DROP MARK] (B type) or [6 DROP MARK] (IMO and A types). 3. Select [ON] or [OFF]. 4. Close the menu. Erase drop mark by trackball Right-click the applicable Drop mark box to show the context-sensitive menu then select [Drop1 Off] (or [Drop2 Off]). The drop mark and its data are erased. 2.
2. RADAR, CHART RADAR OPERATION 2.36 SART 2.36.1 What is an SART? A Search and Rescue Transponder (SART) may be triggered by any X-band (3 cm) radar within a range of approximately 8 NM. Each radar pulse received causes it to transmit a response which is swept repetitively across the complete radar frequency band. Screen B: When SART is close Screen A: When SART is distant Radar antenna beamwidth Echo from SART Echo from SART (Lines of 12 dots are displayed in concentric arcs.
2.
2. RADAR, CHART RADAR OPERATION 2.37.2 Alert list The [Alert List] displays the status of the latest 900 system alerts, in order of generation, latest to the earliest. To display the list, click the Alert list/log icon in the [Alert] box. The Alert list/log icon is light-blue when the list is displayed. A maximum of nine alerts are shown per page. Unacknowledged alerts are displayed in flashing red (alarm) or flashing yellow-orange (warning). The ZDA sentence is required to display time in the list.
2. RADAR, CHART RADAR OPERATION 2. Select [3 PRIMARY ALERT]. 3. Click the box to the left of an alarm name to show a circle to give that alarm the same priority as the alert category "Alarm." 4. Close the menu. Note: The priority is immediately changed for an inactive alert. For an active alert, the priority selected becomes effective when the alert is acknowledged and regenerated. 2.38 Echo Area The echo display area for the B-type radar can be selected for [CIRCLE] or [WIDE].