Radar Overlay
Optional
ECDIS implements an additional option for overlaying radar imagery on the ENC. The source of radar imagery is a radar processor or a network navigation radar.
When overlaying radar imagery, the radar image is converted from azimuthal projection to the chart projection (Normal Mercator conformal cylindrical projection) and the radar image scale is adjusted to the current ENC scale.
Important
To display radar imagery on the ENC, enable the Radar Layer.
Warning
ECDIS with Radar Overlay functionality is not a replacement for a navigation Radar.
The primary purpose of the function is to verify GNSS reliability and monitor the surface situation to identify discrepancies with the ENC.
The navigator must continuously monitor the correspondence between radar imagery and cartographic information and visual observations.
Caution
It is unacceptable to use Radar Overlay for determining target motion parameters, passing conditions, or calculating passing maneuvers.
Danger
The radar imagery transmitted to ECDIS is processed in the radar. The quality and completeness of radar imagery depend on the settings configured in the navigation radar.
Warning
This manual does not contain a description of methods and techniques for working with radar imagery. For correct use of Radar Overlay, the user must possess skills in working with radar imagery.
Creating a Radar Image Source
Menu path |
|---|
 →  → Radar → Add radar
|
Multiple radars may be connected, but only one radar can serve as the radar image source for ECDIS at any given time. When activating a second radar, the following notification will appear:
When activating the second Radar, the first Radar will be deactivated.
Tip
When multiple radars are connected, it is recommended to:
Select the radar with the best signal quality and minimal interference
Use the radar with a higher update rate when navigating in narrow waters
Regularly check the backup radar’s operability to ensure continuity of radar image reception
Note
Switching between radars may result in a brief loss of radar image for several seconds.
Before switching the radar image source, ensure that the switch will not create a precondition for a navigational incident.
RPU-1.3 Radar Processor Configuration
Important
The description of the radar image source configuration is of a general nature. The RPU-1.3 radar processor model is used as an example. For correct operation of the radar image source, configuration must be performed by a specialist with the appropriate technical knowledge and skills who has completed training with the ECDIS manufacturer.
Configuration of radar processor models implemented in the ECDIS software is described in the installation documentation.
Warning
Incorrect configuration of the radar image source may result in incorrect display of the radar image on the chart and an erroneous assessment of the navigational situation.
Source configuration:
Menu path |
|---|
→ → Radar → Settings |
No. |
Element |
Description |
|---|
1 |
Settings tree |
Hierarchical structure of the radar image source configuration sections |
2 |
Oscillogramm |
Signal oscillograms |
3 |
Return to Radar list |
Button to return to the list of all connected radar image sources |
Network settings:
If configured correctly, the connection statuses in the information group (4) will change and the data packet counters will update.
Tip
When configuring network parameters, verify:
Correctness of the radar image source IP address (must match the radar processor settings)
Network connection between ECDIS and the radar image source
Absence of port conflicts with other systems
Stability of data packet counters — they should continuously increase when the source is active
No. |
Element |
Description |
|---|
1 |
IP address |
Network address of the device (radar processor unit or radar station) |
2 |
Control Port No |
Network port number for device control |
3 |
Video Port No |
Network port number for video stream transmission |
4 |
Oscillogramm Port |
Network port for receiving RPU oscillogram |
5 |
Video data |
Data, status, settings, and state of the video stream |
6 |
Control Channel |
Data, status, settings, and state of the control channel |
7 |
Oscillogramm |
Data, status, settings, and state of the oscillogram |
8 |
Reconnect |
Force device reconnection |
Radar signals settings: set the mode in the Signal source dropdown list. By default, this parameter is set to standard (RPU-1.3). If all parameters are configured correctly and the radar image layer is enabled in Operational settings — see 3.8, the radar image will appear on the screen, and a Diagnostic group with information about the selected device’s status will be displayed in the settings window.
No. |
Parameter |
Description |
|---|
1 |
Signal source |
Select the signal source type
 |
2 |
Video |
Video signal settings |
3 |
Polarity |
Select polarity
 |
4 |
Input resistance |
Select input resistance
 |
5 |
Attenuator |
Select attenuator value
 |
6 |
Bearing Pulse |
— |
7 |
Polarity |
Select polarity
|
8 |
Filtering options |
Set value
 |
9 |
Marks for the period |
Set ruler length
 |
10 |
Accumulation. Pulse length indication. |
— |
11 |
Set frequency and length of short, medium, and long pulses |
|
12 |
Trigger |
— |
13 |
Polarity |
Select polarity
|
14 |
Filtering Options |
Set filtering parameters
 |
15 |
Heading Pulse |
— |
16 |
Polarity |
Select polarity
|
17 |
Filtering Options |
Set filtering parameters
|
Alignments. Antenna position: set the radar antenna coordinates relative to CCRP. If there is a discrepancy between the radar image and chart information, enter distance and angle corrections. It is recommended to perform these settings regularly.
Important
Critically important: Incorrect antenna position alignment causes displacement of the radar image relative to the chart, which may create a dangerous navigational situation. Alignment verification and correction must be performed:
During initial configuration of the radar image source
After repair work on the radar antenna
When systematic discrepancies between the radar image and chart information are detected
At least once a month during operation
Warning
If a discrepancy between the radar image and the chart is detected, immediate verification and correction of the alignment is required. Continued use of an incorrectly configured radar image source is hazardous to navigation.
Primary settings: enter the source name (1), set the required range scale. Using the controls and Gain, Sea, Rain parameters, adjust the signal detection thresholds. If necessary, use the Auto switches to enable automatic sea clutter suppression functions. Depending on the display model, adjust the display parameters so that the radar image is clearly visible on the screen.
Tip
Recommendations for display parameter configuration:
Gain: start with automatic mode; if necessary, adjust manually for optimal target display
Sea: this setting is especially important when navigating in rough sea conditions to suppress wave clutter
Rain: use during heavy precipitation to improve target visibility in rainy weather
Automatic modes: recommended for standard conditions; manual adjustment — for specific conditions
Note
Display parameters may vary depending on navigation conditions (open sea, coastal zone, narrow waters). Save optimal settings for different operating conditions.
Filtering: configure Noise interference suppression settings, set the parameters for the automatic Auto Gain and Auto Sea modes if they are enabled (see the item above).
Composite signal: configuration is performed when using a radar station that transmits radar data via a composite video channel. Configuration parameters depend on the type and model of the radar station used.
Monitor — diagnostics of output parameters and device status during configuration.
After successful connection and configuration, diagnostic information is displayed in the Monitor.
Oscillogramm — an additional window that opens/closes by pressing the button of the same name in the Radar settings section. Allows visual monitoring of radar signal parameters.
Network Radar Configuration
Important
The description of the radar image source configuration is of a general nature. The ONWA network radar is used as an example. Configuration must be performed by a specialist with the appropriate technical knowledge, skills, and qualifications who has completed training with the ECDIS manufacturer.
Configuration of radar models implemented in the ECDIS software is described in the installation documentation.
Warning
Incorrect configuration of the radar image source may result in incorrect display of the radar image on the chart and an erroneous assessment of the navigational situation.
Source configuration:
Menu path |
|---|
→ → Radar → Settings |
No. |
Element |
Description |
|---|
1 |
Settings tree |
Hierarchical structure of the radar image source configuration sections |
2 |
Oscillogramm |
Signal oscillograms |
3 |
Return to Radar list |
Button to return to the list of all connected radar image sources |
Network settings:
If configured correctly, the connection statuses in the information group (4) will change and the data packet counters will update.
Note
ECDIS contains the default settings of the ONWA Radar manufacturer. If necessary, modify the connection settings.
Tip
When configuring network parameters, verify:
Correctness of the radar image source IP address (must match the radar processor settings)
Network connection between ECDIS and the radar image source
Absence of port conflicts with other systems
Stability of data packet counters — they should continuously increase when the source is active
No. |
Element |
Description |
|---|
1 |
MAC |
Radar MAC address |
2 |
IP |
Radar network address |
3 |
Master |
Network address of the Radar control device |
4 |
Gate |
Network gateway |
5 |
Mask |
Subnet mask |
6 |
Video data |
Data, status, settings, and state of the video stream |
7 |
Control Channel |
Data, status, settings, and state of the control channel |
8 |
Status 1 |
Data and status of the radar image transmission port |
9 |
Status 2 |
Data and status of the parametric information transmission port |
10 |
Apply |
Apply the configured settings |
11 |
Reconnect |
Force device reconnection |
Alignments. Antenna position
No. |
Parameter |
Description |
|---|
1 |
Source coordinates |
Set the Radar antenna coordinates |
2 |
Source position |
Antenna installation point on the vessel diagram |
3 |
Range adjustment |
Distance correction — alignment of ENC and radar image |
4 |
Bearing adjustment |
Bearing correction — alignment of ENC and radar image |
Important
Critically important: Incorrect antenna position alignment causes displacement of the radar image relative to the chart, which may create a dangerous navigational situation. Alignment verification and correction must be performed:
During configuration of the radar image source
After repair work on the radar antenna
When systematic discrepancies between the radar image and chart information are detected
At least once a month during operation
Warning
For correct radar image overlay, the coordinates of the GNSS antenna(s) and the Radar antenna must be entered.
It is impossible to compensate for not accounting for the GNSS antenna position through antenna alignment.
Primary settings
No. |
Parameter |
Description |
|---|
1 |
Hardware |
Manufacturer name |
2 |
Name |
Radar name — entered during installation |
3 |
Transmit |
Radar scanner transmission indicator |
4 |
Radar image range |
Select the radar image display range. Does not change the range on the Radar. When the radar image range is increased, the radius of the displayed image increases. The displayed radar image cannot exceed the range set on the Radar control panel. |
5 |
Transparency |
Radar image transparency adjustment |
6 |
Brightness |
Radar image brightness adjustment |
7 |
Contrast |
Radar image contrast adjustment |
8 |
Master |
Master — always enabled. Control is not available. |
9 |
Signal adjustment |
Indication of the Radar control panel settings. Adjustment from ECDIS is not available. |
10 |
Radar control |
Indication of statuses set on the Radar control panel. Control from ECDIS is not available. |
Note
Display parameters may vary depending on navigation conditions (open sea, coastal zone, narrow waters). Save optimal settings for different operating conditions.
Monitor — diagnostics of output parameters and device status during configuration.
After successful connection and configuration, diagnostic information is displayed in the Monitor.
Oscillogramm — an additional window that opens/closes by pressing the button in the Radar settings section. Allows visual monitoring of radar signal parameters.
Configuring a Radar with Asterix Protocol Support
Important
The description of the radar image source configuration is of a general nature.
For correct operation of the radar image source, configuration must be performed by a specialist with the appropriate technical knowledge and skills who has completed training with the ECDIS manufacturer.
Warning
Incorrect configuration of the radar image source may result in incorrect display of the radar image on the chart and an erroneous assessment of the navigational situation.
Source configuration:
Menu path |
|---|
→ → Radar → Settings |
No. |
Element |
Description |
|---|
1 |
Settings tree |
Hierarchical structure of the Asterix protocol radar image source configuration sections |
2 |
Oscillogramm |
Signal oscillograms |
3 |
Return to Radar list |
Button to return to the list of all connected radar image sources |
Primary settings
No. |
Parameter |
Description |
|---|
1 |
Hardware |
Equipment name |
2 |
Name |
Radar name — entered during installation |
3 |
Radar image range |
Select the radar image display range. Does not change the range on the Radar. When the radar image range is increased, the radius of the displayed image increases. |
4 |
Signal adjustment |
Signal adjustment, surface and precipitation clutter compensation, and overall gain (depends on equipment implementation) |
5 |
IR |
Interference rejection |
6 |
Transparency |
Radar image transparency adjustment |
7 |
Brightness |
Radar image brightness adjustment |
8 |
Contrast |
Radar image contrast adjustment |
9 |
Frequency redraw |
Radar image refresh rate on screen, in Hertz |
10 |
Dead zone |
Dead zone radius adjustment |
Note
Display parameters may vary depending on navigation conditions (open sea, coastal zone, narrow waters). Save optimal settings for different operating conditions.
Alignments. Antenna position
No. |
Parameter |
Description |
|---|
1 |
Radar antenna position |
Radar antenna coordinates relative to CCRP |
2 |
Range Adjustment |
Range correction. Determination and compensation of the range correction is performed using a distant point object |
3 |
Bearing Adjustment |
Bearing correction. Determination and compensation of the correction is performed using a distant point reference |
Important
Incorrect antenna position alignment causes displacement of the radar image relative to the chart, which may create a dangerous navigational situation. Alignment verification and correction must be performed:
During initial configuration of the radar image source
Before each voyage departure
After repair work on the radar antenna
When systematic discrepancies between the radar image and chart information are detected
At least once a month during operation
Blank sector
When operating with a Radar, the Blank sector activates sectors within which the antenna’s high-power transmission is disabled.
No. |
Parameter |
Description |
|---|
4 |
Enable blank sector |
Enable the sector (depending on the radar model, two sectors may be supported) |
5 |
Start |
Sector start angle |
6 |
Width |
Sector width |
Note
If the equipment (radar) does not support Blank sector configuration from external devices, the sectors can be used to mask interference sectors. In this case, during primary signal processing, the specified sectors are excluded from processing and display.
Network settings
Hint
Transport protocol for Asterix — UDP.
No. |
Element |
Description |
|---|
1 |
Video Port No |
UDP port number from which the video stream is transmitted |
8 |
Reconnect |
Force device reconnection after entering the port number |
Monitor
Diagnostics of output parameters and device status during configuration.
After successful connection and configuration, diagnostic information is displayed in the Monitor.
Oscillogramm
An additional window that opens/closes by pressing the button of the same name in the Radar settings section. Allows visual monitoring of radar signal parameters.
Radar Overlay
Radar imagery overlay is enabled in the Operational settings.
Important
Correct radar imagery overlay requires heading data from the heading sensor.
ECDIS provides quick access to Radar overlay settings:
Menu path |
|---|
→  |
No. |
Parameter |
Description |
|---|
1 |
Selector |
Manufacturer name |
2 |
Radar Overlay Color |
Radar name — entered during installation |
3 |
Transparency |
Radar imagery transparency adjustment |
4 |
Brightness |
Radar imagery brightness adjustment |
5 |
Contrast |
Radar imagery contrast adjustment |
6 |
Signal adjustment |
Display of radar console settings. Adjustment from ECDIS is not available. Signal adjustment is possible only when the radar imagery source transmits raw signal and processing can be performed on the ECDIS side. |
7 |
Auto |
Automatic gain adjustment. Signal adjustment is possible only when the radar imagery source transmits raw signal and processing can be performed on the ECDIS side. |
8 |
Radar image range |
Selection of radar imagery display distance. Does not change the range on the Radar. When the radar imagery range is changed, the radius of the displayed image increases. The displayed radar imagery cannot be larger than the range set on the Radar console. |
9 |
Transmit |
Transmission indicator. Does not control high-power transmission activation on the radar |
Radar overlay settings contain controls for all connected radar imagery sources, which are grouped into sections. Above each section is the source name and a toggle switch to enable/disable the source.
Tip
ECDIS supports simultaneous use of only one radar imagery source.
Important
For the navigator: Radar imagery on the chart allows:
Visually monitoring the correspondence between radar targets and cartographic information
Identifying objects not displayed on the chart (ice, floating objects, small vessels without AIS)
Assessing radar operational efficiency in real time
Warning
Radar imagery limitations:
Radar imagery may not display small objects (wooden vessels, small yachts, ice)
In heavy sea and precipitation conditions, radar imagery quality may deteriorate
Radar shadows may conceal targets behind large objects
Radar imagery does not replace visual observation and other navigation aids
The radar imagery color is selected manually by the navigator, in accordance with their experience, skills, preferences, and prevailing circumstances. The color selection must exclude the possibility of incorrect reading of radar imagery, failure to identify navigational hazards, or incorrect assessment of discrepancies between the ENC and radar imagery.
Green radar imagery
Yellow radar imagery
Red radar imagery
Radar Overlay Warnings:
Text |
Category |
Condition |
Recommendations |
|---|
No radar video signal: <source name> |
Warning |
When radar video signal data stops being received |
check radar (radar processor) power-on status, cable connections, video channel settings |
No trigger signal: <source name> |
Warning |
When trigger signal data stops being received |
check connection of corresponding signals from the radar to the radar processor |
No heading signal: <source name> |
Warning |
When heading signal data stops being received |
check heading sensor status, check heading sensor connection (settings) to ECDIS and to the Radar |
No antenna bearing signal: <source name> |
Warning |
When antenna bearing signal data stops being received |
check antenna bearing data reception in the diagnostics window |
No connection to RP: <source name> |
Warning |
No connection to the radar processor |
check network settings, physical connection, radar processor power supply |
Important
Radar imagery overlay on the ENC requires heading, antenna bearing, trigger, and position data.
If transmission of any of these navigation parameters is absent, radar imagery overlay is not possible and will be disabled until the fault is corrected.
Removing a Radar Image Source
To remove a radar image source from ECDIS:
Menu path |
|---|
→ → Radar → Off → Delete |
After performing these actions, the radar image source will be marked for deletion (gray background) and become unavailable.
Warning
If this is the only radar image source, the radar image overlay on the ENC will cease. Ensure that removing the source will not affect navigational safety before performing the operation.
Tip
It is recommended to remove radar image sources only while the vessel is at anchor or when a backup radar image source is available.
Complete removal of the source from the system occurs only after ECDIS is restarted.
Tip
Shutting down ECDIS during a restart with radar image sources marked for deletion may take longer than usual. This is due to the correct termination of all running processes. If you encounter this behavior of ECDIS, simply wait for the shutdown and restart to complete.
Recommendations for Using Radar Image in Navigation
Important
The radar image is an additional tool for enhancing navigational safety, but it does not replace visual observation, the use of a compass, echo sounder, or other primary navigational aids.
Verifying Radar Image Overlay Quality
Before using the radar image for navigational purposes, ensure that:
Scale consistency: the radar image must correspond to the current chart scale
Overlay accuracy: radar objects (coastline, islands, headlands, isolated point references, navigational marks, radar beacons) must align with their representation on the chart
Signal quality: the radar image must be clear, without distortion or artifacts, as far as achievable under the current conditions and circumstances
Heading validity: ensure that the heading is received correctly (required for proper radar image overlay)
Warning
When using the Radar Overlay function, a guaranteed heading broadcast rate of at least 10 Hz is required. At a lower rate, under conditions of abrupt maneuvering and a large number of point objects, the radar image may “scatter.”
Danger
If a discrepancy between the radar image and the ENC is detected when matching known chart objects, determine the cause immediately.
It is important for the navigator to accurately determine the cause of the discrepancy between the radar image and the ENC, as the subsequent actions of the navigator may depend on the cause of the discrepancy.
When determining the cause of the discrepancy, it is important to exclude the influence of configuration changes:
antenna alignment has been disturbed;
changes have been made to vessel dimensions;
GNSS antenna coordinates have been changed or not set;
radar antenna coordinates have been changed or not set;
CCRP coordinates have been changed or not set;
the correct constant heading sensor correction has been changed or not set.
Warning
The navigational radar must also be subjected to the same checks.
Having excluded technical causes of the discrepancy, verify the vessel’s position using manual observations, as far as possible under the current conditions and circumstances.
If systematic drift or degradation of the GNSS signal is detected, perform the actions and procedures prescribed by the company.