Usage Overview
The Radar Overlay system includes one PCI computer interface card that accepts and
processes video, trigger and azimuth from a marine radar transceiver. The
system provides a simple, flexible interface between a marine radar and ICAN's
ECS. This interface is for standard marine radars and it supports all low and
high speed scan rates. The system has been tested with scan rates up to 120 RPM
(prototype unit). A high speed antenna such as this provides improved target
detection for small targets at sea. This will benefit high-speed ships that
require faster scanning antenna to aid safe navigation, especially in the area
of obstacle avoidance. Those involved in search and rescue, iceberg detection
and coastal surveillance will also be impressed with the performance.
The radar processor provides 8-bit radar images (256 intensity levels). This
provides a much more detailed image, including shape and orientation of targets,
and land details such as buildings, roads and waterways. In addition, some of
the more subtle features of ocean features such as waves, ice and oil pollution
are more pronounced. Below is a screen capture of the "raw" radar data as
displayed in ICAN's ECS prior to data enhancement. Notice here the available
detail depicting the look of the waves and the coastline.
Integrating or averaging the radar signal over successive scans smoothes the
sea clutter, making it easier to detect targets. This is because the sea clutter
can vary considerably from scan to scan. In the below image the scan processing
level has been set to 16 revealing a potential target (visible on full screen
image).
By increasing the threshold level between 0 and 256 you can limit the amount
of the radar display values that are shown. In the below screen grab, the
threshold has been set to 100 thereby removing much of the background or weaker
return values. As well, STC (Sensitivity Time Control) has been turned on
removing much of the clutter in the immediate area of the vessel. STC reduces
the gain at close range (where maximum sensitivity is not generally required),
allowing more gain to be applied to data from farther ranges where more
sensitivity is desired. This increases the ability to detect small targets at
longer ranges. Viewing the below image at full-screen shows that there is a buoy
at the exact location of the radar target.
The ability of the radar data to accurately display features such as the
coastline is shown in the two graphics below. The first image is an S-57 chart
(vector) showing radar data (in green). The second image is in the same area but
depicts the radar data over a BSB (raster) chart. In both cases the chart shows
through the radar data as is required by ECDIS guidelines.
If you have any further questions regarding ICAN's Radar
Module
please contact us at
sales@icanmarine.com
