SeaDarQ System Description

The SeaDarQ system is dividable into hardware and software components. The hardware part from the SeaDarQ products are composed of high performance commercially available computer components. These commercially available and mass produced PC boards of multiple suppliers are used to ensure affordable investments and cost of ownership. In addition, world-wide service, maintenance and installation can be guaranteed. For the software, different packages operating on the same hardware are used to ensure functionality is maintained. The software is capable of managing all the radar data and combining it with information from other sensors and storing this real time on disc or ram. This creates an opportunity to obtain real time data acquisition from navigation radar, and to measure and process the radar images over time.

Computer Hardware: Standard Requirements Server computer with a high processing capability. Server computer should be mounted in a 19" rack and not placed more than 2 metres from the radar interface unit. Windows XP/2000 operating system - the SeaDarQ platform is based on a Microsoft environment, and therefore all types of connection to the system are possible.

Data Acquisition Software

The capability of the SeaDarQ system to obtain and display real time radar images of an operator-specified area of the sea surface on the screen, and to store these raw radar lines over time is a unique feature and a huge advantage over competitors. The SeaDarQ system, (based on a 14 bit video to digital convertor) digitises and stores raw radar images and processed images on ram or disc, and aggregates many co-located images taken in successive antenna revolutions to produce a time series of images. The storage capacity of these images is limited to the amount of discs and the discs capacity. Each radar line is approximately 8 Kbyte, and as such, storage time is dependant on the amount of discs and the size of the discs (back up of files can be made on CDs, with a further option of back up through DVD). Storage of processed data is dependant on the amount of images a user wishes to have, and is adjustable on the user interface. The system comes standard with 800 Gb of storage.

Optional Extras

Map

• It is possible to add a map as a layer under the radar image, if an additional computer and display is available.
• Any adjustments made in the map system will be visible on the SeaDarQ system.

Web Server

• A SeaDarQ web server offers functionality control over a distance and interchange of data with other platforms.
• This system can be controlled remotely and the data or images can be made available to multiple users, with password controlled access.
• The image recording timers can be activated via remote access to give virtually real-time information about clean up operations and show where the SeaDarQ system is located.

Radar Hardware

For the majority of maritime applications, the primary or secondary navigation radar can be used. This is because the sensor from the SeaDarQ system is built from commercially available navigation radar components. The specification of the radar influences the performance of the system - b etter results can be achieved with the SeaDarQ system when using a more accurate radar.

The detection range and resolution of the SeaDarQ system are dependant upon:

Antenna length

• A longer antenna will give a better resolution over a greater distance. We specify a minimum 8 feet antenna, and recommend 12 feet or larger.
• A longer antenna is characterised by a smaller opening angle, which provides a greater resolution.
• It is important to note that if an antenna is used with a relatively wide opening angle, the system is unable to improve this.

Height of the antenna

• If the antenna can be placed high above the water surface this will increase the detection range dramatically.
• We specify a minimum height of 15 meters.

Output power and sensitivity input

• A high output power is required with a more sensitive input. This will improve the detection range. If the radar has a low output power and low sensitive input, the SeaDarQ system is unable to improve this.

In summary, the system will, under every circumstance improve the capabilities of any radar.

Radar Specifications

• X band
• Minimum eight feet antenna.
• Fast turning, with minimum 48 rpm
• Vertical Polarisation
• Minimum output 25 kw
• If available, low noise amplifier input

Radar Brands

SeaDarQ successfully operates with the following radar brands and types:

• Gem
• JRC
• Terma
• Raytheon
• Kelvin Hughes
• Sam - Sea Hawk
• Litton Sperry Marine
• Any other radar with above mentioned outputs will operate with a SeaDarQ system.

Pulse

• Short or medium pulse mode

Required outputs from the radar

• Raw video signal (unfiltered signal)
• Trigger
• Azimuth
• North reset

Radar Signal Processor

• This is based on a dual Xeon processor from Intel, where each processor has four cores generating a dual quad core processor.

For some applications, a special wave guide is necessary. This wave guide can be fitted in the housing of many of the leading navigation radar manufacturers. The wave guide specification is different from the slotted wave guide. The specifications of this wave guide are:

The opening angle: 1 degree azimuth
The elevation: 24 degrees
Side Lobes: The best possible (less than -32dB)
Polarisation: Vertical

All specifications are specified by the manufacturer of the navigation radar components. In addition, the used measuring boards are specified by the manufacturer of the boards. In some cases, minor signal conditioning, such as impedance or level, is necessary to connect to the radar signals. For leading navigation radar components manufacturers, the interface box provides this.

When used on board a vessel, the SeaDarQ system compensates for the ship's movement via a connection to the vessels navigation instruments, such as heading and position GPS or DGPS.

The required navigation instruments outputs in NMEA format are:

• GPS/DGPS
• Heading (GYRO)

Installation of the SeaDarQ system

Installation of the SeaDarQ system can be completed locally. The computer must be connected to the radar video output, angle and North reset to the PC as indicated in the User Manual. Further, a power connection on the bridge must be provided and the PC must be mounted under conditions that guarantee enough cooling for normal operating temperatures. Vibration levels may not exceed the specification of the disc drives, and the radar must be installed by certified people from the radar supplier.