Laser Dolphin sub sea paravan 3D camera system
* High speed sub sea imaging and mapping system for operations over large areas
* Efficient paravan design for high speed operation in rough sea
* Active gated laser camera with capabilities to see through particles in the water to beyond the normal visible range
* 3D laser radar mapper capable of real 3D measurement of sea bed and objects in this area, global coordinate output
* Booth gated camera , ortho cameras and 3D mapper in same efficient paravan housing
This makes it easy to move over large areas and scan them by the camera or Ladar unit. On the surface there is a control unit with screens and operators panel with DGPS interface.
LaserView gated sub sea camera use green pulsed light to penetrate through the visibility barrier of particles and dirt in the water. The nano second pulses strobes the light in its flight and can create back ground lightning without blocking of the particles in front of the area. Range is 2-5 times better than other cameras.
GeoMapper is a laser radar unit also using green light to penetrate the water. The high speed system measure the distance where it points and as we know the angles we can generate a 3D coordinate system related to the Laser Dolphin unit.
INS inertial navigation unit calculate the heading of the Laser Dolphin so the coordinates are globally orientated. Depth meter gives depth. Gyros gives attitudes
DGPS unit at surface defines the latitude and longitude and by a unique correction system the DGPS antenna position is translated to the coordinate system of the Laser Dolphin unit down in the sea.
The outputs is a global coordinate system of what is scanned by the Ladar unit . The LaserView images are also connected into the same geometry and have global coordinates.
This is the chassis of the system with the enclosure for the electro optical unit and electronics. During tests we have found a solution which gives a very calm and good stability in movements when towed by the boat hanging in a wire. The movement is balanced to be horizontal independent of speed.
For low speed we can have the attitude control improved by setting the rudder unit tilted in 1-2 ways to compensate for water currents. We do also have a static rotation thruster making the system capable of rotating around its own axis over 360 degree.
The enclosure is made in 50 mm thick water resistant aluminium and epoxy painted for best resistance to wear. This design can handle over 300 meter in depth.
Windows are easy exchangeable in stainless steel flanges.
Typical weight is about 400 kg totally with laser radar included.
Movements are very stable but still we add a INS attitude gyro system. This measures the inclinations and movements and can compensate the trajectory to be fully compensated. This do also include a solution for geographical heading.
Sonar unit can be installed in the front part and it scanns the area in front of Laser Dolphin to help the operator to control the movements. The scanned area is 90 degree and range is 150 meter front and 100 meter in depth related to the Laser Dolphin unit
Active gated laser camera Laser-View
The active gated laser camera is unique in its characteristics in penetrating water beyond the barrier of particle scattering. The laser gives green light with good transmission in water and is pulsed to less 10 nano sec long pulses. The irradiated field is about 45 degree in angle
The camera is an intensified camera with very exact control of the exposure time ( nano sec level ). This makes it possible to strobe and freeze the light in its flight . Then you can set a desired area where you want to look and discriminate all other ranges away.
You can control the settings to what fits the water quality and application best. Operator can arrange a front illumination of objects you want to see or a back ground illumination. This makes it possible to see the viewed objects as a dark shadow on a white background. For navigation the last version admits the best range.
The screen shows the image as a TV image in B/W. Operator can easily set at what distance to start to view and where to stop. This is very easy and obvious. Laser-View is a state of the art solution but not complex in its operation.
Geo-Mapper system is a function block inside the Laser Dolphin. The system is based on a scanning laser distance meter using green light to get best penetration of sea water. The distance meters laser beam is scanned in a single axis pattern and when the movement of Laser Dolphin is added it will generate a matrix at se bottom. The distance meter is a high speed device using smart algorithms to see longer than normal sighting depth.
Geo-Mapper system can generate up to 5000 independent 3D points per sec . Range is from 1 meter to 25 meter in distance. Accuracy is less 5 mm in close end and about 50 mm at far end. 2004 we expect to have a solution for less 1 mm accuracy all
over the range
Ortho-cameras mounted in the scanner unit take a photo of scanned area and it is adjusted so each laser measurement have a known pixel relation in the camera. This makes it possible to make real 3D photos by mixing the 3D database with the pixel values of the camera unit.
Geo-Mapper and the Laser-View are calibrated to the INS gyro system. This state of the art INS system give attitude and movements of the platform and coordinates all measurements to be related correctly. Geographical heading is measured.
| LaseroptronixAB |
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Telephone 46-70 714 04 70
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| Enhagsslingan 23 |
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| 187 40 Täby |
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Säte i Täby Kommun Glimmervägen 8 187 34 Täby / Sweden |
| Sweden North Europe |
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Created 2005-10-27 by Allan Jansson
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