Deployment Preparation

Introduction

This guide is aimed to the the team responsible for deploying the Shipborne Lidar on a vessel or a rig. It will specify the conditions about system placement that need to be met for optimal performance. Also, it will specify the information Ocean Visuals needs to prepare the fastenings for the measurement device.

Deployment on a ship

The laser beam should be aimed at the point where the ship movement would not create foam. This depends on the shape and hydrodynamics of the ship. Most common case is shown on the figure on the right. The safest place would be in the bow of the ship, slightly to either side, so the beam would hit water in front part of the vessel.

The laser beam should not travel more than thirty meters before hitting the water. More than that and the signal will not travel back to the Measurement device. Beam distance may be calculated by taking the the square root of sum of h squared and l squared.

The distance will change due to waves and rocking of the vessel, so deploying the measurement device so the length of the beam approaches maximum distance limit should be avoided. The tolerance needed depends on the most likely working conditions and should be estimated based on experience.

Once the position has been decided please provide a drawing of the railing or other attachment point to Ocean Visuals.

Deployment on a rig

On a rig the position of the Measurement device should be chosen so it's field of view would not be blocked by ships or any other obstacle. The laser beam length limit is the same as with the deployment on a vessel and the change in length due to waves should be taken into account. Once the position has been decided please provide a drawing of the railing or other attachment point to Ocean Visuals.

Junction Box

Junction Box contains electrical and information technology devices that power and save the measurement results from the Measurement device. Junction Box needs to be connected to ships 240V power system and to the internet. The internet connection may be established via ships LAN or via independent networks(satellites, mobile network). Details of network connection should be agreed beforehand with Ocean Visuals.

The Junction Box needs to be indoors since it's not weather proof nor climate controlled. The cable connecting the Junction Box with the Measurement device should not be longer than 40 m in order to guarantee satisfactory data transfer reliability. The location for the junction box should be picked accordingly. The junction box dimensions are L:50cm W:40cm D:20cm.

Additional information

GPS antenna connected to Measurement device is sensitive to high power radio pulses from a radar. If possible select a position for the Measurement device so it would not be in line of sight with a powerful radar. If this is not possible separate antenna may be placed to a more suitable position and connected to Measurement device via cable.