Consultancy Modelling and Optimization

Modelling squat Westergat

By 'Rijkswaterstaat Directie IJsselmeergebied' the vessels the Westergat and the Markermeer are used for depth measurements in the Keteldiep. Because of the cleaning up of the polluted bottom of the Keteldiep it is important that the depth is measured as accurate as possible. From different investigations it appears that the squat is one of the most important error source.

After the analysis of the squat of the Houtvliet and the optimalization of the accuracy of the depth measurements of the Markermeer the squat of the Westergat has been modelled. The squat is the sinkage of a vessel caused by it's speed and depth. On board of the Westergat is the Rwslod-measurement system within a squatmodel is implemented. This squatmodel has been optimized with speed, depth and squat measurements.

In the figure below the squat measurements (red) and the results of the squatmodel (green) are given of a survey lane. The speed of the Westergat increases along the lane.

The squat measurements comes from a dGPS-RTK measurement system, in which the (x,y,z-) position of the vessel are given by satellites.

An extensive report is given in 'Modellering squat Westergat' (october 1998).