Position Filtering and Smoothing

In this section:

Introduction

This command is executed from folders with schema type Single Beam or Multibeam and will do simple spike removal and smoothing of positions.
The command will modify the selected dataset(s).

When executed from a Multibeam folder the name of the command is Navigation Processing.
When executed from a Single Beam folder the name of the command is Position Filtering and Smoothing.

The Position Filtering and Smoothing dialog.

The content of the menu

The upper part of the menu contains the project name and the name of the active folder. 
The rest of the menus has the parts:

• The Spike filtering part
• The Moving average smoothing part
• The Survey data part

The Spike filter part

• Use Speed filter: Use this button to turn on and off the spike filter.

• Maximum speed (m/s) is the test criterion for if a position is a spike. If the calculated speed is larger than this test value, the position is assumed to be a spike.

The spike filter will not work if the dataset does not have a DateTime column. The removal of spikes can not be reversed.

The Moving average smoothing part

Moving average means that a number of positions are regarded, and the middle point is smoothed by getting the the average of all the other points.

• Smooth: Use this button to turn on and off the smooth filter.

• Window length in points is the length of the moving average filter.

• Iterations: The number of times performing the smoothing on the same position line.

• Smoothing mode: The command can be executed with two different options, Apply and Remove.
  • Apply means that the smoothing will be applied on the original positions. The original positions will be saved in columns named Original_X and Original_Y.
  • Remove means that the smooting will be removed and the positions set back to the original values.

The Survey data part

Select in the list on which Dataset to execute the command.