Created by Mark Thomas, last modified on Nov 18, 2023

Sections

Introduction

Some more complex uses of Track Smoothing can be used to address the Noise Cloud problem. This involves identifying & smoothing the Points that lie within a noise cloud, and replacing them with a pause Point & resume Point located at the average location of all points in the cloud.

The pause & resume times are for the first and last points within the cloud & are kept in order to track movements better between breaks.

Smoothing Operation

A. All Points from tp to tr are removed.

B. New pp & pr Points are determined as follows:

  1. Timestamps correspond to the original pp & pr at tp & tr.

  2. Points are positioned at the same lat/long, which is taken to be the average of all removed Points (A)

Cases

Below are the cases to consider for Noise Clouds:

Case 1

Case 2

Case 3

Cloud is at Track start

Cloud is at Track end

1 or more clouds in middle

  • Collapse to 1 Point, start.

  • No ps/ts Point.

  • Collapse to 1 Point, end.

  • No pr/tr Point.

  • If time between tr & tr < duration threshold, merge points & set timestamp to average time of the 2 Points.

  • Allows recording where movement has many slow pauses, suck as rock climbing.

Attachments:

gis_ly-gis-9-noiseCloud-Before.jpg (image/jpeg)
gis_ly-gis-9-noiseCloud-After.jpg (image/jpeg)
gis_ly-gis-9-noiseCloud-Case1.jpg (image/jpeg)
gis_ly-gis-9-noiseCloud-Case2.jpg (image/jpeg)
gis_ly-gis-9-noiseCloud-Case3.jpg (image/jpeg)