The raw point cloud here is visualized by elevation. In this dataset, all points begin unclassified.
A quality point cloud is a great starting point for a GIS workflow analyzing and modeling the topography of an area. In Global Mapper Pro, you can create a topographic map from a point cloud. With Blue Marble Geographics‘ article, “Creating a Topographic Map from a Point Cloud,” learn how to make your own. Read more > >
A point cloud describes the vegetation, natural features, and manmade objects in a study area. The first step in creating data from a raw point cloud is classification. This process groups the points into defined classes that bring additional meaning to the point cloud data. Once classified, classes of points in the point cloud can be focused on or removed from consideration in the subsequent processes.
Global Mapper Pro’s Automatic Point Cloud Analysis tool provides built-in class models for some commonly identified point cloud classes: noise, ground, vegetation, buildings, poles, and powerlines. Not all of these classes can or need to be identified in every dataset. For datasets that do, the tool in Global Mapper allows multiple classification routines to be executed with a single click.
Moving beyond the basic classes, the geometric segmentation and custom classification functionalities in Global Mapper Pro can be used to identify features in the point cloud and apply additional classifications. In this dataset, geometric segmentation has been used to identify paved surfaces based on curvature and intensity values. A custom class is then applied to the identified ground points representing paved surfaces. Cars and other smaller features on the ground surface are left unclassified, making it easy to filter out these points in Global Mapper Pro.
Checking the boxes for the classes you would like to identify in the point cloud and then clicking Classify Features prompts Global Mapper Pro to analyze the point cloud and attribute points to all the selected classes.
The full article covers:
- Extraction
- Terrain
- Creating the map
With all the power of Global Mapper Pro’s analysis and editing tools, many different types of data can be generated from a single point cloud to generate a topographic map. To try out this workflow and other Global Mapper Pro tools with your data, download a 14-day free trial today.
Read the full article, or visit the Blue Marble Geographics website to find out more.
