What Do You Need to Know About Ground Control Points
GCPs are essential to drone mapping. You can increase the accuracy of your mapping, control the ‘roll’ of your survey, and define the boundary of your site by adding CompassData Inc. GCPs to your drone map. To learn more about GCPs, read the rest of this article. Then, you’ll be well-creating GCPs on your own. In addition, you can use GCPs to improve your drone map, too!
Enhance the accuracy of your drone map
Ground control points (GCPs) are the physical landmarks on the ground that photogrammetry software uses to place its drone on the map. The software then uses these landmarks to triangulate the drone’s position relative to other points on the map. This process increases the accuracy of your drone map, but GCPs are not necessary for all mapping projects.
The number of ground control points you use for your mapping depends on the size and terrain of your site. Experts recommend at least five, but 20 are possible, depending on your needs and equipment.
Control ‘roll’ of your drone survey
To make the most accurate measurements, you should place your GCPs on the ground as far apart as possible. A 20-acre landfill cell, for example, should have five GCPs. The highest and lowest points of the cell are set at a distance of at least 15 meters from each other. The middle portion of the cell should have three GCPs set at a minimum distance of 5 meters. Ideally, you’ll use at least five GCPs, but it all depends on the size and geometry of the survey site.
GCPs are large photo targets placed within the boundaries of a drone survey. They transform cheap consumer drones into professional-grade products that can be used for engineering, construction progress monitoring, and precise mapping applications. You can also use them for geo-referenced overlays and design documents. Ground control points are an essential part of any drone survey and are critical for ensuring accuracy. So, how do GCPs work?
Define the boundaries of your site
Ground control points (GCPs) are markers that define the boundaries of your site. An ideal scenario would be to place a GCP in every corner of the site and center. But, most sites are not quite so perfect. But, ground control points are an easy way to think about coverage. Here’s how to designate ground control points:
The number of ground control points depends on the size of the site. For a 20-acre landfill cell, for example, you should set five GCPs. Usually, a minimum of seven is safer, but a minimum of five points is generally recommended. Here’s an example of a well-controlled drone survey of a 20-acre site: 3 GCPs are placed at each corner, and the center portion has three GCPs to avoid “doming.” The lowest and highest points of the cell are set at least 15 meters apart.
Create GCPs
You must know how to Create Ground Control Points (GCPs) if you want to take aerial photos or videos of construction sites. GCPs are widely used for construction site inspection, stockpile management, project calculation, and tracking on-site productivity. The placement and spacing of the GCPs are crucial for accurate mapping, and the number of GCPs varies from project to project. If you don’t plan to use as many ground control points as you need, the maps you produce will be inaccurate and may even be damaged.
One of the first steps in creating GCPs is to determine the location of each one. GCPs can be created using various methods, from spray paint to a wooden stick of the appropriate size. Each GCP must be weatherproof. If you plan to use the GCPs to guide your work, you should ensure that they are placed at least 50 feet from the edge of the map and have at least one per major elevation.
