Double-click on the next photo and repeat the placement of the flag in the center of the target. In order to get a true sense of these errors, at least three GCPs need to be placed in a minimum of three photos (projections) followed by a least-squares adjustment. Notice now that the columns Error (m), Projections and Error (pix) now have values in them indicating the relative (pix) and absolute (m) error associated with placing that marker.

10 First GCP marker flag placed in the center of the target. The goal is to left-click and drag the marker flag to the centre of the checkered GCP as per Fig.

Select the next photo if that’s the case. It may be that the actual GCP is not visible in that photo! The flag can initially be several meters from the target due to the absolute positional error of the RPAS GPS. Now, in the Photos pane along the bottom of the main display window, all the photos that GCP 1 appears in are shown.ĭouble-click the first photo and zoom in on the flag for GCP 1. In the Reference pane, notice the list of nine markers with their corresponding Easting, Northing and Altitude. If the markers flags are not visible in your image, click Show Markers in the main toolbar. 9 showing the initial locations of nine control points. You should now see a view similar to Fig. 8 Import CSV parameters for GCP import.Ĭlick Yes to All when asked whether to “ Create new marker?”. 8, paying close attention to the Start import at row value ( 2 in this case) and click OK. Adjust the Coordinate System, Delimiter and Columns as per Fig. In the Reference tab, select Import Reference, navigate to where your GCP file is stored (i.e. For this exercise, the GCPs are in a comma-delimited format (CSV) which can be imported directly by MetaShape. MetaShape will accept GCP files in a range of different formats and file types.

In this chapter, the goal is to add ground control points (GCPs) and use them to refine the relative and absolute orientations of the photos with reference to a real-world coordinate system. Chapter 1.3 – Ground Control Points Overview

Tutorial agisoft metashape professional