Creating Ground Control Points (GCP's)

Ground control points (GCP's) are objects placed on the ground with specific locations in the area of interest so the processing and accuracy of UAS imagery can be increased on Pix4D. The GCP's that have been created will be used for the next couple projects.

Creating ground control points required a multiple stage process. The materials we used were cloth blankets for covering the cement, spray paint, plastic material about 1/4 inch thick, and a table saw. Of course all proper safety gear and equipment were used during the cutting process. First we had to cut the plastic material into squares using the table saw (figure 1).

Figure 1. Dr. Hupy and two students using the table to cut the plastic material into squares.

The next step was to use the pink spray paint and place a wood triangle stencil on the plastic material. The plastic squares were laid down on the cloth so the spray paint would not get on the floor. There was two triangles painted on opposite sides for each individual square. On the sides that were not spray painted with a pink triangle, a number was spray painted yellow to keep track of each individual GCP (figure 2).

Figure 2. The GCP's  that have been spray painted and completed for drying.

After all the GCP's were spray painted, we set them up against the wall for them to dry. Afterwards we discussed UAS related material in the shop.