Hoodman Corporation makes highly visible and ground control point kits for aerial mapping projects using photogrammetry and Lidar. Kits come in conveniently numbered 5 packs or 10 packs. Each GCP is 3 feet in diameter and collapses to 30% of its original size. The weighted perimeter of each GCP keeps the position without the need to stake them down. The convenient carry bag keeps your kit compact and easy to work out of.