Ground Control Points

I have spent decades setting large cross type GCPs (aerial targets) for high elevation manned aircraft using film technology similar to the one below. Larger GCPs were needed on film imagery because it made it easier to find the target.

These type of GCPs took time to set and used a lot of material. It would take several days to set all of the GCPs before the flight so they had to be durable and weather resistant.

Digital cameras and low flying UAVs have changed the way that ground control points (GCPs) are set and the material they are made of.

High resolution digital cameras are a game changer. The GCPs can now be smaller and all kinds of material can be used. With digital imagery, the targets are easier to find at any zoomed level.

The above chevron is 2' x 2'. This style is used for lower flying manned aircraft as well as UAVs. It takes about 5 minutes to set up.

GCPs for UAVs can be a lot smaller. I have used paint marks, paint stripes, water valves, manholes, corner of concrete sidewalks, etc.

I use cardboard pizza rounds most of the time. They are cheap, quick and easy to set. They are only good for a day or two so the flight needs to happen soon after they are set. They are not waterproof so if it rains they will shrivel up and decay quickly.

I have experimented with plastic rulers, whiskers and so forth.

My latest test is with a more permanent GCP using 3D printed ABS material.

I am using these more permanent GCPs for the site I am setting up to do multiple flights at different AGLs and Overlaps to determine where the "Sweet Spot" is for different drones/cameras. These GCPs will eventually decay and break down over time but should last long enough to get several test flights in.

These small GCPs are actually quite easy to see in the imagery even when zoomed out.

Conclusion

Finding easier and cheaper ways to set GCPs will continue to be tested. UAVs are here to stay and are being utilized by more and more surveying and engineering companies each day.

If you haven't yet implemented a UAV program into your surveying business, you probably have thought about it.

The first six books in my "Survey Mapping Made Simple" book series should answer most of your questions and concerns.

Reliable and accurate results can be obtained from a UAV with the right camera and flying techniques.

Archived Email Posts

If you like the information provided above and would like to see more in future email posts, then consider purchasing some of my books to help support the effort. As all of you know, computer hardware, software and drones costs money. I put 100% of my book sales back into the business to write more books, buy drones to test and so forth.

Thank you all that have supported this effort. It is greatly appreciated.

www.cc4w.net

Unique Surveying Math and Mapping Book Series,

Training and Reference Material Study Guides.

Open Survey Mapping Study Guide here .

Open Surveying Mathematics Study Guide here .

Surveying Mathematics Made Simple Book Series.

One of the biggest hurdles to get through on the FS and PS exams is the surveying mathematics. It takes dedication to study and practice to master the math needed for the exam and throughout your surveying career.

This series of books will provide the necessary tools and step-by-step processes to bring it all together.

Each book in this series will build upon the last one to help you to become a true surveying professional.

Survey Mapping Made Simple Book Series.

Almost anyone can learn to fly a drone. Not everyone can truly master the skills that are required to use a drone for aerial survey mapping and get professional results.

This series of books will provide the necessary tools and step-by-step processes to bring it all together.

Each book in this series will build upon the last one to help you to become a true professional remote pilot.

All books available on Amazon.com

Join Our Mailing List

Surveying Mathematics Made Simple, LLC

Creative Computing 4 Windows

Survey Mapping Made Simple