Comparison of Ground Control Targets

[AJS410]

Hello all,

I am currently a senior in the Surveying program at the University of Akron. As a part of our coursework we are required to complete a capstone project and share the results in order to help the public and/or other surveyors.

For my project I made a comparison of different GCP targets. I assessed them for the ability of Pix4D to mark the centers, network precision and subjective qualities such as durability and the ability to easily set the target on varying surfaces.

I am attaching the final chart in PDF form. Please take a look and let me know what you think. I hope to be able to do more testing in the future as time and funds permit.

 

[jjbbrewer]

For my project I made a comparison of different GCP targets. I assessed them for the ability of Pix4D to mark the centers, network precision and subjective qualities such as durability and the ability to easily set the target on varying surfaces.

I am attaching the final chart in PDF form. Please take a look and let me know what you think. I hope to be able to do more testing in the future as time and funds permit.

Even though it's been quite a while, I want to say, "thanks" for your research and for posting this. I'm looking for some GCP targets to use in a couple of applications and I hadn't considered the usability you pointed out with the different solutions!

Again, thanks for posting this work. It definitely helped me!

 

[Airmapper]

I use the Sky High Bulls Eye myself, I love them. Super easy to store and pack in the field. They just stay in my work truck. I've found like a 3" Magnail holds them down perfect. If on pavement, I'll find a crack to drive it in so I can pull it up.

My employer had a full set of Propeller GNSS integrated GCP's, I told them to throw them away, sell them, whatever, I didn't want or need them. $50 and I had all I needed.

 

[adm_geomatics]

I still prefer orange 5-gallon bucket lids with a single 60D and shiner. It's unfortunate that noone will train their software to auto-rec them. Far easier to see than any of these in a wider variety of environments and materials. They don't warp and last for quite a long time making them reusable if needed. Oh, and they only cost $1.70 each. Pretty easy to swing by Home Depot in a pinch. Lowes blue lids are good for lighter materials.

 

[John Githens]

Like with many other topics in life, "it depends". I have both the orange lids and the larger black and white flexible, numbered targets. The lids with centered nails help when in thick brush areas. The other targets are fine for bare earth or pavement. There may - or may not - be an expectation that your company will retrieve the targets after a day's flights. Large numbers on the targets can be helpful later during photogrammetry work, or if walking a site with a client or contractor.

 

[jjbbrewer]

Like with many other topics in life, "it depends"

Absolutely. I like the idea (and cost) of the lids, but I needed something I could fit into my backpack along with my drone. I frequently take my drone on my dirt bike or mountain bike to remote areas so having all of the equipment small and compact is what I was looking for.

Nice ideas here, for sure.