Drone Point Cloud Accuracy

Discuss all Leica Geosystems related issues here.
Post Reply
User avatar
dineshkimraj
I have made 70-80 posts
I have made 70-80 posts
Posts: 77
Joined: Tue Apr 02, 2019 8:15 pm
Full Name: Dinesh Kimraj
Company Details: Facilities Construction Consultants Ltd
Company Position Title: Senior Reality Capture Tech
Country: Trinidad and Tobago
Linkedin Profile: Yes
Has thanked: 11 times
Been thanked: 2 times

Drone Point Cloud Accuracy

Post by dineshkimraj » Wed Jul 10, 2019 6:25 pm

Good day guys.
We have a project where we need to scan a two metre pile located about 51 metres offshore, i.e, the closed we can get to it is 51 metres. We are currently pursuing the idea of using a drone to take pictures of the piles and then create a point cloud. We would then tie in this cloud with our point cloud obtained using a RTC360.

So my question is, what is the accuracy of using the drones (DJI Phantom most likely) to gather the info.

Thanks
Dinesh

Ioannis
V.I.P Member
V.I.P Member
Posts: 201
Joined: Sun Jul 24, 2016 6:19 am
Full Name: Ioannis Papas
Company Details: techical office
Company Position Title: CEO
Country: EU
Skype Name: -
Linkedin Profile: Yes
Has thanked: 1 time
Been thanked: 4 times

Re: Drone Point Cloud Accuracy

Post by Ioannis » Wed Jul 10, 2019 8:16 pm

It depends on the flight height and how you spread gcp imagine that the final mosaic is a table and the legs is gcp. From mine experience with drones you can archived in x,y 3,4 cm and in z from 5cm to 10 cm. But it depends in many other factors..

User avatar
stutosney
I have made 50-60 posts
I have made 50-60 posts
Posts: 58
Joined: Tue May 15, 2018 5:55 am
Full Name: Stuart Tosney
Company Details: Vitruvius Ltd
Company Position Title: Lead Surveyor
Country: New Zealand
Linkedin Profile: Yes

Re: Drone Point Cloud Accuracy

Post by stutosney » Thu Jul 11, 2019 5:41 am

Hi Dinesh,

It depends on the camera attached to the drone as well as whether you will have any GCP's for the drone to pick up. I would also be cautious about relying on scan data from an RTC from 50 metres away, though if accuracy isn't a major factor, it should be fine.

Good luck

ABeckett
I have made 10-20 posts
I have made 10-20 posts
Posts: 12
Joined: Tue Apr 10, 2018 2:05 am
Full Name: Andrew Beckett
Company Details: Hellier Mcfarland
Company Position Title: 3D Environments Manager
Country: Australia
Linkedin Profile: No
Been thanked: 1 time

Re: Drone Point Cloud Accuracy

Post by ABeckett » Thu Jul 11, 2019 6:08 am

Offshore as in surrounded by water? I feel like that's going to cause issues with the photogrammetry calculation. I'd suggest a highly accurate scanner. Maybe something like the Leica P series.

MajorDomo
I have made 80-90 posts
I have made 80-90 posts
Posts: 81
Joined: Mon Feb 25, 2019 4:42 am
Full Name: Major Domo
Company Details: VeritasVfx
Company Position Title: ceo
Country: Portugal
Linkedin Profile: No
Been thanked: 4 times

Re: Drone Point Cloud Accuracy

Post by MajorDomo » Thu Jul 11, 2019 8:55 am

Coverage is a red herring, you need parallax. moving water=no parallax. Make sure you get some wide shots to add that to the calculation.

User avatar
dineshkimraj
I have made 70-80 posts
I have made 70-80 posts
Posts: 77
Joined: Tue Apr 02, 2019 8:15 pm
Full Name: Dinesh Kimraj
Company Details: Facilities Construction Consultants Ltd
Company Position Title: Senior Reality Capture Tech
Country: Trinidad and Tobago
Linkedin Profile: Yes
Has thanked: 11 times
Been thanked: 2 times

Re: Drone Point Cloud Accuracy

Post by dineshkimraj » Thu Jul 11, 2019 2:02 pm

Thanks for the suggestions, using a scanner with a better range might be our best option.

User avatar
gsisman
V.I.P Member
V.I.P Member
Posts: 282
Joined: Fri Oct 07, 2016 1:51 pm
Full Name: Steve Long
Company Details: Montgomery County DOT _ MD
Company Position Title: Land Survey Supervisor
Country: United States
Skype Name: gsisman1
Linkedin Profile: Yes
Has thanked: 32 times
Been thanked: 7 times

Re: Drone Point Cloud Accuracy

Post by gsisman » Thu Jul 11, 2019 5:49 pm

stutosney wrote:
Thu Jul 11, 2019 5:41 am
Hi Dinesh,

It depends on the camera attached to the drone as well as whether you will have any GCP's for the drone to pick up. I would also be cautious about relying on scan data from an RTC from 50 metres away, though if accuracy isn't a major factor, it should be fine.

Good luck
If you're using the RTC360 make sure you are having multiple targets onshore about the same distance or maybe 30m from the scanner and they are tied in elevationwise . this will counter the effect of the less accurate non-dual axis compenstor IMU. Are you not able to see all the way around the pile? Is that the purpose of the drone?

User avatar
stutosney
I have made 50-60 posts
I have made 50-60 posts
Posts: 58
Joined: Tue May 15, 2018 5:55 am
Full Name: Stuart Tosney
Company Details: Vitruvius Ltd
Company Position Title: Lead Surveyor
Country: New Zealand
Linkedin Profile: Yes

Re: Drone Point Cloud Accuracy

Post by stutosney » Thu Jul 11, 2019 9:28 pm

dineshkimraj wrote:
Thu Jul 11, 2019 2:02 pm
Thanks for the suggestions, using a scanner with a better range might be our best option.
If you need any help, I'll happily pop over to T&T!

User avatar
3DForensics
Global Moderator
Global Moderator
Posts: 1885
Joined: Mon Aug 03, 2009 1:52 am
Full Name: Eugene Liscio
Company Details: AI2-3D Forensics
Company Position Title: Owner
Skype Name: eliscio
Location: Toronto, Canada
Been thanked: 1 time
Contact:

Re: Drone Point Cloud Accuracy

Post by 3DForensics » Thu Jul 11, 2019 9:53 pm

I would say you could easily run a test on a known item. Scan it with the RTC and then photograph with drone at same distance as your real project. Compare and you will have a very good accounting of what is possible.

E

MajorDomo
I have made 80-90 posts
I have made 80-90 posts
Posts: 81
Joined: Mon Feb 25, 2019 4:42 am
Full Name: Major Domo
Company Details: VeritasVfx
Company Position Title: ceo
Country: Portugal
Linkedin Profile: No
Been thanked: 4 times

Re: Drone Point Cloud Accuracy

Post by MajorDomo » Thu Jul 11, 2019 10:30 pm

Just don't forget to do that test with water surrounding the object. Or mask the ground.
Otherwise you will get a false positive, parallax is the basis of photogrammetry. Water will reduce it severely.

Post Reply

Return to “Leica Geosystems”