Hi.
I'm looking for some advice.
I'm a land surveyor from the UK and have been surveying on sites for the past 20 years.
I've been reading and enjoying this site for many years. - Thanks.
A client who I have been working for regularly for 15 years has recently purchased his 2nd UAV drone which he uses
mainly for video recording large farm land areas ( which he owns ) , stone and sand quarries ( which he also owns) and construction sites which his company is working on ( mainly groundworks ). He also uses it to record pre site start conditions and to assist in him pricing works.
Throughout the years I have been surveying his quarries for excavation volume extraction quantities using mainly RTK GPS/GNSS and sometimes Total Stations.
I'm wondering if we should be looking at the possibility of using his UAV, in conjunction with new processing software to be carrying out this kind of work in his quarries. I'm thinking time saving, accuracy of data and safety issues of me walking/surveying the sites.
The UAV he has just purchased is a dji mavic pro 4k quadcopter.
I have read a bit on using UAVs for 3d survey work, but have never had any hands on experience.
Before I speak to him I want to find out if his UAV is suitable for the purpose ? I would be able to establish GPS/GNSS control points on the ground which could be recorded and used to coordinate transform to the site grids I have set up for each site / quarry.
I'm aware UAV Survey companies would be able to be contracted in to do this, but I think its something we may be able to do ourselves once we've climbed the learning curve.
If we could use this UAV for this purpose, what should we be looking out for in respect of software ?
I know there's quite a few software systems eg pix4D, agisoft, dronedeploy etc some more expensive than others. Do any users recommend any software system ?
Also Is there a minimum spec camera requirement I should be checking on his UAV ?
Furthermore, for the surveyors actually using UAVs for this or similar 3d surveying purposes, what pitfalls should I be aware of and avoiding ?
Basically If there's anything I should be looking out for or checking I'd appreciate a heads up.
Thanks in advance.
Andy
Lot's of this already discussed in this thread https://surveyorconnect.com/community/threads/tips-for-uas-photos-used-to-create-orthomosiacs.328743/
The camera on the Mavic Pro, while not an ideal photogrammetry grade camera, can still be used for such an application. Because of the rolling shutter effect, I would recommend to not fly faster than 15 mph, to prevent image blur. But with the combination of flying height (~200ft), GCP's, and high overlap (80%), you should be able to achieve vertical accuracy better than 0.25'. I prefer to use Pix4D software because they keep an updated database of initial camera parameters all the numerous UAS cameras, for a proper calibration. Other softwares require manual inputs for initial parameters.
Lee Thanks for the link - I never noticed that discussion.
Michael - Thanks for the comments . I'll bear them in mind.
Andy