Phantom 4 - Survey Grade Mapping

[Leif Johnston]

Hi all,

I am currently working in mining and seeking advice on whether or not the Phantom 4 is accurate enough for 3d mapping to achieve less then 5cm in 'XYZ' values.

I am very new to drones but have been researching quite a bit over the last couple of months and just need a few things clarified before I can put together a proposal to my boss for the Phantom 4. As I am in mining cost is a big thing these days and well they don't want to spend anything so therefore I need a cheap drone that can do want I'm asking but within tolerances.

My first thought was the Inspire with either the X5 or X5R camera as I know these cameras can deliver results but seeing the size of Phantom 4 camera I have my doubts. However the cost difference is quite dramatic, i.e. Phantom 4 will cost around $4k (AUD) total package and the Inspire will be around $8k. I have read on various forums and responding emails that the Phantom 4 will do the job, I just need to be 100% sure before I put this through to my boss...

I will be using ground control stations to help achieve the results I'm chasing and also have been looking at Agisoft Photoscan Pro for the editing side of things. The main type of work I will be doing is stockpile surveys.

Can someone please help me on this questions and what unit is better for achieving this and share there own experiences and what settings they have used.

Thanks in advanced.

Leif

 

[Teo Morabito]

DroneDeploy: Powerful cloud-based drone software. is a good mapping tool,
It's fairly accurate, you just need to experiment with the settings (fly higher or lower, more camera angle (45°) if doing 3D work of a building for example (oh and don't neglect the amount of overlapping between pictures, more is better for accuracy)
Maybe best to contact the company directly.
The P4 will certainly give you the image data, the most important part is the software that uses the data to create the map.

 

[fberna]

we do perform 3D mapping -photogrammetry- with the P4.

We use either Mapmadeeasy or Altizure to drive the P4.

60 m high with give you 2cm/pixel which for us is good enough.

Feel free to contact me if you need more info or some files as example.

Still do not get how it will cost more than 3000 usd to get a P4 with all accessories....

 

[AlexSP]

That level of accuracy and GPS precision can only be attained with the use of GCP (ground control points) or a RTK (real time kinetic) drone, like eBee or other (you can build from kits too, including DJI's).

If you're looking for a fully aerial and shortest time workflow then it's best to go with RTK, as GCP takes more resources. But the starting cost is higher since RTK is expensive. There's always a trade-off so depends on exactly what your needs are, the resources available and the demand.

"Prosumer" drones like the P4 can't get cm-level results alone, only feet-level. You can choose higher-accuracy cloud processing from Pix4D or Drone Deploy or map overlay and georeference with Maps Made Easy in their top level plans, but still a more precise ground positioning reference system during capturing is needed.

 

[fberna]

I assumed that the use of GCP was already taken into account!

The P4 alone won't give you any survey grade result. The result won't be correctly scaled and the whole plane will be tilted, with the part further away from the beginning of the flight showing -wrongfully- at an higher elevation.

Using GCP solve entirely the problem and you do get easily into the 2 to 3 cm precision mark. This is however linked to the precision of your ground points.

So if you can make use of GCP through a RTK GPS or official points and a total station, there is no need to heavily invest into RTK drones.

 

[AlexSP]

I assumed that the use of GCP was already taken into account!

The P4 alone won't give you any survey grade result. The result won't be correctly scaled and the whole plane will be tilted, with the part further away from the beginning of the flight showing -wrongfully- at an higher elevation.

Using GCP solve entirely the problem and you do get easily into the 2 to 3 cm precision mark. This is however linked to the precision of your ground points.

So if you can make use of GCP through a RTK GPS or official points and a total station, there is no need to heavily invest into RTK drones.

Well said!

 

[Meta4]

My first thought was the Inspire with either the X5 or X5R camera as I know these cameras can deliver results but seeing the size of Phantom 4 camera I have my doubts. However the cost difference is quite dramatic, i.e. Phantom 4 will cost around $4k (AUD) total package and the Inspire will be around $8k.

The big advantage of the Phantom over the Inspire is that it has a better battery life/flight time so it allows you to cover a bigger area each flight.
And by the time you put the heavier and more expensive X5 camera on the Inspire, your flight time takes an even bigger hit.
The X5R would give you no advantage for still images.

 

[fberna]

additional info:

IF you think you would be performing mapping near any airport forget the DJI. The geofencing can be temporarily lifted by DJI after your present some documents, but this won't work with any of the previously indicated software used to drive the copter for acquiring the images.

 

[AlexSP]

The big advantage of the Phantom over the Inspire is that it has a better battery life/flight time so it allows you to cover a bigger area each flight.
And by the time you put the heavier and more expensive X5 camera on the Inspire, your flight time takes an even bigger hit.
The X5R would give you no advantage for still images.

I can back that up. The P3 (and of course the P4) is an excellent mapping drone, so much so I'm selling my I1 with very little use. My P3P can perform one-shot surveys where the I1 may need a switch of batteries. Not to mention the whole carrying-unpacking-assembling-preparing procedure which is a lot more simpler with the P3.

 

[Leif Johnston]

Thank you all for your responses!

I am going to be definitely utilizing ground control points as this is the only way to get the accuracies I need and from what I've been reading I might need to play around with the altitude to achieve my required resolution.

I wont be even thinking of an RTK drone as they are still really expensive and my boss will probably just laugh at the cost...

 

[AlexSP]

More like he'd CRY eh!? Lol

Yep, ground RTK is readily available and unexpensive, makes much more sense business-wise most of times indeed

Best luck!

 

[Leif Johnston]

Another couple of questions...

• Has anyone used or had experience with an upgrade lens from Peau Productions? You can get a 16 megapixel for around $100, not sure if this is worth it?
• In regards to Apps, what is the best one for surveying way points etc. I'm will be using Agisoft Photoscan for editing so does it matter what app use?
• What camera/app settings work best?
• Is it better use apple or android phone or tablet?

Thanks again!

 

[TFV]

Hello,
I am new using drones and I would like to know in which file are the flight coordinates, I have a phantom 4. I need gereference the videos and photographs that I get with the drone to map vegetation, is this possible?
Thank you.

 

[Dinerve]

Hello,
I am new using drones and I would like to know in which file are the flight coordinates, I have a phantom 4. I need gereference the videos and photographs that I get with the drone to map vegetation, is this possible?
Thank you.

If you're talking about stills, I believe these are geotagged, so you should be able to retrieve the coordinates with any exif viewer.

Also, question is a bit off-topic.


Sent from my iPad using PhantomPilots

 

[LucioRom]

we do perform 3D mapping -photogrammetry- with the P4.

We use either Mapmadeeasy or Altizure to drive the P4.

60 m high with give you 2cm/pixel which for us is good enough.

Feel free to contact me if you need more info or some files as example.

Still do not get how it will cost more than 3000 usd to get a P4 with all accessories....

Hi, I have a P3 and I am looking to do Telecom Antennas Surveys. I need to be able to measure the Azimuths of the antennas in the towers. Do you know how can I do that? or if there is any accessory for the camera or Apps that can provide the azimuth the camera is pointing?

 

[fberna]

Hi, I have a P3 and I am looking to do Telecom Antennas Surveys. I need to be able to measure the Azimuths of the antennas in the towers. Do you know how can I do that? or if there is any accessory for the camera or Apps that can provide the azimuth the camera is pointing?

as in every photogrammetry work you need to geo reference with ground points.

Once you have them your view from above is perfectly oriented, so using the orthophoto or orthomosaic is it il called in photoscan, knowing the N is at the top you will be able to measure the azimuth with more than enough precision.

 

[Spatial Analytics]

Hi there,
Thought this thread needed revitalising.
I have built a cradle and timing capture device for the Emlid Reach RTK/PPK unit. When fitted on my Phantom 4 it captures precise timing and raw GPS data for post processed RTK (can capture RTK but why carry the extra weight?).
With this on my P4 I get sub 50cm agreement between my orthomosiac and my reference points.
With a single GCP at the launch site and then applying a global shift this comes down to sub 25cm.
These results were obtained using photoscan for processing.

Update October 2017
X and Y accuracy now confirmed as sub decimetre with no GCPs, but a good camera calibration.

 

[timmydjr]

I assumed that the use of GCP was already taken into account!

The P4 alone won't give you any survey grade result. The result won't be correctly scaled and the whole plane will be tilted, with the part further away from the beginning of the flight showing -wrongfully- at an higher elevation.

Using GCP solve entirely the problem and you do get easily into the 2 to 3 cm precision mark. This is however linked to the precision of your ground points.

So if you can make use of GCP through a RTK GPS or official points and a total station, there is no need to heavily invest into RTK drones.

Do you have a YT Video on how you set that up? I am just learning drone mapping and RTK stuff. I want to incorporate RTK on my P4 and I2 . Any help will be appreciated.

 

[Spatial Analytics]

Do you have a YT Video on how you set that up? I am just learning drone mapping and RTK stuff. I want to incorporate RTK on my P4 and I2 . Any help will be appreciated.

My method requires a Reach RTK unit and my timing chip, but doesn't require opening up the drone, just strapping it on. I am making small batches of my cradle and chip. PM me if you want more info.

 

[fberna]

My method requires a Reach RTK unit and my timing chip, but doesn't require opening up the drone, just strapping it on. I am making small batches of my cradle and chip. PM me if you want more info.

I am very interested in your method.

How can I contact you? Or could you contact me at [email protected] ?

thanks