DJI Phantom 4RTK

No, but I'm experimenting with an Emlid Reach M+ GNSS mounted on the Phantom 4 using a device made by Tuffwing.?ÿ I'm using my own Trimble base and processing PPK with RTKLIB.?ÿ I had to write some custom software to correct for timing, yaw, pitch, and roll, but results are impressive.?ÿ

Bill68,

1. With RTK the Phantom 4RTK uses NTRIP for corrections, what are you using to the send the RTK corrections between the Base and Drone? This normally requires an internet connection via cell service. I'm testing if a peer-to-peer wifi connection will work from Base to Rover where there is no cell coverage.
2. I have used 1-second epochs, recently I notice others recommended 0.2-second epoch, what EPOCH rate are you using for PPK?

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I've just been post processing and recording at 5Hz.?ÿ I don't see much advantage to maintaining a real time connection.?ÿ Just something else to go wrong.?ÿ?ÿ

Would you care to share your custom software for testing? Contact me offline at lee@leegreen.com if you want.

@leegreen

Hi Lee, did you manage to sort out on how to get the ntrip corrections over the wifi with no cell coverage? Appreciate if you could give some headsup on how to go about it. Feel free to email me at ard.surspec@gmail.com

TIA

I have been using the Phantom 4 RTK with Aeropoints from Propeller.?ÿ The process of attaching the RINEX file and getting adjusted image tags through the propeller platform is quite smooth.?ÿ You can also use a RINEX generated from a standard base station in the propeller platform as well.?ÿ You must start your survey before your flight and end after you have landed otherwise the platform wont apply the adjusted tags.?ÿ Once you have your adjusted PPK tags, depending on what software you use to process your images you will have to determine what workflow best.?ÿ I use Pix4D and have developed a fairly robust workflow to best utilize the adjusted tags.

Any idea of the RTK complete kit? Thank you.

@bill68

What is your workflow for PPK to apply corrected coordinates imbeded back into the images? I REALLY want to pull the trigger on a Phantom 4 RTK versus modify my P4P with an aftermarket RTK system such as BAAM.tech or whatever as it hurts overall flight time. This is the last piece of the puzzle I need to wrap my mind around before I do so. What software do you use for mapping? Pix4d? Photoscan/Metashape?

Im using photoscan and I did find the video below on youtube, but I doubt the program does this entire process. It seems to easy lol.

P.S. I am also worried about DJIs business plan. They seem to be moving away from the phantom series, which makes no sense to me as it seems to be the best option. 

@leegreen

Are you using the BAAM.tech system for PPK? What workflow have you found to work well for you? Shoot me an email Joshw@cswst2.com if you'd prefer to keep it offline as well. 

@surveyorjosh

About six months ago I purchased a Phantom 4 RTK.  Being dual frequency it is more reliable, and is easier to operate than the Phantom 4 Pro with Emlid Reach mounted.  I use my own Trimble R8 base instead of the DJI base, and post process with RTKLIB.  The timing and level arm corrections are applied with software I wrote.  With Pix4d and Agisoft it is not necessary to modify the image coordinates.  Those software allow you to import a csv file of the PPK coordinates.

Over on the Emlid forum there are a few people who have started to test out the ASHOT and TEOKIT as an RTK surveying kit add-on to the P4Pro.

I think they are also using the Emilid M+, however I would love to implement the new dual frequency M2.

@detritalgeo

Ya, same. Do you know of anyone that makes a kit for this?

Tuffwing has a kit for the emlid M+, but the new emlid M2 uses a different antenna.

http://www.tuffwing.com/products/Phantom_Reach_PPK_Integration_kit.html

I am curious why you think the RTK drone has a workflow advantage? Typically you are going to need ground shots on almost any site, so why not set your targets and survey them in the conventional way and then fly the sight.?ÿ Even with an RTK drone I would want at least as many check shots to verify the processed data is accurate and that would require highly visible targets.?ÿ Also, I do not understand the workflow advantage of the Aeropoints over settings targets using a ground based RTK setup.?ÿ?ÿ

Posted by: @gfperry

I am curious why you think the RTK drone has a workflow advantage? Typically you are going to need ground shots on almost any site, so why not set your targets and survey them in the conventional way and then fly the sight.?ÿ Even with an RTK drone I would want at least as many check shots to verify the processed data is accurate and that would require highly visible targets.?ÿ Also, I do not understand the workflow advantage of the Aeropoints over settings targets using a ground based RTK setup.?ÿ?ÿ

You're right it doesn't really have a workflow advantage if you already have access to a total station or survey grade GPS equipment, which most on this site will already have. This is why I still use the P4P and have not purchased the RTK model. For the price of an RTK drone you could pick up a brand new iG8 rover on a network or a static iG4 and do OPUS RS. Im sure theres other reliable cheap recivers out there as well. I honestly think alot of it is the P4P looks like a toy and poeple want a more professional drone, but the matrice 210, inspire 2, etc. would use an zenmuse X4s and wont really out perform the P4p since it is basically the same camera anyway with much more money sunk into it. In my opinion the best thing to do right now is to wait and see what comes out next and keep on keeping on with the P4P. DJI isnt making phantoms anymore besides the RTK model from what I can tell. Prices of parts are going up on ebay now. I heard production is going to come back, but you cant buy anything new anywhere that I can find.?ÿ?ÿ

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@gfperry

I have the BAAM.tech PPK system on my Phantom 4 Pro.  I fly an industrial construction site once a month.  The site has six permanent monuments established by another surveyor that I use as GCPs.  I just lay my targets over them.  To achieve the highest degree of accuracy, I use the six GCPs in addition to the PPK data.  I've processed the data with and without PPK, and even with the six GCPs, the PPK data increases the accuracy of my project.  I collected 25 vertical check points with my robot to assess accuracy.  With the six GCPs plus PPK, the vertical accuracy is 1-1.5x ground sample distance.  Without PPK, the vertical accuracy is 1.5-2x GSD.

So in my experience, the PPK doesn't improve the workflow (it's actually more work to process the PPK data), but it does increase the overall accuracy with the P4Pro.

@andrewm

Hi, Can you help me with setting up the BaamTech base station? This base is a 3d printed base from Baamtech and looks plain. All is has is a red two-way switch on the side but no lights (LEDs).
I understand I need only to set it up outside near the survey area say 10 minutes before flying the drone. There are no indications it is on, or recording a RINEX file.?ÿ
When I examine the re-moveable thumb drive later, there is no file.?ÿ
I believe the drone does not need to be flying during the time the base is collecting timestamped GNSS data.

However in a normal situation the drone will be flying and generating timecoded images that a later joined in the PPK processing (using timecode).

Once I can create a base RINEX file I will go to the next step of flying with DJI and Maps Made Easy etc.?ÿ

Thank you for your advice.?ÿ BaamTech provide sales but the support I need at this time.