Hi all,
I have DJI P4M and connected to D-RTK unit. You know that P4M only process 99 way points and save them seperatly (also that happens when you swap batteries during the mission), but it doesn't continue numbering from where it stopped, instead it starts from the beginning so images in each file are named the same. Also, the D-RTK unit produce 4 files (EVENTLOG.bin, PPKRAW.bin, Rinex.obs, and Timestamp.MRK) for each folder created by P4M. When processing the iamges using any software, you have to put all the images in one folder in order to get one orthomosaic iamge of your study region, but when you do that, the D-RTK files will be only used for the images that matches the names inside these files. How I can overcome this issue? I tried to develop a code to rename the images, and afterthat I renamed the colmn in the *.MRK files and merged all MRK files into a single one, but I couldn't open the other three files, so I don't know if dealing with the MRK files is enough to process all the images.
I tried my best to clarify my issue, so I hope it make sense and you will be able to help me fix the problem.

The exif of the images contain the corrected coordinates and the precisions on the 3 axes.  
The DRTK does not generate any files in the drone.  
The OBS file is specific to the drone.  
If you have placed the DRTK 2 on a known landmark and entered the coordinates in the app, then there is nothing more to do.

LV_Forestry Posted at 7-17 12:02
The exif of the images contain the corrected coordinates and the precisions on the 3 axes.  
The DRTK does not generate any files in the drone.  
The OBS file is specific to the drone.  

Thanks! So what's the purpose of the three other files (the 2 .bin files and the .MRK file)?
I actually do not enter any coordinates, I just connect the D-RTK2 unit to the drone and make sure its connected, then start the mission. I use the "DJI GS Pro" app on the mini iPad.

tareqkun Posted at 7-17 12:19
Thanks! So what's the purpose of the three other files (the 2 .bin files and the .MRK file)?
I actually do not enter any coordinates, I just connect the D-RTK2 unit to the drone and make sure its connected, then start the mission. I use the "DJI GS Pro" app on the mini iPad.

They are useful to do PPK.  
If you are using the DRTK 2 without entering precise coordinate, then the coordinates will most likely be random, very useless.

LV_Forestry Posted at 7-17 12:23
They are useful to do PPK.  
If you are using the DRTK 2 without entering precise coordinate, then the coordinates will most likely be random, very useless.

Interesting! Thank you so much! Are you aware of a tutorial or manual on how to enter the coordinates in the app that you can share it with me?

I think what LV_Forestry could have said was that without entering precise XYZ coordinates for the location of the D-RTK 2, the corrections it provides to the P4M are helpful to provide internal consistency of image positions but will not yield real-world accuracy much better than 1-2 m (assuming you do not move the D-RTK 2 for the duration of all flights). This is beacuse the base (D-RTK 2) must know its precise location in order to generate corrections for the drone (P4M) with real-world accuracy.
See this(and other web explanations of How RTK Works).

There are lots of tuitorials and videos for using the D-RTK 2 with the P4RTK & P4M. Just Google them. The basic idea is that you need a benchmark (your own or somebody else's) at your site for which you have precisely known coordinates in Lat/Lon decimal degrees and Height Above Ellipsoid (HAE). You enter them into the RTK section of the flight software (including the antenna offset above the mark due to the tripod pole). It's very simple.

But you really should understand what you are doing before you just go off and use gear like this, if you expect it to perform as advertised.

patiam Posted at 7-20 07:15
I think what LV_Forestry could have said was that without entering precise XYZ coordinates for the location of the D-RTK 2, the corrections it provides to the P4M are helpful to provide internal consistency of image positions but will not yield real-world accuracy much better than 1-2 m (assuming you do not move the D-RTK 2 for the duration of all flights). This is beacuse the base (D-RTK 2) must know its precise location in order to generate corrections for the drone (P4M) with real-world accuracy.
See this(and other web explanations of How RTK Works).

Thanks patiam, your thorough explanation is really helpful!  I am new to the world of drones, and gladly I am learning new things every day, I learn the most from my mistakes (although I wish I was born with this knowledge already! ) and from the help I get from experts like you who are willing to share their knowledge and experience. For some reason (maybe influenced by the seller) I thought the D-RTK2 already knows where it is located, just like a GPS, thus there is no need to any user input, and it communicates with the RTK on the drone to tell it where it is, not only in relation to the ground station, but also on the globe. Thank you again, that's is extremely helpful, and I will do this in my next mission in few days.  

tareqkun Posted at 7-20 07:48
Thanks patiam, your thorough explanation is really helpful!  I am new to the world of drones, and gladly I am learning new things every day, I learn the most from my mistakes (although I wish I was born with this knowledge already! ) and from the help I get from experts like you who are willing to share their knowledge and experience. For some reason (maybe influenced by the seller) I thought the D-RTK2 already knows where it is located, just like a GPS, thus there is no need to any user input, and it communicates with the RTK on the drone to tell it where it is, not only in relation to the ground station, but also on the globe. Thank you again, that's is extremely helpful, and I will do this in my next mission in few days.

You're very welcome.
Drones are already a learning curve w/o adding precision GNSS into the mix, so good luck!

To calirify- the D-RTK does know where it is, as it is a GNSS unit- it just doesn't know precisely enough to generate corrections for the drone that will be survey-grade accurate unless you tell it, or provide corrections to it from another source. The concept is Differential Correction. The base station compares its independently computed position to the precisely known one you have provided it, and determines the difference (offset) in XY&Z, and send that to the drone. Without the precisely known position, the base has nothing to compare to, so the corrections it sends are not as good.