I need some guidance on whether RTK Positioning should be turned off or left on when flying PPK based missions using the D-RTK2 as the base station.


  

This guide states that RTK Positioning should be turned off: https://enterprise-insights.dji.com/blog/ppk-post-processed-kinematics-workflow

  

  

And this guide makes no mention of this step to disable RTK Positioning: https://support.dji.com/help/content?customId=en-us03400004288&spaceId=34&re=US&lang=en&documentType=artical&paperDocType=paper

  


I assume RTK Positioning when talking to a base station (the D-RTK2) should remain on, and not be turned off, and that the first guide is incorrect or out-dated.



Can someone from DJI give a definitive answer on this please :-)

If RTK is on:  the pictures 'll have RTK info, I think you can during PPK processing overwrite those info. So you can keep it on, the blog post is because if you don't have RTK connection then you have to disable RTK otherwise you can't start a mission.
ps: not DJI, nor DJI supplier. Only a humble user :-D

AR_AirPrecision Posted at 12-14 04:18
If RTK is on:  the pictures 'll have RTK info, I think you can during PPK processing overwrite those info. So you can keep it on, the blog post is because if you don't have RTK connection then you have to disable RTK otherwise you can't start a mission.
ps: not DJI, nor DJI supplier. Only a humble user :-D

Hey hi there, thanks for replying!

I'm probably getting this wrong but here goes ... every day is a school day :-)

If I am using the D-RTK2 as a mobile station in broadcast mode (mode 5) then I am in fact using RTK + GNSS. The mobile station is in a known position, and broadcasting RCMP strings (I believe), and the rover is operating relative to it.So you would definitely want the drone to maintain its positioning (RTK Positioning) based on that "RTK" data?

A PPK mission can be flown with or without RTK, if with RTK then its either the D-RTK2 (or equivalent device) or an internet NTRIP server?

I have only known of RTK in the context of a subscription to a CORS provider, to get access to an NTRIP server for the corrections. The D-RTK2 when introduced confuses me re terminology to use.

Hope this makes sense.

Robert Marshall Posted at 12-14 05:38
Hey hi there, thanks for replying!

I'm probably getting this wrong but here goes ... every day is a school day :-)

Hello!

We don't use D-RTK2 but Emlid or NTRIP provider.

There are two overlapping stuff here :
- RTK for UAV positioning
- RTK for "pictures" positioning ( via P1 on M300 as example )

PPK applies to second scenario but you can use 1 and 2 with PPK also.

D-RTK2 mode 5 I'm not aware of what it does but it should indeed propagate corrections to mobile stations or the UAV. Format is not relevant in your question ( I think ).

What exactly is your question based on what I wrote down :-) ?

A PPK mission on M300/P1 ( example ) can be flown with RTK activated if RTK available ( D-RTK, network, custom,... ) or you have to disable RTK as you won't be able to take off or start mission with RTK enabled and without RTK corrections coming in.

AR_AirPrecision Posted at 12-15 00:33
Hello!

We don't use D-RTK2 but Emlid or NTRIP provider.

Yeah that aligns with my view on this but I am a novice and don't want to assume with  DJI software so seek a steer.

So the first guide that says to disable RTK Positioning is incorrect for the setup I have (M300, D-RTK2 in known position and in mode 5), and I wanted to confirm that. Two people have now, yourself and another.

I would like DJI to update their documentation or even create a real documentation library for their products, I use to work heavily with Microsoft software, and their enterprise documentation is a sight to behold compared to what we get from DJI ...

Two interpretations of RTK indeed ... RTK for POS on the images and RTK for POS of the rover, the POS on the rover is going to get touched as part of the PPK process, but you would want the rover to be using RTK to position itself accurately while talking to the D-RTK2.

All this because one guide has a incorrect step listed which is contradicted by another guide by the same company.

I will write a guide to walk through this and put it on my website, ideally it would be better placed in a DJI documentation library and kept current, a documentation library that we can edit\submit changes for, and DJI process them into their documentation. Wishful thinking!

Thanks for the help Captain AR_AirPrecision!!!!

Robert Marshall Posted at 12-15 01:00
Yeah that aligns with my view on this but I am a novice and don't want to assume with  DJI software so seek a steer.

So the first guide that says to disable RTK Positioning is incorrect for the setup I have (M300, D-RTK2 in known position and in mode 5), and I wanted to confirm that. Two people have now, yourself and another.

@LV_Forestry can give you more info as he has extensive knowledge with DRTK2.

The main challenge is the firmware evolves and the accessories around the DJI ecosystem are complex...normally you should get better feedback from your DJI enterprise supplier as they sold you the system and accessories :-)   

Hi there.
1. When using PPK, RTK positioning on the aircraft side can be turned off and does not need to be turned on. D-RTK2 only needs to be turned on normally to collect RTCM ephemeris data. The time for D-RTK2 to collect ephemeris data needs to be longer than the time for the aircraft to collect photos;
2. If D-RTK2 is connected to the aircraft in real-time and uses RTK service, you need to enable RTK positioning on the aircraft side and select D-RTK2 as the service type for connection.
You can refer to the PPK setting guide below. Source: https://enterprise-insights.dji. ... kinematics-workflow

DJI Susan Posted at 12-15 04:49
Hi there.
1. When using PPK, RTK positioning on the aircraft side can be turned off and does not need to be turned on. D-RTK2 only needs to be turned on normally to collect RTCM ephemeris data. The time for D-RTK2 to collect ephemeris data needs to be longer than the time for the aircraft to collect photos;
2. If D-RTK2 is connected to the aircraft in real-time and uses RTK service, you need to enable RTK positioning on the aircraft side and select D-RTK2 as the service type for connection.

That is a definitive answer thank you Susan.

It's the text in that very same screenshot that confuses things, it actually says to disable it, and it was this that had me come here to confirm.

Thank you, and Merry Christmas to you Susan and the others chiming in here.

Robert Marshall Posted at 12-15 06:25
That is a definitive answer thank you Susan.

It's the text in that very same screenshot that confuses things, it actually says to disable it, and it was this that had me come here to confirm.

Thank you for your feedback, and always happy to help. Please feel free to ask if you have further questions.