Just got this from DJI Support. It appears to be a new draft or in-house manual documenting the use and functions of the D RTK-2, with previously un-documented methods and functionality (including "Mode 3" AKA handheld mapping use! requires the MG app).


This is clearly a pre-release version and not even available on https://www.dji.com/d-rtk-2/info#downloads yet.

Enjoy!

Wow!  good find!

Just tried the Mode 3 thing and couldn't get it to link to RC after switching modes. Ran out of time, I'll try again later.

Thanks for sharing

Hi, good day patiam. Thanks for sharing this information to our DJI co-pilots here in the Forum, Thank you for continued support and have a wonderful day!

patiam Posted at 5-1 13:08
Just tried the Mode 3 thing and couldn't get it to link to RC after switching modes. Ran out of time, I'll try again later.

Hi patiam,

following the instructions of the draft D-RTK 2 user manual you have shared with us, after setting the D-RTK2 in mode 3, I have been able to start a "Walk with handheld RTK" session in the DJI GS RTK app. Moreover I was able to save some point coordinates.

The point now is that I am not able to find the saved data file, both in P4RTK Remote Controller and in the D-RTK2 receiver. I suppose I have to look for it into the Remote Controller internal memory or into the SD card, but I do not know how to list the memory content.
Do you have any suggestion?

Moreover, did you manage to save and dowload any RAW data (RINEX) from the D-RTK2 ?

Thanks,
Maurizio

P.S.
I have installed last firmware version (v02.02.0014).

Nice.  Thanks Patiam

Hi,


from what I read, it seams that the D-RTK2 Mobile Station stores the raw GNSS data (satellite observation and broadcast ephemeris ??) into RTKnnn.DAT files.  

You can find them into the following directories:
\log\rtcmraw (read the D-RTK2 internal memory as an USB storage device)
log_export (use DJI Assistant 2 for Phantom > Log Export)

The files should be in RTCM3.2 MSM5 binary format and it should be possible to convert them in RINEX format using a thrird-party tool.

I have found such info in the following document:  https://shop.quadrocopter.com/assets/images/P4RwhitePaperV2.pdf

I will furder investigate the topic and let you know.

Maurizio

Hi, i find a way to convert the DAT file to RINEX.
Follow the next tutorial from Emlid:

https://docs.emlid.com/reach/common/tutorials/gps-post-processing/

mbuonanno Posted at 11-15 08:40
Hi,

Wow Maurizio that document is a treasure trove! Thank you for sharing!

tutos Posted at 11-15 08:58
Hi, i find a way to convert the DAT file to RINEX.
Follow the next tutorial from Emlid:

Hi,

thanks a lot for sharing the link.

I agree that the best free tool for data format conversion and pos-processing are RTKlib and RTKlib demo5.

You can find useful materials in the following  web sites too:
http://rtkexplorer.com/
https://www.aerotas.com/phantom-4-rtk-ppk-processing-workflow/

I did not opened the D-RTK2 Mobile Station but I suspect that its GNSS chipset is an u-blox ZED-F9.

Maurizio

Hi patiam,

news about using the D-RTK2 Mobile Station in Mode 3  (i.e. Handheld Mapping Device or RTK Rover).

Eric Wischropp (2019) published a detailed “DJI DRTK 2 Rover Guide” for using the D-RTK2 in Mode 3  (“Walk with handheld RTK" operation mode) while receiving the NRTK corrections from the 4G dongle mounted in the P4RTK Remote Controller. His instructions are reported below.

1) The base / rover must be in rover mode. This is accomplished by pushing the right button until the adjacent light flashes in 3 pulses. If it flashes in a single pulse, it’s in base station mode #1 for use with the drone. If it flashes in two pulses, it’s in mode two which is not enabled currently.
2) Turn on the base and remote controller and allow them to initialize.
3) Check to see that WIFI is on and connected to a source with good working internet.
4) On the remote controller’s main screen, tap on the 3 lines at the upper left to enter the left settings slide out tab / box.
5) Tap on the drone icon and you’ll open the “Device Management” screen.
6) Click on the “Handheld Stick + Walk with Network RTK” option. All options may look greyed out but should work anyway when you choose one.
7) Then click on the green Linking button / box.
8) Then click on OK and then OK again on the next screen.
9) The instructions tell you to make sure the device is powered on. Since we powered it on earlier, you can just confirm that the base / rover is powered on.
10) Proceed to the next step.
11) This step ensures that the receiver is in mode #3 that was discussed in step #1 above
12) Once this is certain, press the green button and proceed.
13) Make sure the left hand light on the receiver is blinking green and red to indicate it’s in linking mode. If it is not in that mode, tap on it until it blinks red and green.
14) Proceed and the remote will beep while it links with the “rover”.
15) You will see “Linking Successful. Restarting device.” when done. Click on “Done” and then “Close”. Now tap on the background screen to close out the slide out tab / window.

1) Now tap on the “Plan/Fly” button. Tap on the “Plan” side.
2) Then tap on “Walk with handheld RTK” button.
3) You will likely need to tap on the 3 dots in the upper right side of the screen to enable RTK.
4) Tap on the RTK setting option.
5) Turn on RTK and choose the “Custom network RTK” dropdown option.
6) Confirm that your NTRIP server credentials are properly entered.
7) Click on the green “Connect” button.
8) Exit the settings window and return to the measurement window.
9) Confirm that you have RTK accuracy of acceptable error level. If accuracy level is good, you can proceed to measure points.

10) To measure a point, press the set point button.
11) Give the point an appropriate name and description if needed. Confirm that the device height is correctly set at 1.8011 meters.
12) When done recording points, you can save the file and give it a unique name.
13) To access the saved data, you start from the main screen.
14) Tap on the 3 lines at the top left and then tap on the SD Card icon at the lower left side.
15) Choose the dropdown “Export Handheld DRTK Point Task”.
16) This will export it to the SD card inserted into the remote controller.
17) It will export he file to the /DJI/EXPORT/RTK_SCOUT/ directory.
18) Open the desired exported file and manually copy the relevant measurement values and descriptions to a separate text file.
19) If you are adventurous, you can try to automate the process by extracting the relevant data fields automatically in Microsoft Excel or some other software program.
20) I tried storing points with both 1.8011m pole height as well as 0 pole height. Changing this setting on the point storage dialog box did not change the elevation value at all. The point that is stored is the antenna reference point. This is a point inside the GPS receiver head.
21) To reference the point at the lower tip of the rover pole, you need to subtract 1.8011 meters from the value that was stored.


In addition to Wischropp's guide, you can have a look at these two Youtube videos by Arkansas Drone Solutions :

2020 - Arkansas Drone Solutions - Phantom 4 RTK (D-RTK2 Base Station) marking points


2020 - Arkansas Drone Solutions - Using Phantom 4 RTK BaseStation to mark points



Cheers,
Maurizio

mbuonanno Posted at 4-9 13:00
Hi patiam,

news about using the D-RTK2 Mobile Station in Mode 3  (i.e. Handheld Mapping Device or RTK Rover).

Thanks for posting that here, Maurizio!

Ciao

mbuonanno Posted at 4-9 13:00
Hi patiam,

news about using the D-RTK2 Mobile Station in Mode 3  (i.e. Handheld Mapping Device or RTK Rover).

To mbuonanno point at the end of his post I have done some testing but everyone feel free to do there own testing to confirm but when in mode 1 (base mode) you do not subtract the 1.8011m from the ground control point as it seems to be calculated into the point already. I am running the latest firmware in the remote, RTK-2 and the Phantom 4 RTK just FYI so I’m not sure if it’s the same in older firmware versions. In mode 3 (rover mode) you must subtract the pole/antenna height. Again I would encourage others to comment on this as I am no expert and would like this to be confirmed. Thanks to everyone who’s input has pushed this system along in a positive way.

StraightArrow10 Posted at 4-9 13:44
To mbuonanno point at the end of his post I have done some testing but everyone feel free to do there own testing to confirm but when in mode 1 (base mode) you do not subtract the 1.8011m from the ground control point as it seems to be calculated into the point already. I am running the latest firmware in the remote, RTK-2 and the Phantom 4 RTK just FYI so I’m not sure if it’s the same in older firmware versions. In mode 3 (rover mode) you must subtract the pole/antenna height. Again I would encourage others to comment on this as I am no expert and would like this to be confirmed. Thanks to everyone who’s input has pushed this system along in a positive way.

Hi StraightArrow10,

I agree with you. Following the instruction from Eric Wischropp and Arkansas Drone Solutions, when you survey a point in Mode 3 you get the Z (Altitude for DJI, but actually Height above the ellipsoid) of the antenna phase center.

Consequently, when you need the position of a reference point on the ground (i.e. at the pole tip) you have to subtract the antenna height on the ground (1.8011 according to DJI default value), otherwise you will not correct the Z  (e.g. when you want to input centimetric-level coordinates for D-RTK in Mode 1) .

Cheers,
Maurizio

StraightArrow10 Posted at 4-9 13:44
To mbuonanno point at the end of his post I have done some testing but everyone feel free to do there own testing to confirm but when in mode 1 (base mode) you do not subtract the 1.8011m from the ground control point as it seems to be calculated into the point already. I am running the latest firmware in the remote, RTK-2 and the Phantom 4 RTK just FYI so I’m not sure if it’s the same in older firmware versions. In mode 3 (rover mode) you must subtract the pole/antenna height. Again I would encourage others to comment on this as I am no expert and would like this to be confirmed. Thanks to everyone who’s input has pushed this system along in a positive way.

To clarify what I think both @Straightarrow & @mbuonanno are saying, no matter what mode you use, the D-RTK 2 initially calculates the X,Y,Z of the antenna phase center (APC).

If in Mode 1, and you are entering a known coordinate into the UI  for the benchmark over which you have placed the base, you must ADD the height of the APC on its pole to that of the benchmark Z on the ground before entering it.

If in Mode 1 and you are using the XYZ solution of the D-RTK 2 for your base location rather than entering your own known value, the default APC height is subtracted from the initial Z solution by the software before reporting and use in the survey. THIS MEANS IF YOU ARE NOT USING THE OEM ANTENNA POLE THE Z WILL LIKELY BE INCORRECT (you will need to account for the difference between your pole and OEM).

If in Mode 3, the software reports the Z of the APC. To get the ground Z you must SUBTRACT the APC height from the reported Z.

Cheers, everyone stay healthy!

patiam Posted at 4-13 08:41
To clarify what I think both @Straightarrow & @mbuonanno are saying, no matter what mode you use, the D-RTK 2 initially calculates the X,Y,Z of the antenna phase center (APC).

If in Mode 1, and you are entering a known coordinate into the UI  for the benchmark over which you have placed the base, you must ADD the height of the APC on its pole to that of the benchmark Z on the ground before entering it.

Hi patiam,

We all agree that "no matter what mode you use, the D-RTK 2 initially calculates the X,Y,Z of the antenna phase center (APC)".

As far as I know, at present the D-RTK2 in Mode 1 calculates the APC coordinates using a Code-based pseudorange solution (single Point Positioning - SPP)(RTK differential is available in Mode 3 only). The system averages the solutions for about 50 seconds and then freezes the position on the calculated average.

e.g. (from a user_log .DAT file)
bestpos:0,0ms,type:0,lat:0.000000000,lon:0.000000000,hgt:0.000,std(0.000000,0.000000,0.000000)
bestpos:2082,133858200ms,type:16,lat:40.838071183,lon:14.364137186,hgt:193.776,std(1.469309,1.049694,2.386449)
bestpos:2082,133858400ms,type:16,lat:40.838057752,lon:14.364110893,hgt:198.016,std(2.146445,1.552083,3.531028)
bestpos:2082,133858600ms,type:16,lat:40.838057940,lon:14.364110973,hgt:197.990,std(2.146502,1.552072,3.530988)
bestpos:2082,133858800ms,type:16,lat:40.838056888,lon:14.364110778,hgt:197.986,std(2.109553,1.552364,3.531375)
bestpos:2082,133859000ms,type:16,lat:40.838057086,lon:14.364110868,hgt:197.997,std(2.109610,1.552353,3.531334)
...
bestpos:2082,133907600ms,type:16,lat:40.838053817,lon:14.364128558,hgt:196.076,std(1.658283,1.278527,2.777866)
bestpos:2082,133907800ms,type:16,lat:40.838053803,lon:14.364128663,hgt:196.058,std(1.652255,1.256276,2.755571)
bestpos:2082,133908000ms,type:16,lat:40.838053810,lon:14.364128752,hgt:196.040,std(1.650643,1.255451,2.749521)
bestpos:2082,133908200ms,type:16,lat:40.838053814,lon:14.364128844,hgt:196.024,std(1.650670,1.255441,2.749503)
... then after 50sec it calculate the average solution
bestpos:2082,133908400ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133908600ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133908800ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133909000ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133909200ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133909400ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133909600ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)
bestpos:2082,133909800ms,type:1,lat:40.838053603,lon:14.364117239,hgt:197.287,std(0.000000,0.000000,0.000000)

Why the software in Mode1 should subtract the default APC height of the BASE receiver from the initial Z solution before reporting and use in the survey?

I am not a professional surveyor and I thought that for differential calculation it is essential to know the coordinates of the BASE receiver APC, no matter the height of the APC on the ground.

Is it another "strange" decision of the DJI engineers?  Did you check such behaviour of the software?
Please help me to better understand your sentence.  :-)

Cheers,
Maurizio

mbuonanno Posted at 4-14 00:10
Hi patiam,

We all agree that "no matter what mode you use, the D-RTK 2 initially calculates the X,Y,Z of the antenna phase center (APC)".

Ciao Maurizio-

My apologies. The statement I made regarding Mode 1 behavior in standalone (no user-entered benchmark coordinates or NTRIP connection) was an attempted summary/paraphrase of @Straightarrow's remarks. I do not use the D-RTK 2 in this way so have not verified the behavior described. I took his description at face value (and the fact that you did not contest it) and assumed it was correct. Ironically, in my attempts to clarify I have muddied the waters further. Sorry about that.

It did seem weird that DJI would hard-wire the antenna height accounting in mode 1 standalone, but they've made other decisions in the software and elsewhere that are decidedly not survey industry-standard, so the claim couldn't be dismissed outright.

I've chided others on this forum for posting answers to questions when they do not have experience with the kit- and here I've disregarded my own advice. This time I'm the proverbial (and hypocritical) pot that called the kettle black.

Stay safe & be healthy everyone!

Ciao.

patiam Posted at 4-14 07:11
Ciao Maurizio-

My apologies. The statement I made regarding Mode 1 behavior in standalone (no user-entered benchmark coordinates or NTRIP connection) was an attempted summary/paraphrase of @Straightarrow's remarks. I do not use the D-RTK 2 in this way so have not verified the behavior described. I took his description at face value (and the fact that you did not contest it) and assumed it was correct. Ironically, in my attempts to clarify I have muddied the waters further. Sorry about that.

Ciao patiam,

thank you for your clarification. I was a bit "disoriented" by your previous sentence about Mode 1, because I know you are an expert surveyor.   :-)

I  think I missed or I did misunderstand Straightarrow's frase "you do not subtract the 1.8011m from the ground control point as it seems to be calculated into the point already".

A presto,
Maurizio

mbuonanno Posted at 4-14 13:52
Ciao patiam,

thank you for your clarification. I was a bit "disoriented" by your previous sentence about Mode 1, because I know you are an expert surveyor.   :-)

Ciao Maurizio-

Grazie mille for the kind words... I don't know about "expert", but I have been fiddling with this sort of stuff for a while.

I'm glad we are building a community here that can help each other try to make sense out of DJI's sometimes puzzling systems!

Ciao,
-pat

Ciao patiam,

I have written the first draft of what I called "D-RTK2 - User Notes", because actually it originates from the inputs of all DJI Phantom 4 RTK users.

I hope users will read it and send me corrections and comments to improve it.

Next step is to write the "appendix" of the Phantom 4 RTK User Guide.  :-)

Stay safe and possibly at home  :-)

A presto,
Maurizio

P.S.
The system do not allow me to upload the file and shows a SERVER I/O ERROR message. Any suggestion to solve the problem?

This is just another uploading test.

mbuonanno Posted at 4-17 09:09
Ciao patiam,

I have written the first draft of what I called "D-RTK2 - User Notes", because actually it originates from the inputs of all DJI Phantom 4 RTK users.

Ciao Maurizio-

Grazie! I can host on Google Drive if needed. PM me for email address.

Ciao,
-pat

Here the "D-RTK2 User Notes":   https://drive.google.com/open?id ... blZTPUaDijB3n7WZ0RH

mbuonanno Posted at 4-17 09:35
Here the "D-RTK2 User Notes".

https://drive.google.com/open?id=1RzZMxhR3kMtyxblZTPUaDijB3n7WZ0RH

Bello! Lo leggerò...

Hi,  

I suggest to read the folowing thread:

DJI Forum > Pro Systems > PS Software  
New D-RTK 2 For Matrice Series Released Note (05/14/2020)
https://forum.dji.com/forum.php?mod=viewthread&tid=215228

Enjoy the reading,
Maurizio

mbuonanno Posted at 5-16 00:37
Hi,  

I suggest to read the folowing thread:

Ciao Maurizio-

Grazie!

-patiam

mbuonanno Posted at 5-16 00:37
Hi,  

I suggest to read the folowing thread:

any improvement for the phantom 4 rtk?

Guille_Meinero Posted at 5-17 12:31
any improvement for the phantom 4 rtk?

... and now  new "D-RTK 2 High Precision GNSS Mobile Station User Guide" (v.2.0) .

Hi,
Do you know how to use DRTK-2 in mode 3 without the P4RTK remote ? I have two M210 V2 RTK with two DRTK-2. I am really interested by "mode 3" but I don't have the GS app or in my crystal sky remotes. Thank you

IPGP Posted at 9-18 06:56
Hi,
Do you know how to use DRTK-2 in mode 3 without the P4RTK remote ? I have two M210 V2 RTK with two DRTK-2. I am really interested by "mode 3" but I don't have the GS app or in my crystal sky remotes. Thank you

Very good question. I'm interested as well.

patiam Posted at 9-18 07:26
Very good question. I'm interested as well.

Some responses from DJI
"mode 3 of the D-RTK 2 cannot work with M210 V2 RTK. To use this mode, Phantom 4 RTK, T20, T16, or MG-1P RTK drone is required."

After viewing this video   I ask
"Do we also need to have the PH4 RTK  on-site and powered ?"
DJI Answer
" There is no need to use a drone. The relevant remote controller, the D-RTK 2, and the network are enough. Those points are saved in the remote controller in json format which can be exported. The path is remote controller SD card/DJI/EXPORT/RTK_SCOUT/."

So we are thinking about buying a P4 RTK remote controler to do Handheld Mapping with our two DRTK-2

From our DJI dealer :

- It is not yet possible to buy PHR RTK remote only.
- Soon there will be only "one"  D-RTK 2 instead of D-RTK 2 Matrice 210 RTK and D-RTK 2 PH4 RTK. Right now, only D-RTK 2 PH4 RTK could be used with PH4 RTK remote to do "Mode 3" AKA handheld mapping. Not D-RTK 2 Matrice 210  

Is there any method for importing known coordinates into D-RTK2 point list from a *.csv file instead of typing?

Great feed! Thanks guys.
In my (limited) experience with the D-RTK2 and the P4-RTK (SDK) with GS-PRO on iPad...
MODE 1 seems to include compensation for the antenna height.
I say this because I measured the tip location to sub-centimetre using a Leica GNSS-RTK (WGS84 lat long + height above ellipsoid) and entered the tip location into the DRTK2 as the DRTK2 location, and then measured a number of other ground-control points using the Leica.
The resulting images seemed to be centimetres accurate, and definitely didn't have 1.8m of Z-error.
Comments?

tom@abovesurveying.com Posted at 2-23 15:55
Great feed! Thanks guys.
In my (limited) experience with the D-RTK2 and the P4-RTK (SDK) with GS-PRO on iPad...
MODE 1 seems to include compensation for the antenna height.

@tom-

Interesting- that would be contrary to the experience of pretty much everyone else here, albeit most are using GS-RTK on the "stock" RC, not GS-Pro on the SDK RC/iPad...

But then again how very like DJI to have different operating procedures for two different apps to do the same function.

Can anybody else confirm?

Of course, if true, and one is using anything other than the stock pole setup on their D-RTK 2, then one would need to add in the difference between their custom antenna height and the stock DJI one... (Unless the antenna height value is stored somewhere and can be altered).

I'm also waiting to DJI release the Handheld Mapper functionality to a mobile app to use the D-RTK 2 station as a rover with an iPhone only or at least using an iPad connected to the RC.

JPAbdalla Posted at 3-25 09:34
I'm also waiting to DJI release the Handheld Mapper functionality to a mobile app to use the D-RTK 2 station as a rover with an iPhone only or at least using an iPad connected to the RC.

Welcome to the fray, and to those of us waiting for this functionality after over 2 years!

DJI just released this video on their Enterprise channel about setup for M300... I already commented there about the lack of the handheld functionality.

https://www.youtube.com/watch?v=-pzmpmiD9fs

It's strange all this time to release this feature, because in some official resellers sites in Australia and others countries they list the "Mobile Phone Holder" accessory IN THE BOX.

My P4M + DRKT2 combo didn't come with it... just an empty place where it should be.

JPAbdalla Posted at 3-25 10:32
DJI just released this video on their Enterprise channel about setup for M300... I already commented there about the lack of the handheld functionality.

https://www.youtube.com/watch?v=-pzmpmiD9fs

Don't remember if ours had one for sure, but I think so... And that was way back when the P4 RTK first hit the market.

We'll be buying another soon I think, and will see if it comes with one.

Not that there's much use for it...