How to process PPK data with NTRIP corrections

Reach Module / M+ / M2 RTK / PPK configuration
1

I’m trying to process data from a drone mounted Emlid Reach to give me accurate locations of camera triggers - but I’m struggling to get good results. This is what I’m getting:

output1
output11059×725 173 KB

How can I process this data to get better results???

My setup:

  • Fixed wing drone with Pixhawk flight controller
  • Emlid Reach with Tallysman antenna, mounted on the top of the UAV with a 10x10 cm ground plane
  • Camera is a Sony a6000 with a hot shoe feedback cable to the Emlid
  • NTRIP data streamed over LTE mobile connection from a paid service (UK based), base station is ~4km away
  • NTRIP corrections are fed to the drone over the telemetry radio using Mission Planner

My hardware setup follows the guidance in the Reach docs for ArduPilot integration.
I processed the data using Emlid RTKLIB following the instructions in the Reach docs for GPS post-processing.

Can anyone tell me where I’m going wrong?

2

Hi,

In order to find where the problem is, we’ll need logs from Reach rover and the reference station.

Could you also post a photo of your antenna setup?

3

Here is my antenna setup:

drone_antenna
drone_antenna.jpg3264×2448 2.67 MB

And here are the rover and base log files from the Reach module:

raw_201806021318.UBX.zip (2.5 MB)
base_201806021318.RTCM3.zip (200.1 KB)

4

Does anyone have any suggestions??

Is there an NTRIP PPK tutorial or guide available online?

5

Hi,

Apologies for the delayed response!

Thanks for posting logs and fixed-wing photo.

From the rover log a lot of noise can be observed. I’ve got the same results as yours.

logs|290
logs.png779×552 82.3 KB

Please try isolating Reach from noise/interference. You can use aluminum foil to shield the receiver.

6

Hi @dmitriy.ershov thanks for the reply, I really appreciate the help you provide on the forum.

Just a few follow up questions before my next field test:

  • If I reduce the noise/interference will it improve my results, or are there other problems? I.e. is noise my only problem?
  • Do I need to shield only the Reach reciever unit or the antenna and telemetry cables as well?
  • Do you have any examples of good shielding or advice for shielding the unit?

Thanks again!

1 Like
7

If I reduce the noise/interference will it improve my results, or are there other problems? I.e. is noise my only problem?

In the meantime, it seems to be the main problem.

Do I need to shield only the Reach receiver unit or the antenna and telemetry cables as well?

You can start with shielding Reach, antenna cable and the wiring around it.

Do you have any examples of good shielding or advice for shielding the unit?

Could you please make a forum search on this matter? Noisy electronics shielding was discussed on the forum many times.

After you isolate Reach, you can test the drone on the ground and log Reach data for test purposes. Feel free to post new logs here, we’ll take a look!

8

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