3D dgps vs RTK Fix in a Pixhawk 1 & Here+ setup

ArduCopter Copter 3.5
1

Hi guys,

I have the following setup:

  • Pixhawk 1 running Copter 3.5.3
  • Here+ Rover module connected to the GPS port
  • 3DR module connected to Serial 4/5 port and I2C port

With the following params:

  • SERIAL3_PROTOCOL = 5
  • SERIAL4_PROTOCOL = -1
  • GPS_TYPE = 1
  • GPS_TYPE2 = 0

I guaranted that I am having a single GPS reading (from the Here +) and a single external compass (from the 3DR ublock).

Now, with the Base GPS module, I am getting one of these status:

  • 3D FIX, when the base gps is NOT connected
  • 3D DGPS, when the base gps is connected and green

So as you can see, to have the base connected means 3D DGPS status. However… why I am not able to get RTK FIX? What is the difference between 3D DGPS and RTK FIX status?

Thanks in advance,

JM

2

RTK fix is the real deal (2cm precision)
Everything else is not as good :slight_smile:

3

Related thread -

https://discuss.ardupilot.org/t/gps-status-4-in-3dr-ublox-gps-how-is-it-differential-gps/14507

4

so , you ment after getting RTK fix massage it means 2cm precision …

1 Like
5

Typicaly yes, if the base station is close enough. If not it degrades aprox 1 cm per 10Km distance to the base station.
Just google RTK GPS and you will get lots more information.

1 Like
6

did you solved the issue?

I’m having same problem
I waited 4 hours and can’t get in to RTK lock

7

me neither… looking for some info

8

I have same problem but, I solve.
Moving drone with connect missionplanner.
But I don’t know why rtk fix…