How to make landing more precise with DGPS?

I had DGPS constantly feeding in position to the mavproxy thru DGPS module at port 13320.

But it seems that the landing is still about 1metre difference. Is there a way to make landing more precise? I assume DGPS can reach centimeter grade precision, why the difference is in at least 1 mettre?

Anyone here tried precise landing using DGPS?

You need to tune the copter to get that level of precision. Did you tune the notch filters? used autotune?

Kindly enlighten me where can I find out more about this?

This forum is full of posts explaining it. Here once again for your convenience:

  • use “Alt-A” in mission planner
  • search for “arducopter dynamic notch filter”
  • search for “arducopter autotune”

Apply the steps in the presented order.

Ok will try autotune later.

I am using mavlink to inject the RTCM.

I now can achieve within 30cm landing without IR-lock.

Anyway in case anyone face the same issue. I realised

  • Using DGPS module in mavproxy, can achieve about 1-1.5metre accuracy when landing.
  • manually inject using mavlink and pymavlink. 30cm.

I think something to do with the RTCM. The position in mission planner kept moving around.

I don’t seems to be able to achieve RTK using mavlink without using mission planner. Still trying to figure out how. Only able to get 3D DGPS.

Also I realised if I turn to manual control example poshold or alti hold, there is a lag between injecting rtcm and injected manual control command making it impossible to control safely. I think its necessarily to turn off the rtcm update when doing manual control.

It works great with auto mode though.