Inaccurate velocity measurement of UBlox GPS

Hi All:

    During my ground tests, I found that the velocity measurement (in North-East-Down format) of UBlox GPS is not accurate as I expected. The experiment is like this:

    1. fix a UBlox GPS unit on a trolley, which is initially stationery;

    2. move the trolley forward with a relatively constant speed (about 1 m/s);

    3. Stop and check data.

 

    I found that the recorded velocity is liked a bounded but random signal, osillating in the range of -1~1 m/s (yes, I observed even the -1 value at some points). May I know that have you guys encounter a similar problem, and how did you solve it?

 

    If possible, can someone tell me how about the accuracy of the MediaTek GPS's velocity measurement. I roughly remember that it only gives course velocity. If so, based on the measured Euler angles, can I have the North-East-Down velocity vectors?

 

   Many thanks for the help and suggestions from all of you!!

 

Alex

 

   

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Replies

  • 3D Robotics
    I think the uBlox firmware is optimized for much higher speed. Try again in a car.
  • No one has ever encountered the similar problem before!?

     

    Many thanks for sharing some experience!

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