Jump to content

GPS EPE confidence


g.bartoli
 Share

Recommended Posts

Dear TinkerForge,

We recently bought a GPS Bricklet unit and we would like to have some more details about the data received in the callbacks.

 

We successfully used the coordinate callback as explained here: https://www.tinkerforge.com/en/doc/Software/Bricklets/GPS_Bricklet_C.html#c-c-gps-bricklet

The data contains also the EPE value which we read about here: https://www.nps.gov/gis/gps/WhatisEPE.html

What we did not understand is which confidence interval is used: 50%, 68%, 95%, 99.7?

 

We need this information to calculate the position covariance (standard deviation) following this approach: https://en.wikipedia.org/wiki/Standard_deviation#Rules_for_normally_distributed_data

 

Many thanks,

Guido

Link to comment
Share on other sites

Ok, looking through the Datasheet by myself, maybe I found it at page 16: https://github.com/Tinkerforge/gps-bricklet/raw/master/datasheets/FGPMMOPA6H.pdf

 

Position Accuracy Without aid:3.0m (50% CEP)

DGPS(SBAS(WAAS,EGNOS,MSAS)):2.5m (50% CEP)

 

But I do not know how to relate this fixed CEP specification (which seems the best case) with the variable EPE measurement coming from the GPS Bricklet (often I receive about 1.3m, which is surprisingly low)... can I consider them equivalent measures? ???

Link to comment
Share on other sites

  • 3 weeks later...

Based on your question about getting covariance values for the GPS errors, it sounds like you are working on a Kalman filter to fuse GPS and IMU data.  Is this the case?  I am interested in the same thing but need someone to talk to about the actual kalman filter implementation.  If you are working on the kalman filter I'd like to converse with you.  My email is andycruce@comcast.net.

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...