Different data from almanacs and Ephemeris

[Cozouf]

Hi everyone,

I'm starting to work on the piksi device and I have tried the NMEA and the SBP protocols.

I'm working with the sbp, I have gathered the Ephemeris from gps and I'm calculating the x, y, z coordinates and llh of each gps. However, I have a lot of difference between my computation and the llh I find on the internet. I have also noticed some data from GPS Ephemeris arent the same than the almanacs data. Like w and m0
Do you have any idea why ?
In addition I use the python library orbital, one of you know if that is saved and checked ?
Thanks