Neo-M8 and magnetic declination

0 votes
The NEO - M8 receiver supports message UBX NAV-PVT which reports amongs others, a magnetic declination and magnetic declination accuracy.

Can you put more more light on where do those data come from? Are they SW estimated by the standalone receiver, or is there are any actual and up-to-date Earth's magnetic field mesh state part of broadcasted satellite information, or anything else?
by achary asked Mar 7, 2017
0 votes
by clive1 answered Mar 7, 2017
The document I'm reffering to is "u-blox 8 / u-blox M8 Addendum to Protocol Specification
for HPG 1.30" from

Table continued on page 48 of the PDF, byte offsets 88 and 90 respectively
0 votes
HPG addendum section 3.2.4 p19 magnetic parameters "not supported".  
I suspect they forgot that disclaimer note for NAV-PVT detail.
From what I recall from older (and other mfr.) GPS receivers, the magnetic correction table consumed a lot of memory and needed frequent updates otherwise it would be too misleading.
by grampy answered Mar 8, 2017
by grampy edited Mar 8, 2017