Questions about GPS use and configuration

Semi novice trying to learn, hope someone can enlighten me?

I have tried to find information on how Ardupilot utilises GPS data.
My search of WIKI and other sources have been unsuccesful.

I even tried to find the relevant code but failed, a pointer to it would be welcomed.

I have installed GM10 Flywoo GPS’s in three of my Multicopters. I have seen an improvement in the static drift, the snail trail on MP, on the bench and on the ground.

Loiter and Althold appears to be better too but am I imagining an improvement?
Am I right that both use Accel data and GPS are used to maintain location, I’m possibly wrong?

If someone could answer the following I would appreciate it.

Is the data taken, as is, from the GPS or is there further averaging or predictive filtering?

How to configure the options for the best use.

  1. Is it an advantage to have a high number of satellites? With my M10 I am receiving up to 30 navigable and 40 not navigable (from U-center2)! If the high number is excessive should I limit the constellations to the most apparent to lower computation overhead, I am using H743 FCs?

Current GNSS constellations seen are

GPS(G) 7/11

SBAS (S) 0/4

Galileo (E) 7/12

BeliDou (B) 7/13

QZSS (Q) 4/4

Should I leave as seen or select best ?

  1. Is blended a better option when using two GPS’s or Use Best?
  2. Is the HDOP figure used to select the best input?

Thanks for any improvement in my education!

And yes, do limit the number of satelite constelations to at most two in order to keep the update rate as high as possible

amilcarlucas,
I very much appreciate the pointers to answer my questiuons
I’ll take some time to consume the info.
EDIT!
Sorry, Info was right under my nose, how I missed it I don’t know, thanks for the reply.
Thanks and
Regards.