I mean exactly what I wrote: "GPS itself" means GPS, itself.

Not GPS and WAAS. Not GPS and RTK. Not GPS + wifi + BT + cellular. I didn't mean any of those things, so I did not write any of those things.

If the thing is more than GPS -- by itself -- then that's outside the scope of what I was referring to with the juxtaposition of the words "GPS" and "itself".

(If a thing -- by itself -- can be better specified to be that way using concise phrasing, then I'm all ears.)