Originally Posted by njkayaker
Talking about units that have to be stationary and use ground-based systems to get accurate data in a discussion about bicycle GPS units make no sense at all.
You posted the link. Not me. And the first article was more than 20 years old, the
newest was more than a
decade old. Things have moved on since then: We now have Galileo,Beidou, and others
in addition to the now very-old "GPS".
As for D-GPS and WAAS. Back then, GPS was SCRAMBLED, so it wasn't as precise as it is now for civil use. So people thought up ways to augment the system to become MORE precise.
In
January 2000 President Clinton signed an order to
descramble the GPS signal, making for a more precise signal directly from the satellites.
That's how old and out-of-date your first reference is.
Originally Posted by
njkayaker
I know. I compared it to doing the same with a hand bearing compass, and since simple concepts seemed to be over your heads, I used simplified language to convey the idea.
Originally Posted by
njkayaker
D-GPS and WAAS aren't "sat systems".
The Garmin watches don't seem to perform any different than the cycling units.
It seems to be difficult to get more-recent info. But I provided something and you provided nothing.
And, even for the latest units, Garmin rates barometric data over GPS data.
D-GPS and WAAS are add-ons to sat systems, and as such they are part of the sat system even if they use land based positioning/relays to augment the system. And it was done as a patch on the SCRAMBLED GPS, because back then it was SCRAMBLED for civilians, making for
much less accuracy.
As for the watch: A barometer is easier, cheaper, and packs into a smaller size than using chips and antennas for Beidou, Glonass, Galileo and so on. THe fact that there is a barometer doesn't mean it is then better at finding your altitude. A barometer is very useful for actually checking the atmospheric pressure and sudden drops in it.
As for me not providng anything: I provided facts and actually explained how the systems work. You provided decades old information that isn't even true of the original system today. Things move on and we get better at technology as time moves on. What you did was akin to providing a medical article that was two decades old and then claiming that things can't possibly have moved on since then. That is not "providing something". That is "fielding old information and presenting it as a current fact".
First you argue that you can't have glonass, galileo etc. in a small cycle computer, and then you go on to argue that a barometer must be better because Garmin watches has a barometer and used one for altitude in 2017.
And this in addition to you posting "support" for the idea that satellite positioning systems cannot be used for altitude. "Support" that in one instance was 20 years old (which even mentioned surveying equipment which was VERY precise), and an article that was a decade old.
Constantly moving the goal posts as you constantly do is not a good look.