How WAAS Works | Wide Area Augmentation System | GPS Navigation

The Wide Area Augmentation System (WAAS) computes errors from GPS satellite position fixes, and transmits the error corrections to receivers on board our aircraft. If equipped with a WAAS receiver, our aircraft can benefit from far more accurate position fixes, allowing us to fly certain GPS approaches the same as we would a precision ILS.

[allen]

Thank you. That WAAS very informative.

[Vontai]

You saving lives out here. Im trying to learn how to explain this for a checkride and this helped so much

[OKCMark]

Very accurate description of WAAS details. It also provides Integrity, part of which translates to a six second time to alarm for detecting GPS anomalies and notifying your avionics.

[mgtowacademy]

Reviewing for my stage 2 instrument check at a 141. Thank you for your great videos!

[johnfitzpatrick]

Thank you for explaining the GPS and WAAS satellites. I wondered what WAAS was when NAV systems were being promoted in panels.
Merry Christmas and great aviation educational material.
🌟
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[Golfpro]

By far the best explanation I’ve seen! Thank you!

[Muonium]

The WAAS satellites transmit with a power of about 60 watts at a distance of 22, 200 miles in geostationary orbit. That means once the signal reaches earth's surface it's around -160dBm, or 1x10^-19 watts, or about 100 zeptowatts - about the power needed to raise a grain of salt one nanometer....once per day.

[gagesadventures]

Thank you!! This and your RAIM video have helped me tremendously.

[boeingpilot]

Very good description of WAAS. Thank you.

[pilotinaD]

Amazing video, great explanation. Thank you!

[kenneththomas]

Do you happen to have a reference on what happens once the corrections get to the master station?

[PilotJames]

Do reference stations receive information from aircraft as well or just satellites?

[natashashvetz]

And if the baboons stopped using speed c to try to confirm Relativity and use the speed of light in the air, the error would decrease even more.

[zachbrenner]

Oh, so waas is basically RTK over a satellite link rather than a local radio link

[phillipdeckard]

Can you please explain how this works on a flat earth?

[fog]

Smartphone User: My Smartphone says we're at this point on this map, plus or minus 10 feet. We're somewhere within this 20 foot circle.

Me: That 10 foot number is precision of the estimate, not accuracy. In other words, it's a measure of the variation in the location readings it's getting as we're standing here. Not sure if it's the standard deviation of the location readings it's getting or the standard error of the mean of those.


Smartphone User: No, it's the accuracy. It's telling me that the location shown on the map is within 10 feet of my actual location.

Me: So then, it knows your actual location, huh?

Smartphone User: It knows it's somewhere inside this circle.

Me: How does it know that? Wouldn't it have to know your actual location to tell you how far off it is from where the map is showing you?

Smartphone User: Uh, I guess.

Me: Then if it knows your actual location, why doesn't it just show your actual location?

Smartphone User: Well, look! It shows we're right here on this aerial photo. It's lining us up on the aerial photo.

Me: Hmmm. Okay. How does it know where to position the photo on your screen?

Smartphone User: It gets the photos from Google and puts them on the screen where they're supposed to be. The aerial photos are positioned accurately.

Me: Hmmm. Okay. Hey look at your screen now. It's telling us that while we've been standing right here all along, we've actually moved from this side of the street to the other side, even though we haven't moved.

Me: Your smartphone is going to be pretty accurate with the improved technology these days, and it's picking up lots of satellites. But unless has the hardware, firmware and software to receive and real-time correct data from something like WAAS, it can't really tell you its accuracy.

Smartphone User: (perplexed)

Note: I, myself, don't know a lot about smartphone GPS. Could be I'm mistaken about a lot of it, too.