WAAS?

[nubb1337]

What is WAAS?

[+Suburban Hillbillies]

In a nutshell...

 

It's a set of ground stations ( not satellites ) that send signals to the GPS to provide "corrections" to the data it receives. I understand this is useful in urban areas with large buildings that may block some of the orbiting satellites.

 

Not exactly sure what WAAS stands for though...

[me_chris]

Wide Area Augmentation System - makes your GPS more accurate by correcting some of the error inherent in satellite communications...

 

Check out the Wikipedia article here: WAAS

[+Suburban Hillbillies]

WAAS = Wide Area Augmentation System

 

Just googled it to see. Lots of cool info out there.

[+StarBrand]

It is a ground based system to correct (at least somewhat) for atmospheric errors in transmission timing. Over simplified, a series of ground stations at well surveyed points calculate the needed corrections and trasmit those to a central system that calculates a mathamatical model of the atmosphere over a region and then uses specially designated sats to transmit that correction info back to users.

[+The Leprechauns]

I read many posts saying how people logged a lot more smilies using WAAS.

 

I always thought it meant "Wisconsin Auxiliary Activity Smilies."

 

I guess you learn something every day.

[+team lagonda]

never use it..dont think it would be much good unless the hider used it ..its realy hit and miss getting those satelites round here....in fact my instruction book says if your not going to use it to disable it and your gps will be more accurate....wait a minute,,what waas that question again....last i did use waas i got lost and didnt know where i waas....but on the other hand that waas a long time ago..as to the op,s title of the thread what is waas..waas is on second ,what is on first..it would be a interesting survey how many people use waas....

Edited December 27, 2007 by team lagonda

[MikeB3542]

It seems that the satellites that use this technology never are high enough to be received regularly, at least in my neck of the woods. It seems to use up alkaline batteries VERY efficiently

[+fairyhoney]

Sounds interesting but I've never heard of it nor have used it before

[+Dryphter]

WAAS UP?

[+trainlove]

In a nutshell...

 

It's a set of ground stations ( not satellites ) that send signals to the GPS to provide "corrections" to the data it receives. I understand this is useful in urban areas with large buildings that may block some of the orbiting satellites.

 

Not exactly sure what WAAS stands for though...

 

Sure it's ground stations. But those ground stations are only used to calculate the ionospheric distortions inherent in the c-band GPS signals. The actual signals you get on your GPSr come from WAAS "satellites". Those satellites are geostationary, actually are transmitters leased on TV and other existing satellites.

 

While the GPS satellites are half way up to geostationary. They actually reach the same spot twice a day, but the second time the earth has turned half way around. I.E. PRN17 might be in Hercules right now at 9pm, which is not visible to us this time of year at this time of day, then 12 hours later at 9am it will be in Hercules again which is up but it's daytime for us astronomers but for us GPS users that does not matter. There is actually about a 4 minute shortage in the orbit so it keeps time with the stars, not the sun. I.E. I will always be in Hercules at both 9PM and 9AM.

 

Well a better example might be, satellites 28, 8 27 & 11 al converge right now about 9am, but 6 months from now at 9am they will still converge but be exactly on the opposite side of the earth, but at 9pm you will see them up and converging. If you could see right through them you would see the same particular spot in dep space.

 

Edited to add:

P.S. My backup GPS a Garmin GPS48 does not hae WAAS capability and it still serves me right when my normal unit is down for one reason or another.

Edited December 27, 2007 by trainlove

[+egami]

never use it..dont think it would be much good unless the hider used it ..its realy hit and miss getting those satelites round here....in fact my instruction book says if your not going to use it to disable it and your gps will be more accurate....wait a minute,,what waas that question again....last i did use waas i got lost and didnt know where i waas....but on the other hand that waas a long time ago..as to the op,s title of the thread what is waas..waas is on second ,what is on first..it would be a interesting survey how many people use waas....

 

It would be interesting to survey how many use WAAS.

[zulutime]

 

Sure it's ground stations. But those ground stations are only used to calculate the ionospheric distortions inherent in the c-band GPS signals.

 

Astounding!

[+Glenn]

To understand why WAAS works and what it can do for you you first have to understand basically how your GPS works. Your GPS receives almanac data. Simplistically, this almanac data tells your GPS where each satellite is located above the earth. Also each satellite transmits a time code. Because we know how fast radio waves travel your GPS can determine how far you are from each satellite.

 

Unfortunately our atmosphere can't be relied upon to be, simplistically speaking, the same thickness everywhere at the same time. This means that signals passing through thicker parts take longer than normal to get to your GPS. Your GPS has no way of knowing if you have moved further from a particular satellite or if the atmosphere is slowing down that particular signal. So your GPS takes this information and gives you a best guess on your actual position. It also calculates an error distance or radius. Some GPSes call this EPE (Estimated Positional Error).

 

Finally we get to WAAS. Atmospheric conditions are one of the, if not THE, major cause of position errors. That is why WAAS was invented. WAAS earth stations monitor the signals from GPS satellites from a fixed location on earth. Since these earth stations don't move around they know exactly how long it should take each signal to get to them at their specific location. When they notice any difference they send this information to your GPS. Your GPS then makes corrections in its position calculations. This almost completely eliminates any error in position and makes your GPS much more accurate.

[+larry739]

I can tell you for a fact that in my opinion (did you notice that/) WAAS has made my GPS more accurate except on one persons caches who shall remain nameless, because I do not want to hurt his feelings any more than I already have.

[boogie bear]

I believe WAAS was developed by the FFA so aircraft can zero in on airports more accurately...

[+Rattlebars]

You may find this acronym site useful. I have used it hundreds of times.

 

This link takes you to WAAS.

 

This link takes you to the main input page BLANK.

 

RATTLEBARS