GPS accuracy - I see not much has changed

On Fri, 20 Nov 2009 22:18:25 -0800, "floyd rogers"
> wrote:

>"Matthew Russotto" > wrote
>> There has been one change since then which will allow more accuracy
>> and precision; wide area differential GPS. However, unless my
>> information is out of date, the satellites capable of that have little
>> coverage and most of it is on water. Many GPS units can use it if
>> available though.
>
>Not quite right. It's WAAS, Wide Area Augmentation System. This
>system uses around a dozen ground systems that cover N. America
>and send out corrections for atmospheric variations. It allows guaranteed
>30-meter (IIRC) accuracy.

Is that for Vertical or Horizontal accuracy??


This is used by airplanes equipped with GPS
>and flight-control software to accurately follow constrained landing paths.
>All of Alaska Airlines planes are equipped, and they use the RNAV
>capabilities to fly into valleys on pre-defined paths; and into Washington
>National because of it's security corridor.
>
>Many hand-held GPSs have WAAS capabilities, but it hardly matters.
>
>FloydR
>

"Ashton Crusher" > wrote
> On Fri, 20 Nov 2009 22:18:25 -0800, "floyd rogers"wrote:
>
>>"Matthew Russotto" > wrote
>>Not quite right. It's WAAS, Wide Area Augmentation System. This
>>system uses around a dozen ground systems that cover N. America
>>and send out corrections for atmospheric variations. It allows guaranteed
>>30-meter (IIRC) accuracy.
>
> Is that for Vertical or Horizontal accuracy??

Both: http://www.aviationbanter.com/showthread.php?t=15401

FloydR