WAAS Channels?

[Barry S.]

I was looking the RNAV approach for Rwy 26 @ PHX and it lists a WAAS
Channel of 70321 W26A.

I am aware that WAAS provides addition precision to GPS signals, but
this is the first I've seen "WAAS Channels". I was under the
impression the GPS knew where it was and incorporated the proper
correction from WAAS.

What is a WAAS channel and what does the W26A correspond to?
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[Ron Rosenfeld]

Post by Barry S.
Channel of 70321 W26A.
I am aware that WAAS provides addition precision to GPS signals, but
this is the first I've seen "WAAS Channels". I was under the
impression the GPS knew where it was and incorporated the proper
correction from WAAS.
What is a WAAS channel and what does the W26A correspond to?
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Look in the AIM 5-4-5

The WAAS Channel Number allows the use of a specific 5 digit number to
select a specific final approach segment. The Approach ID (W26A) is an
airport unique 4-character combination for verifying the selection and
extraction of the correct final approach segment information from the
aircraft database.
--ron