Bob Noel wrote:

(Ron Lee) wrote:

True Steven but they do own WAAS (a GPS augmentation system) which
they seem to make essential to many programs such as ADS-B Out.

huh? What is the relationship/interaction between WAAS and ADS-B?

Bob Noel

Look at the ADS-B Out NPRM, page 56956, third column (right side of
page) for these points which IMO seems that the FAA conveniently
specify ADS-B Out performance requirements that can only be met using
GPS augmented with WAAS.

"This proposal specifies performance standards for aircraft avionics
equipment for operation to enable ADS B Out. These performance
standards would accommodate and facilitate the use of new technology.
Presently, GPS augmented by the Wide Area Augmentation System (WAAS)
is the only navigation position service that provides the level of
accuracy and integrity (NIC, NACp, and NACv) to enable ADS-B Out to be
used for NAS based surveillance operations with sufficient
availability."

Plus near the bottom of that column:

"In order to meet the proposed performance requirements using the
GPS/WAAS system, aircraft would be required to have equipment
installed onboard the aircraft that meets one of the following: (1)
TSO C145b, Airborne Navigation Sensors using the GPS augmented by
WAAS; or (2) TSO-C146b Stand-Alone Airborne Navigation Equipment using
the GPS augmented by WAAS."

Ron Lee