Ed S wrote:
I searched around a bit and couldn't seem to find any talk about an
opensource implementation of ADS-B (and maybe some open hardware). Has
anyone heard of such a project?

It sounds like a worthy project to keep the prices from Garmin and the
like in check so a opensource applications can be written to use
utilize the underlying ADS-B implementation.

Well I'm not surprised - the comment period for the NPRM just closed. In
fact some of the comments from the Aircraft Electronics Association[1]
seem to indicate not much exists (for light aircraft anyway):

"Because the FAA has established this revolutionary change in basic
ADS-B performance requirements, there isn't any equipment that currently
meets the Minimum Performance Standard for light general aviation
aircraft."

And they point out that the proposal doesn't make clear whether the
equipment must be FAA approved, as noted in this quote:

"The FAA once again publishes the performance requirements of equipment,
but does not require that the equipment be FAA-approved. This
continually causes confusion within the industry.

In the proposed 91.225, the FAA should clarify when the ADS-B equipment
must be "FAA approved" and when the manufacturer simply needs to show
that the ADS-B meets the performance requirements of the respective
TSO."

A "worthy" project? Hmmm. Any requirment that a citizen who has done
nothing wrong must be denied access to a public commons as vast as the
national airspace (which is a right by the way, not a privilege[2])
unless that person broadcasts an ID that uniquely identifies that person
would seem to be grounds for a lawsuit if that requirement appears in
the final rules. Whether it can prevail in the face of ever greater
assumption of state patronization of its citizens seem, alas,
problematic. :-(

[1]
http://www.regulations.gov/fdmspubli...ntentType=msw8

[2] "United State Code TITLE 49 - TRANSPORTATION

Sec. 40103. Sovereignty and use of airspace
....
(2) A citizen of the United States has a public right of transit through
the navigable airspace."