On Jun 29, 12:17*am, ursus wrote:
On Jun 22, 6:42*am, Mike Schumann
wrote:

There is no inherent reason that ADS-B UAT transceivers using consumer
grade GPS and RF components can't be built for the same general price
point as FLARM units. *The only difference in the hardware is frequency
and transmit power.

The FLARM RF transceiver costs about $5 in parts. The ADS-B UAT
transceiver is how much ???
Most glider pilots are in complete denial about the commercial
realities of the gliding business:
Selling and supporting an *empty* box, with no production costs, to
glider pilots could not be done below USD 600 per unit.
It is not pretty, but that's the reality if your business intends to
still be around in a few years, while supporting and innovating for
the customers...

The MITRE unit
transmits "unknown" for integrity, as that information is not available
from a consumer grade GPS chipset.

The 'consumer grade' GPS chipset in FLARM provides all the information
you ever need:
DOP, accuracy estimates, pseudorange errors, satellite health and
whatever comes in through WAAS / EGNOS...
Some of that information is also transmitted in the FLARM signal and
used for alarm evaluation.
Just because a device is FAA certified does not mean it is better, it
just means it is outdated ;-)

Another note: *FLARM and ADS-B units are not a cure alls for collision
avoidance in competition flying. *The accuracy of the GPS fixes and the
update rates (even for units meeting the FAA's latest approved specs)
are not high enough to provide collision warnings for gliders that are
sharing a thermal in a gagle. *

The update rate and relative (!) precision of the GPS used in FLARM is
by far sufficient to do collision avoidance in glider competitions.
Other factors are more limiting.
However, if you stick various FAA approved GPS's into gliders your
relative position and velocity information will not be nearly as
good...

My dear US friends; we do agree that 'classic' FLARM is not the best
solution for the US. This is why we never launched it there.
Stay tuned for PowerFLARM; it will deliver all you need, soon.www.powerflarm.com

Urs - FLARM

Urs,

QUESTION: Will PowerFLARM only be monitoring ADB-B data from 1090ES
equipped aircraft? That's my understanding after listening to Daryl
Ramm's reply. Will I be able to monitor the lat/lon and altitude of
transponder equipped aircraft from the ADB-B ground stations
rebroadcasting that information (ADS-R or ... Relay feature of the ADB-
B program). If the ADB-B ground stations relay data from both UAT
equipped aircraft and transponder aircraft, then... will I be able to
get collision advisories from the same algorithm used with FLARM to
FLARM equipped gliders?

FYI... I have ordered one of the early delivery PowerFLARMs based on
the assumption that I can hear all the ADS-B and transponder equipped
aircraft.. either directly air-to-air with the 1090ES aircraft over
through the ADS-B ground stations. Is this a correct assumption? It's
really confusing ... all this ADS-B program stuff with dual
frequencies in the U.S.

Urs, my motivation for purchasing PowerFLARM was a near mid-air I had
at the Parowan 2010 Sports Nationals. If you go to the DAY6 IGC files
and look for these logs: 06LC4541.IGC (my log - Walter Rogers : WX a
Discus 2A) and 06LC4131.IGC (Richard Pfiffner: SD a Ventus) you will
see another near mid air coming out of the first turn. Our paths
intersected with about 15 feet vertical separation. Fortunately, I saw
the converging glider at the last moment and made a severe pitch down
to miss him. Richard never saw me... Ironically (or maybe... using
good sense) I decided to purchase my PowerFLARM from Richard.

Urs, we met briefly for dinner with Dave Nadler and Lee Kuhkle at the
SSA convention in Littlerock.

Looking forward to PowerFLARM and any future software upgrades that
will help with ADS-B...

Walt Rogers, WX