Build your own PowerFLARM!

On Aug 16, 9:37 pm, Mike Schumann
wrote:
On 8/16/2010 10:50 PM, kirk.stant wrote:
[snip]
A. "Right Now Benefits of PowerFlarm" - This product does not currently
exist. Has it been submitted to the FCC for approval yet? What is the
expect ship date?

Late 2010/December according to their USA dealers.

[snip]

C. PCAS - How does PCAS tell you anything about what kind of target is
aiming for you? In fact, it doesn't give you any information on where
the target is, whether it's getting closer or moving away. All you know
is altitude and range (NO bearing). It's not going to tell you if it's
a jet, another glider, or your tow plane. And you are only going to get
that much info if the transponder equipped plane is being interrogated.
That's not a given if you are flying low in remote areas without radar
coverage.

What is your point? If the PCAS in PowerFLARM works anwhere nears as
well as PCAS units like the Zaon MRX then it is a very useful tool
today especially against GA threats. Yes there are restrictions on
this, and they've been discussed to death already.

Including PCAS capabilities in a 1090ES receiver is easy since all the
hardware you need is already there for free. It is just plain and
simple a really great idea to add that feature in this product. I
expect other 1090ES receiver manufacturers in the portable/low-end
market to do exactly the same. Of course without additional 1090MHz
receiver hardware a UAT receiver cannot do this.

But to caution other folks here, PCAS relies on the inverse square of
distance fall of in RF power and assumptions about transponder power
output to guesstimate distance, while it works OK it has limits. It is
part of the reason why PCAS systems have a relatively short warning
range for threats. With fast closure rates like with airliners and
jets (esp. at altitude/outside airspace speed restrictions) PCAS
systems are quite likely to give unusably short warning times. I see
PCAS as making more sense with GA threats and when flying with a
reasonably small number of gliders -- what many of us have done with
it given the lack of Flarm availability in the USA.

What's my agenda? Making sure that people know what they are buying and
the limitations thereof.

--
Mike Schumann


Darryl