On Aug 5, 3:58 pm, "Danny Deger" wrote:
"Bob" wrote in message

...

On Sun, 5 Aug 2007 15:43:29 -0500, "Danny Deger"
wrote:

In another thread I am in a discussion on radar capability for FAA
"Centers". My recollection is that they typically have no primary radar,
thus no capability to paint weather. Someone is telling me they do.
Anybody out there have the answer. Maybe some do and some don't, and the
ones I used in the past don't.

"FAA Primary En Route Long Range Radar Restructuring Program
The FAA currently uses and supports 126 primary en route radar
facilities. The FAA is chartered to provide Primary radar services to
all federal agencies requiring this data to meet their operational
missions."
http://www.faa.gov/asd/ia-or/longrangeradar.htm

Thanks for the link. I found it very useful. I think my confusion comes
from an accident where a friend of mine died because Washington Center lost
radar contact when he lost his transponder. He was out over the ocean in a
warning area. We were briefed Washington Center had no ability to skin
paint. I am starting to realize this probably had to do only with this
situation of being over the ocean in a warning area and Centers in general
have skin paint capable radars.

My understanding of FAA radar is the transponder is just used to ID
the aircraft and provide altitude information. A plane with a
defective transponder can be seen on radar, but no ID or altitude.
The transponder is pinged at 1030MHz, and responds on 1090MHz. I
believe the actually locating radar is in a different band. Note the
911 hijackers turned off the transponders, but the planes were still
tracked.

Someone mentioned secondary surveillance. This is mode-s. It is also
on 1030/1090Mhz. However, the reply from the transponder is more
detailed. It contains a unique code for each aircraft. The older
transponders simply return the squawk code that was assigned by ATC
and entered by the pilot. Some mode-s can return airspace and
location.

http://mit.edu/6.933/www/Fall2000/mode-s/
http://adsb.tc.faa.gov/





If anyone is interested in the details of this fatal flight, I put them in
my book, "Houston, You Have a Problem" and you can get it for free atwww.dannydeger.net

Danny Deger