FAA "Centers" have primary radar?

On Aug 6, 1:56 am, wrote

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/mo...sb.tc.faa.gov/

Secondary radar is the term for any transponder mode radar--A, C or S.

On Aug 5, 4:43 pm, "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.

--
Danny Deger

NASA offered me $15,000 to take down my web site. Take a look and see why.www.dannydeger.net

FAA Centers do have the capability to paint primary targets. The
quality of radar coverage for primary targets is somewhat spotty. A
primary may or may not be painted depending on a lot of different
circumstances. Weather affects this capability too. Since we do have
primary capability, it can paint flocks of birds, weather, non-
transponder equipped planes, etc. We have recently gotten an upgrade
to our scopes that allows better weather depiction. Previously weather
depiction was very inaccurate. Our radar antennas turn at a speed
twice that or normal weather radar so our depiction used to be very
poor. I am an air traffic controller - 27+ years.

"BT" wrote in message
...
what was the altitude.. where you below the "radar horizon" for the range
from the antenna?
Was the "target aircraft" in a "blind radar area for the altitude" based
on a close in obstruction such as earth or building?

Good question, but wouldn't the things you talk about affect the secondary
radar as well.

They were out over the Atlantic Ocean in a miltary Warning Area under the
control of Washington Center. After the acident, we were all briefed if we
lost our transponder Washington Center could not paint us. Apparently this
is not true for Centers in general. Maybe it had to do with Washington
Center's radar coverage out over the Atlantic.

You can read the details in my free book you can get at my web site
www.dannydeger.net. Look on page 31. I have lots of other good flying
stories in the book you might enjoy.

Danny Deger

B

"Danny Deger" wrote in message
...
"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.

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 at
www.dannydeger.net

Danny Deger

On Aug 6, 1:56 am, wrote:


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/mo...sb.tc.faa.gov/



Secondary "radar" is any type of system where the target is an active
particpant in the radio direction and ranging system. In the US civil
airways system this can be mode a/c/s and it is all the same (more or
less) technical description...

aka the main Secondary system sends out an interrogation pulse on one
frequency and the target replies on another. The times are measured
(ie time main pulse went out and secondary pulse recieved) and hence
range is achieved. Direction is based on the pointing of the primary
interrogator.

"Beacon" Antennas are commonly (but not always) co located with main
primary radar...they will generally be the "flat" rectangle on top of
the main (larger) antenna. They can stand alone...and that is common
in places like Canada and Austrailia...they require far less power
then primary or skin paint radars.

Beacon (ie secondary radar) was a US invention in WWII...It was called
"IFF" identification friend or foe".

What seperates a primary radar for ATC and one for WX are the
characteristics of the radar. Frequency is important but more so are
pulse repetition rate (PRR), polarization, and antenna rotation rate.
Most people think that there is one "echo returned" from a
target...this is not correct.

The PRR and antenna rotation rate are designed to maximise the number
of "Paints" of a target on a particular sweep.

Robert

On Aug 6, 8:30 am, ATControlr wrote:
On Aug 5, 4:43 pm, "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.

--
Danny Deger

NASA offered me $15,000 to take down my web site. Take a look and see why.www.dannydeger.net

FAA Centers do have the capability to paint primary targets. The
quality of radar coverage for primary targets is somewhat spotty. A
primary may or may not be painted depending on a lot of different
circumstances. Weather affects this capability too. Since we do have
primary capability, it can paint flocks of birds, weather, non-
transponder equipped planes, etc. We have recently gotten an upgrade
to our scopes that allows better weather depiction. Previously weather
depiction was very inaccurate. Our radar antennas turn at a speed
twice that or normal weather radar so our depiction used to be very
poor. I am an air traffic controller - 27+ years.

You seem amazingly lucid for having been a controller for almost 30
years. Congratulations. I would have blown a fuse in about 2 days!

Robert

I would like thank everybody for all of the information. I have made
changes to my book to reflect Centers in general have skin paint capability.
There must be something unique about Washington Center's radar out over the
Atlantic Ocean Warning Areas that prevented them from getting a skin paint
on my friend's F-4.

The short summary of my friend's fatal flight is: he lost all electrical
power and decided to rejoin on another F-4 in the warning area. The lights
he picked out were not an F-4, but an airliner out over the ocean headed to
Miami (we were off the coast of North Carolina). By the time they realized
their mistake, they didn't have enough fuel to get back to land and ended up
bailing out in the ocean. 6 days later a fishing trawler picked up the back
seater and the front seater was never found. Without a skin paint, the
search and rescue forces looked in the wrong place.

More details in my book you can get for free from my web site. Feel free to
download and email to your friends.

--
Danny Deger

NASA offered me $15,000 to take down my web site. Take a look and see why.
www.dannydeger.net

On Aug 6, 11:34 am, "Danny Deger" wrote:
I would like thank everybody for all of the information. I have made
changes to my book to reflect Centers in general have skin paint capability.
There must be something unique about Washington Center's radar out over the
Atlantic Ocean Warning Areas that prevented them from getting a skin paint
on my friend's F-4.

The short summary of my friend's fatal flight is: he lost all electrical
power and decided to rejoin on another F-4 in the warning area. The lights
he picked out were not an F-4, but an airliner out over the ocean headed to
Miami (we were off the coast of North Carolina). By the time they realized
their mistake, they didn't have enough fuel to get back to land and ended up
bailing out in the ocean. 6 days later a fishing trawler picked up the back
seater and the front seater was never found. Without a skin paint, the
search and rescue forces looked in the wrong place.

More details in my book you can get for free from my web site. Feel free to
download and email to your friends.

--
Danny Deger

NASA offered me $15,000 to take down my web site. Take a look and see why.www.dannydeger.net

Danny

I would add this "thing" ...it might not be all that unique. it just
might be "how it is"...for all centers.

The SSR range for a "radar" is (because of the active particpant) must
longer then skin paint. I dont know what year it was, but the
"computer" system probably rejected the target in part because of some
"angle" issues (ie two systems were painting it and it fell out of a
"cell" ie both radars present information to the computer and the
computer gets confused because it cannot corelate teh target(s) and
just drops the target).

On 9/11 when the airlines went "primary" it was only some really
quick thinking by the folks at NY center that held them as targets.

The sad thing (different topic) is that more or less the FAA worked
"as advertised" on 9/11. They were about the only one.

Robert

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.

There is no connection whatever between 'primary radar' and 'weather radar'.

The ability to detect storm clouds is related purely to the wavelength of the
radar transmission. A radar that was swamped by cloud returns would be utterly
useless as a primary radar !

Graham

In rec.aviation.piloting Danny Deger wrote:
I would like thank everybody for all of the information. I have made
changes to my book to reflect Centers in general have skin paint capability.
There must be something unique about Washington Center's radar out over the
Atlantic Ocean Warning Areas that prevented them from getting a skin paint
on my friend's F-4.

Or the F-4 was too small to paint, or the radar was broken that day, or
lots of other things could have been in play.

Having spent more hours than I care to remember behind military air
defense radar systems, I can say with some authority that a single
fighter is tough for any radar to see at long ranges.

--
Jim Pennino

Remove .spam.sux to reply.

In rec.aviation.piloting Eeyore wrote:


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.

There is no connection whatever between 'primary radar' and 'weather radar'.

The ability to detect storm clouds is related purely to the wavelength of the
radar transmission. A radar that was swamped by cloud returns would be utterly
useless as a primary radar !

Bzzzt, wrong answer.

The ablility of radar to detect weather is related to frequency, antenna
polarization, antenna sweep rate, type (as in pure pulse versus doppler)
and signal processing (if any).

Most search radar used for finding airplanes won't see ordinary clouds
at all and are generally marginal for seeing precipitation unless you've
put something in the design to do both.



--
Jim Pennino

Remove .spam.sux to reply.