AWACS vs JSTARS

[Charles Talleyrand]

Most radar command and control (AWACS) planes have the radar mounted
high above the fuselage and mounted horizontally. This means that the
radar cannot see below the plane since the radar is pointed the wrong
direction and there are both wings and fuselage between radar and the
ground.

The new JSTARS plane has radar antennas mounted on the lower fuselage
and angled downwards. This means that it does not have all around
coverage (nothing pointed front or rear) and even sideways has angle
limitations, since it's hard for the radar to see through the wings
and engines.

But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).

The obvious answer is to have an AWACS style radar mounting and then
for ground surveillance the plane stands off a considerable distance,
so that the radar is looking past the wings/fuselage, and not through
them. However looking at such an angle causes buildings and hills to
cast longer radar shadows than looking at a more vertical angle.

In practice, what is done to solve this? And in theory how might one
overcome these difficulties?

-Charles Talleyrand

[Typhoon502]

Post by Charles Talleyrand
Most radar command and control (AWACS) planes have the radar mounted
high above the fuselage and mounted horizontally. This means that the
radar cannot see below the plane since the radar is pointed the wrong
direction and there are both wings and fuselage between radar and the
ground.
The new JSTARS plane has radar antennas mounted on the lower fuselage
and angled downwards. This means that it does not have all around
coverage (nothing pointed front or rear) and even sideways has angle
limitations, since it's hard for the radar to see through the wings
and engines.

Luckily, the planes are designed for two completely different
missions. AWACS covers airborne traffic, JSTARS covers surface
traffic. Both aircraft are specifically configured for their missions.

[Typhoon502]

Post by Charles Talleyrand
But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).
The obvious answer is to have an AWACS style radar mounting and then
for ground surveillance the plane stands off a considerable distance,
so that the radar is looking past the wings/fuselage, and not through
them. However looking at such an angle causes buildings and hills to
cast longer radar shadows than looking at a more vertical angle.
In practice, what is done to solve this? And in theory how might one
overcome these difficulties?

I posted too soon. :-/ At any rate, I'm not sure you really want to
try to stuff both missions into one airframe, unless it's the size of
a 777 and can handle the hardware, power, cooling, and manning
requirements that you'd need to really, properly push enough wattage
through the sky.

[Pat Flannery]

Post by Typhoon502
I posted too soon. :-/ At any rate, I'm not sure you really want to
try to stuff both missions into one airframe, unless it's the size of
a 777 and can handle the hardware, power, cooling, and manning
requirements that you'd need to really, properly push enough wattage
through the sky.

Doing things like that in a stealthy manner was the concept behind Tacit
Blue: http://ftp.fas.org/irp/mystery/tacitblu.htm
As far as manning requirements, the plane could carry just a pilot; all
data from the radar could be up-linked to a satellited and from there to
a command center, where everything could be viewed, and from where the
radar on the aircraft could be commanded from. In fact, this mission
could be done by a large UAV instead of a manned aircraft.
That would lighten it up enough to give it greater mission duration or
higher altitude capabilities.
It certainly wouldn't be cheap though.

Pat

[Charles Talleyrand]

Post by Typhoon502

Post by Charles Talleyrand
But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).
The obvious answer is to have an AWACS style radar mounting and then
for ground surveillance the plane stands off a considerable distance,
so that the radar is looking past the wings/fuselage, and not through
them. However looking at such an angle causes buildings and hills to
cast longer radar shadows than looking at a more vertical angle.
In practice, what is done to solve this? And in theory how might one
overcome these difficulties?

I posted too soon. :-/ At any rate, I'm not sure you really want to
try to stuff both missions into one airframe, unless it's the size of
a 777 and can handle the hardware, power, cooling, and manning
requirements that you'd need to really, properly push enough wattage
through the sky.

I do not think that such a plane could do both missions at the same
time. However a military might want to have the flexibility to do
either mission as needed.

Consider Australia and Turkey. Both are buying AWACS style planes,
but probably wish they could have a more flexible plane. What could
be done to produce such a plane?

[d***@hotmail.com]

Post by Charles Talleyrand

Post by Typhoon502

Post by Charles Talleyrand
But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).
The obvious answer is to have an AWACS style radar mounting and then
for ground surveillance the plane stands off a considerable distance,
so that the radar is looking past the wings/fuselage, and not through
them. However looking at such an angle causes buildings and hills to
cast longer radar shadows than looking at a more vertical angle.
In practice, what is done to solve this? And in theory how might one
overcome these difficulties?

I posted too soon. :-/ At any rate, I'm not sure you really want to
try to stuff both missions into one airframe, unless it's the size of
a 777 and can handle the hardware, power, cooling, and manning
requirements that you'd need to really, properly push enough wattage
through the sky.

I do not think that such a plane could do both missions at the same
time. However a military might want to have the flexibility to do
either mission as needed.
Consider Australia and Turkey. Both are buying AWACS style planes,
but probably wish they could have a more flexible plane. What could
be done to produce such a plane?

The E-10 program is trying to do both in one airframe, but last time I
heard,
that program was in serious budget trouble. See:

http://en.wikipedia.org/wiki/E-10_MC2A

and

http://integrator.hanscom.af.mil/2005/July/07072005/07072005-14.htm

[Charles Talleyrand]

Post by d***@hotmail.com

Post by Charles Talleyrand

Post by Typhoon502

Post by Charles Talleyrand
But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).
The obvious answer is to have an AWACS style radar mounting and then
for ground surveillance the plane stands off a considerable distance,
so that the radar is looking past the wings/fuselage, and not through
them. However looking at such an angle causes buildings and hills to
cast longer radar shadows than looking at a more vertical angle.
In practice, what is done to solve this? And in theory how might one
overcome these difficulties?

I posted too soon. :-/ At any rate, I'm not sure you really want to
try to stuff both missions into one airframe, unless it's the size of
a 777 and can handle the hardware, power, cooling, and manning
requirements that you'd need to really, properly push enough wattage
through the sky.

I do not think that such a plane could do both missions at the same
time. However a military might want to have the flexibility to do
either mission as needed.
Consider Australia and Turkey. Both are buying AWACS style planes,
but probably wish they could have a more flexible plane. What could
be done to produce such a plane?

The E-10 program is trying to do both in one airframe, but last time I
heard,
that program was in serious budget trouble.

I guess they had developmental problems. Quoting wikipedia "In August
2003 Air International reported that the goal of integrating air- and
ground-search radars on a single airframe has been abandoned.
Electronic interference between the AESA and ground-surveillance
radars as well as the power requirements for both systems is cited as
the reason. Instead the USAF will operate two separate E-10 fleets".

This makes it sound as if Boeing was trying to run to separate radars
at the same time, one for ground and one for air-air, and that neither
radar was good enough at the job of the other.

Is there something about an air-search radar that makes it work less
well for ground search, and visa-versa?

I also read that the IAI EL/M-2075 Phalcon is the best airborne
surveillance radar in the world. Who knew? :-)

[150flivver]

Post by Charles Talleyrand
Is there something about an air-search radar that makes it work less
well for ground search, and visa-versa?

Physics.

[Charles Talleyrand]

Post by 150flivver

Post by Charles Talleyrand
Is there something about an air-search radar that makes it work less
well for ground search, and visa-versa?

Physics.

Wow. What a great reply. I probably don't need any more of your help
in the future; I think I've had enough.

[Harry Andreas]

Post by Charles Talleyrand

Post by 150flivver

Post by Charles Talleyrand
Is there something about an air-search radar that makes it work less
well for ground search, and visa-versa?

Physics.

Wow. What a great reply. I probably don't need any more of your help
in the future; I think I've had enough.

OK, here's a better answer:

Introduction to Airborne Radar, 2nd Ed, Stimson, Scitech Publishing, 1998

for Air to air read chapters 7 thru 21 then 25 thru 29
for Air to ground read chapters 22 thru 24 then 30 thru 33

BTW this is one of the standard textbooks of the industry and
is used world-wide.

[Tankfixer]

Post by Charles Talleyrand

Post by Typhoon502

Post by Charles Talleyrand
But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).
The obvious answer is to have an AWACS style radar mounting and then
for ground surveillance the plane stands off a considerable distance,
so that the radar is looking past the wings/fuselage, and not through
them. However looking at such an angle causes buildings and hills to
cast longer radar shadows than looking at a more vertical angle.
In practice, what is done to solve this? And in theory how might one
overcome these difficulties?

I posted too soon. :-/ At any rate, I'm not sure you really want to
try to stuff both missions into one airframe, unless it's the size of
a 777 and can handle the hardware, power, cooling, and manning
requirements that you'd need to really, properly push enough wattage
through the sky.

I do not think that such a plane could do both missions at the same
time. However a military might want to have the flexibility to do
either mission as needed.

IIRC the E-2C has a good bit of surface search capabilities.
But not near the multiple targets in ground clutter that J-STARS can
handle

Post by Charles Talleyrand
Consider Australia and Turkey. Both are buying AWACS style planes,
but probably wish they could have a more flexible plane. What could
be done to produce such a plane?

[d***@hotmail.com]

[SNIP]

Post by Tankfixer
IIRC the E-2C has a good bit of surface search capabilities.
But not near the multiple targets in ground clutter that J-STARS can
handle

[SNIP]

The USN also has a new JSTARS-esque radar mounted on some
of its P-3's. See:

http://aviationweek.typepad.com/ares/2007/05/notquitesecret_.html

[Tankfixer]

Post by d***@hotmail.com
[SNIP]

Post by Tankfixer
IIRC the E-2C has a good bit of surface search capabilities.
But not near the multiple targets in ground clutter that J-STARS can
handle

[SNIP]
The USN also has a new JSTARS-esque radar mounted on some
http://aviationweek.typepad.com/ares/2007/05/notquitesecret_.html

Some P-3, not sure it they were this version, have been used over
Central Africa for surveillance missions.


--
Usenetsaurus n. an early pedantic internet mammal, who survived on a
diet of static text and
cascading "threads."

[KP]

Post by Charles Talleyrand
But one might reasonably want a radar plane useful for both ground
surveillance and air control, especially for a smaller nation that
cannot afford too many aircraft (i.e. anyone except the U.S.).

One might want a platform that can do both as well as perform the actual
intercept/strike, walk the dog, change the baby, and do your math homework
but that's asking a bit much of a single platform.

Besides the two different missions the two systems are designed to perform
there are also size, space, and employment limitations.

How large an aircraft would it take to lift both radar systems along with
the comm gear and personnel to use it all?

How much would such an aircraft cost to buy, maintain, and operate?

How many "smaller nations" really have the other assets necessary to employ,
protect, and effectively utilize the information provided by this combined
AWACS/JSTARS?

Aircraft droning around in the sky with big radars aren't really any good
for anything in and of themselves.

[Vee-One]

"Charles Talleyrand" <***@gmail.com> wrote in message news:***@u30g2000hsc.googlegroups.com...

<SNIP>

Very good answers by all ('cept one). Having worked MX on BOTH, I can give
you the wrench-turner's view, as I worked on the radar systems of both.

Vee-One

[Charles Talleyrand]

Post by Vee-One
<SNIP>
Very good answers by all ('cept one). Having worked MX on BOTH, I can give
you the wrench-turner's view, as I worked on the radar systems of both.
Vee-One

Well, please do. I'm interested.

[Vee-One]

Post by Charles Talleyrand

Post by Vee-One
<SNIP>
Very good answers by all ('cept one). Having worked MX on BOTH, I can give
you the wrench-turner's view, as I worked on the radar systems of both.
Vee-One

Well, please do. I'm interested.

Well, the biggest pain we associated with JSTARS wa the fact they were built
on refurbished airframes. Used 707, striped and rebuilt. AWACS were built
as new airframes, bu are now 25-30 years old. Each has it's own "problem"
areas. JSTARS tended to be engines and fuel cells (when I worked them 4
years ago). AWACS it was always the radar systems, although that vastly
improved folowing RSIP.

The idea of having one airplane to do it all is an exciting thought, as it
would have involved a new airframe (767?, the Japanese use that for their
AWACS), but the reality is that it would be WAY to expensive for the AF, and
they were already talking about having 2 different airplanes which defeated
the purpose IMHO.

But to me, in the end a job's a job, and it really didn't matter which
airplane I worked. Each has an equally important mission to do and I was
proud to be a part of it.

Vee-One