Is there a place for Traditional CAS in the 21st century?

"Paul F Austin" wrote in message
.. .

"Thomas Schoene" wrote
Paul F Austin wrote:

When I first looked at F-35, it seemed a looong step backward in
terms of situational awareness, with virtually no rear-quadrant
visibility. DAS promises to fix that. If it works for F-35 then it
should work for UCAVs.

The bandwidth issue is still a real concern. That's a lot of data to
transmit via long-range RF signal, and there's already lots of
competition
for the spectrum. What's possible to do by wire or fiber inside the
aircraft may not be practical via radio to a remote operator.

TCDL provides 200Kbps downlink/10Mbps uplink service. That's adequate for
this kind of situatuational awareness. More downlink would allow more raw

For how many nodes/UCAVs at once?

data but in this case, the fusion of the six DAS thermal cameras occurs
on-board and only the FOV in the direction the user's HMS is pointed at
need
be downlinked. CDL provides uplink services at various rates from T1 up to
256Mbps but that's overkill. CDL also lacks the total system capacity that
would be required. Today. The USAF is busy expanding the satellite comm
network capacity in anticipation of increased traffic.

"John Keeney" wrote...

The bandwidth issue is still a real concern. That's a lot of data to
transmit via long-range RF signal, and there's already lots of competition
for the spectrum. What's possible to do by wire or fiber inside the
aircraft may not be practical via radio to a remote operator.

TCDL provides 200Kbps downlink/10Mbps uplink service. That's adequate for
this kind of situatuational awareness. More downlink would allow more raw

For how many nodes/UCAVs at once?

Another good point! What would the nominal/maximum number of simultaneous UCAV
missions be in a single theater? If there are ongoing UAV recce missions as
well, will there be enough infrastructure support for simultaneous control of
all the UAV/UCAVs?

Traditional CAS was seldom done with a single airplane. More often, flights of
2 airplanes would orbit an IP and alternate attacks under the control of a
single FAC. That provided a larger total ordnance loadout and reduced time
between individual attacks. It also provided backup in case one aircraft broke.

Similarly, CAS with UCAVs would likely require more than a single vehicle per
mission. With the proposed capability (DAS + TCDL, etc), the infrastructure for
UAV operator stations would be expensive as well as space-consuming. That type
of infrastructure would not likely accompany front-line units, but would be held
by separate, dedicated units.

Finally, while semi-autonomous recce UAVs could be controlled via satellite
links, time delays in control links would likely make high-altitude satellites
and/or multiple relays unsuitable for real-time control such as that needed in
CAS. One article I read on TCDL mentioned line-of-sight ranges of 100-160 KM,
which were very dependent on UAV altitude. Some CAS and target ID is very
difficult with high-altitude run-ins...

"John Keeney" wrote

"Paul F Austin" wrote ...

"Thomas Schoene" wrote
Paul F Austin wrote:

When I first looked at F-35, it seemed a looong step backward in
terms of situational awareness, with virtually no rear-quadrant
visibility. DAS promises to fix that. If it works for F-35 then it
should work for UCAVs.

The bandwidth issue is still a real concern. That's a lot of data to
transmit via long-range RF signal, and there's already lots of
competition
for the spectrum. What's possible to do by wire or fiber inside the
aircraft may not be practical via radio to a remote operator.

TCDL provides 200Kbps downlink/10Mbps uplink service. That's adequate
for
this kind of situatuational awareness. More downlink would allow more
raw

For how many nodes/UCAVs at once?

One for each TCDL link. What's your point?


data but in this case, the fusion of the six DAS thermal cameras occurs
on-board and only the FOV in the direction the user's HMS is pointed at
need
be downlinked. CDL provides uplink services at various rates from T1 up
to
256Mbps but that's overkill. CDL also lacks the total system capacity
that
would be required. Today. The USAF is busy expanding the satellite comm
network capacity in anticipation of increased traffic.



One part of the USAF's data network roadmap is to place switching nodes in
many aircraft, including tankers and MC2A to provide both the aggregate BW
and number of available links. There're complementary programs to increase
COMSAT capacity by using -less than MILSTAR- robust satellites and
transponders.

The data network roadmap is progressing "under the RADAR" because it gets a
lot less publicity than to Things That Go Fast And Explode but is IMO more
important.

"John R Weiss" wrote in message
news2G6c.42116$SR1.48965@attbi_s04...
"John Keeney" wrote...

The bandwidth issue is still a real concern. That's a lot of data to
transmit via long-range RF signal, and there's already lots of
competition
for the spectrum. What's possible to do by wire or fiber inside the
aircraft may not be practical via radio to a remote operator.

TCDL provides 200Kbps downlink/10Mbps uplink service. That's adequate
for
this kind of situatuational awareness. More downlink would allow more
raw

For how many nodes/UCAVs at once?

Another good point! What would the nominal/maximum number of simultaneous
UCAV
missions be in a single theater? If there are ongoing UAV recce missions
as
well, will there be enough infrastructure support for simultaneous control
of
all the UAV/UCAVs?

You are on to why atonomuous vehicles are necessary, Weiss.

Traditional CAS was seldom done with a single airplane. More often,
flights of
2 airplanes would orbit an IP and alternate attacks under the control of a
single FAC. That provided a larger total ordnance loadout and reduced
time
between individual attacks. It also provided backup in case one aircraft
broke.

The idea today is to develop a robotic wingman, where the wingman becomes a
loiterer, after the lead feeds it the buddy pack.

Similarly, CAS with UCAVs would likely require more than a single vehicle
per
mission. With the proposed capability (DAS + TCDL, etc), the
infrastructure for
UAV operator stations would be expensive as well as space-consuming. That
type
of infrastructure would not likely accompany front-line units, but would
be held
by separate, dedicated units.

That does not seem to be the case.

Finally, while semi-autonomous recce UAVs could be controlled via
satellite
links, time delays in control links would likely make high-altitude
satellites
and/or multiple relays unsuitable for real-time control such as that
needed in
CAS. One article I read on TCDL mentioned line-of-sight ranges of 100-160
KM,
which were very dependent on UAV altitude. Some CAS and target ID is very
difficult with high-altitude run-ins...

Better to lose a robot taking a look than a pilot containing vehicle.

"John R Weiss" wrote in message
news2G6c.42116$SR1.48965@attbi_s04...
"John Keeney" wrote...

The bandwidth issue is still a real concern. That's a lot of data to
transmit via long-range RF signal, and there's already lots of
competition
for the spectrum. What's possible to do by wire or fiber inside the
aircraft may not be practical via radio to a remote operator.

TCDL provides 200Kbps downlink/10Mbps uplink service. That's adequate
for
this kind of situatuational awareness. More downlink would allow more
raw

For how many nodes/UCAVs at once?

Another good point! What would the nominal/maximum number of simultaneous
UCAV
missions be in a single theater? If there are ongoing UAV recce missions
as
well, will there be enough infrastructure support for simultaneous control
of
all the UAV/UCAVs?

Traditional CAS was seldom done with a single airplane. More often,
flights of
2 airplanes would orbit an IP and alternate attacks under the control of a
single FAC. That provided a larger total ordnance loadout and reduced
time
between individual attacks. It also provided backup in case one aircraft
broke.

Similarly, CAS with UCAVs would likely require more than a single vehicle
per
mission. With the proposed capability (DAS + TCDL, etc), the
infrastructure for
UAV operator stations would be expensive as well as space-consuming. That
type
of infrastructure would not likely accompany front-line units, but would
be held
by separate, dedicated units.

Finally, while semi-autonomous recce UAVs could be controlled via
satellite
links, time delays in control links would likely make high-altitude
satellites
and/or multiple relays unsuitable for real-time control such as that
needed in
CAS. One article I read on TCDL mentioned line-of-sight ranges of 100-160
KM,
which were very dependent on UAV altitude. Some CAS and target ID is very

difficult with high-altitude run-ins...

Actually not all that good a point!

As I said elsewhere, the USAF plans to proliferate switch and relay nodes in
support aircraft like tankers, MC2A and possibly retrofitted AWACS and
JSTARs. HALE UAVs are also being considered for relay platforms. The number
of links and aggregate bandwidth planned for the not too distant future is
much greater than is available today.

That kind of network makes the UAV operators REMFs for sure. There's no more
need for a TCDL terminal in every foxhole (or in every FAC) to control UAVs
than there is now to control manned aircraft. UAVs aren't now and will be
even less in the future directly driven by a ground controller-except when
the mission requires it-. Enroute control is done by autopilot. That's why I
said (several posts ago) that airspace deconfliction is a major obstacle to
using UCAVs in the numbers required to do CAS.

Regarding the cost and ubiquity of terminals, consider Hunter UAVs. Hunter's
current Ground Control Station (GCS) occupies the back of a HMMV while IAI
Malat is developing a Compact GCS significantly smaller for installation in
e.g. C-130s. The Remote Video Terminal to recieve payload data is much
smaller and is intended to be available at the TOC.

During an actual engagement, a single controller should be able to control a
small number of aircraft, taking direct control during target aquistition
and weapon delivery and letting the autopilots handle the "cab rank"
aircraft. This is obviously complex, depending on the details of UCAV
requirements and the doctrines that derive from it. As easily, because
nobody wants a warhead on a blue forehead, all UCAV missions in proximity
with own troops might be required to be under direct control of an operator
at all times.

There's an enthusiasm to hang ordnance on the current generation of UAVs
which is probably a mistake. UAVs are designed to carry sensor payloads and
neither their sensor suite nor the ordnance loads meet the requirements for
CAS/BAI. The services and the manufacturers run the risk of screwing up and
giving UAVs an bad name as ordnance delivery vehicles by not specifying and
building UCAVs with the right characteristics to meet the mission. The first
time some idiot launches a Hellfire from a Predator at a blue target, you'll
see what I mean.

Paul F Austin wrote:
"John Keeney" wrote

"Paul F Austin" wrote ...

TCDL provides 200Kbps downlink/10Mbps uplink service. That's
adequate for this kind of situatuational awareness. More downlink
would allow more raw

For how many nodes/UCAVs at once?

One for each TCDL link. What's your point?

How many TDCL links can you suport in a single geographic region? The wider
the pipes are, they fewer a given segment of spectrum can support. There
are clever ways to stretch bandwidth, but there is ultimately a finite
limit.

--
Tom Schoene Replace "invalid" with "net" to e-mail
"Our country, right or wrong. When right, to be kept right, when
wrong to be put right." - Senator Carl Schurz, 1872

"Thomas Schoene" wrote
Paul F Austin wrote:
"John Keeney" wrote

"Paul F Austin" wrote ...

TCDL provides 200Kbps downlink/10Mbps uplink service. That's
adequate for this kind of situatuational awareness. More downlink
would allow more raw

For how many nodes/UCAVs at once?

One for each TCDL link. What's your point?

How many TDCL links can you suport in a single geographic region? The
wider
the pipes are, they fewer a given segment of spectrum can support. There
are clever ways to stretch bandwidth, but there is ultimately a finite
limit.

That's true and it's a serious problem. First the obligatory disclaimer.
This is frankly outside my area, not being a RF comms guy, so if I step on
my crank, I'm sure someone will point it out.

Frequency diversity can carry you only so far. TCDL operates (on the return
link) over a 400MHz band with 5MHz channel spacing. I don't know if adjacent
channels can operate within LOS of each other but that's 80 channels at best
whose antennas can "see" each other. Directional links will carry you a ways
also since the operating band, Ku/K, is highly directional and the apertures
are small. TCDL is intended to work in other bands as well. Ka and Q bands
offers substantial available BW.

Certainly the problems of directional RF comms between maneuvering aircraft
are being solved as part of the IFDL development for F-22 and F-35. The F-22
IFDL antenna, providing hemispherical coverage and 78 switched beams weighs
5.4 pounds and occupies 250 cubic inches. This antenna
http://www.emsstg.com/defense/ant_data_link.asp operates in Q band
(30-50GHz) but gives you an idea of what's possible. An equivalent TCDL
aperture in Ku/K band would be larger because of the lower frequency.

Another answer may be LASER links, much work is going on in this area. When
I worked on a controller for LASER cross-links for (now defunct) Teledesic,
the spot size was about 6 inches in diameter into a receiver about 4X bigger
over GEO kinds of distances but that was for a non-maneuvering satellite
with known ephemeris. It did require a closed-loop tracker because even the
minimal vibrations in an orbiting spacecraft could cause the spot to walk
when working over those distances. The challenges of two maneuvering
aircraft communicating by LASER are substantial but given GPS and a stable
element at both ends, cooperative aiming should be possible.

All of these things are_possible_but they all cost money. If I start from
the position that UCAVs are candidates for future CAS/BAI missions, then the
projected UCAV is burdened with something like the ICNIA suite with things
like IFDL. A CAS UCAV won't be cheap. That's why I mentioned that some have
suggested a pilotless F-35 as a UCAV candidate. There will be_some_cost
advantages in such an aircraft but we're not talking about a $150K model
airplane with a pair of SDBs under the wings and a minigun slung under the
fuscelage.

This is the kind of thing that USENET lends itself least to since serious
trades require serious analysis. The information above came from 5 minutes
with Google and FAS's site. Handwavium is poor substitute for real
engineering. I apologize to John for getting a bit snippy in my answer to
him. I'm certainly not casting myself as an authority in these matters
who's_done_the trades touched on above.

"Paul F Austin" wrote in message
.. .

"John Keeney" wrote

"Paul F Austin" wrote ...

"Thomas Schoene" wrote
Paul F Austin wrote:

When I first looked at F-35, it seemed a looong step backward in
terms of situational awareness, with virtually no rear-quadrant
visibility. DAS promises to fix that. If it works for F-35 then it
should work for UCAVs.

The bandwidth issue is still a real concern. That's a lot of data
to
transmit via long-range RF signal, and there's already lots of
competition
for the spectrum. What's possible to do by wire or fiber inside the
aircraft may not be practical via radio to a remote operator.

TCDL provides 200Kbps downlink/10Mbps uplink service. That's adequate
for
this kind of situatuational awareness. More downlink would allow more
raw

For how many nodes/UCAVs at once?

One for each TCDL link. What's your point?

That if you have 100 UCAVs that need to be engaged that you need your
down & up links to be able to handle 100 UCAVs at once. Granted, most
planes currently are loitering to await their turn at a target. But they can
all engage at once if sufficient targets present themselves. If your UCAV
control link is limited to a half dozen planes concurrently you've opened
yourself up to saturation tactics.