AN-ASG-14
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Transcript of AN-ASG-14
Nowy_Szablon_Domylny
AN/ASG-14 radar fire control system Source: Internet Editor: Author: Time :2004-03-29 big middle small
Name Search ranging radar
Institutional pulse
Band X
Research and development unit RCA, General Electric
Equip time in January 1958 the United States Air Force's equipment
F-104A, the same year in October improved equip U.S. Air Force
F-104C tactical
Equipment model F-104A / C, T-39B
With weapons M-61 (T-171)-type "Vulcan" style six gun, AIM-9B
"Sidewinder" air to air missiles, AIR-2A "monster" empty nuclear
rockets
Working condition searches, distance tracking, electronic
resistance Technical Features The radar is AN/ASG-14 fire control
system. System consists of an optical gyro gunsight, ranging
airborne search radar, infrared detectors, which mainly used for
air to air interception. System can only be used in case of good
weather, but only with "front tracking" and "pure track" approach
to target.
Search ranging radar system is mainly used to search for the target
and the distance to the target sight input data and the target
position data from the look is displayed in a display. ASG-14 radar
can not automatically track angle, targeting and manipulation arms
fire. ASG-14 system has three operating states: search state,
distance tracking status, electronic warfare state. Systems with
ASG-14 F-104 aircraft, the intercepting aerial targets, it usually
take off from the ground and receiving radar vectoring, where the
airspace to reach the target by the ASG-14 radar in the airspace in
front of 90 conical helically scanning, search target. When the
aircraft 16 kilometers away from the target, the pilot pressed the
switch on the control column tracking, radar tracking into the
state where the antenna beam fanning airspace done at 20 conical
scan. ASG-state electronic countermeasures system, also known as
homing state radar transmitter does not work, the radar as a source
of electrical interference directed seeker. Homing state, the
antenna scanning and display sweep depends on the "homing" in which
the switch is turned on before the radar working condition. If the
track is connected to the former state, the antenna remains conical
scan; when the system is turned on before the search state, the
antenna remains helical scan. Display on the screen only shows the
source of interference, and can only determine its position.
Performance data Operating Frequency 9000 ~ 9600MHz (Airborne
magnetron tuning)
Transmit power 140kW (peak)
PRF 1000 25Hz; tracking state 1300Hz
Pulse width Search Status: 1s; tracking status: 0.5s
Form of a parabolic reflector antenna antenna aperture
approximately 70cm
Beamwidth Search: 3.9 cone beam tracking: 3.9 10 fan beam search
distance 37km
Search 90 cone in front of the aircraft search methods helical scan
scanning speed of 90 cone helical scan done when 550r/min, scan
cycle 3s
Tracking Distance 18.5km
Tracking range 90 cone in front of the aircraft tracking mode
conical scanning (azimuth no automatic tracking)
Relative velocity range 740 ~ 2965km / h
Display Type search: PPI; tracking: distance ring, relative speed
receiver sensitivity 96 ~ 106dBmW
IF 30MHz
IF bandwidth of 2.5MHz
Weight 77kg
Using height 21340m
Adapt to the temperature -54 ~ +71 Extension Overview Electronic
synchronizer a radar modulators, transmitters a waveguide assembly
a set of radar diplexers, 1 set of radar antenna mixer IF amplifier
1 a self-frequency modulation amplifier a distance calculator
displays a range and bearing 1 (ASG-14TI of 2)
Low power a motor servo drive components 1 Reference material
"AFM", 1969. The ASG14 was a very simple set even
compared to the to the E4(F86D). It used a spiral scan about a
fixed
axis about 3 degrees (I think) below the aircraft waterline. In
search
the entire antenna dish and feedhorn assembly was spinning about
100
rpm and slowly 'opened up' from dead center to 45 degrees off
boresight.
That took about 3 seconds. Then it snapped back to center (the
test
bench seemed to jump) and the cycle repeated. The max range on the
scope
was 20 n.m. If you picked up a target the blip was a small segment
of an
arc if it was 45 off axis, the length of the arc increasing as as
the angle
off axis decerased until when it ws on axis the blip became a
complete circle.
There was no angle track capability at all; the pilot did that by
flying the
104 to point at the blip. Once inside 10nm the pilot could lock on
in range
only by depressing the radar ranging button on the stick. The
antenna stopped
its diverging scan and simply spun about the boresight axis. The
pilot could
position a range gate over teh target and once locked on the set
fed radar
range to the gunsight's ballistic computer. A needle in a gauge at
the bottom
of the scope indicated overtake. The sight reticle would indicate
range in nm
if missiles were selected, 1000s of feet if guns were selected. The
radar was
tunable to combat ECM and also had a tunable ECM HOME function
where it was in
receive-only. (This did work quite well on B52s and EB57s) There
was also an IR
sight - that hafmoon window at the base of the armored windshield -
that used a
scanning system like a Nipkow disc TV set of the early days. There
were 2 spinning
discs, one with an arc shaped slit running one way, the other with
a reverse arc.
If there was no target out there, the senstive CdS (I think)
element's output was
cut off by an AGC-like circuit. But a spot IR target would result
in a momentary
signal and that, amplified, would flash a neon bulb. The resulting
flash would be
foucssed through a pair of similar synchronised spinning discs and
that output was
reflected off the gunsight combining glass. The resulting 'arced
cross' was visible
to the pilot and he flew the aircraft to put the pipper on the
cross. The range was
adequate for guns, around 3-4000 feet. As simple and as crude as it
sounds, it worked!
The AIM9Bs were boresighted along with the radar and the gunsight.
I got to shoot at
a Firebee once and I was tracking the drone strictly on radar. When
I got a mile
behind it I called "Flares" and seconds later heard the buzzing
growl in the missile.
I looked up through the sight and the pipper was on the flare. The
missile then knocked
the flare off its mount. (The warhead was clipped to save the drone
- #2 got the other
flare and #3 got the drone itself.
All in all the ASG14 was a simple reliable and effective weapons
system - it's
simplicity was enabled by the 104's ability to catch anything it
was after.
After exepriencing the slavery required to maintain an F86D/E4 and
then the F102's
MG10 with its incessant need for WSEM (missile system) testing the
104/ASG14 was a real
treat. Imagine changing the radar package in 20 minutes! And
aircraft availability
averaged over 90%! What a change from even the F102! The F86D/E4
and the F102A/MG10 both had nutating feedhorns.
It was easy to tell from the scope when the nutation motor wasn't
spinning because
the jizzle band was now a narrow line, as in ground map, when it
didn't spin anyway.
In the F104A ASG14 system the pilot did the angle tracking. I was
wrong when I
said the feedhorn tilted with the dish; it sat still as the dish
tilted and spun.
The pilot flew the airplane toard the blip. The blip would extand
in arc until it
formed a complete circle. The aircraft was then pointed -
boresighted - on the target
and the pilot applied as much power as was needed to close to
ID/firing range. To repeat,
the system did not lock on in angle, only range, and that for
overtake and weapons firing
range purposes. It was simple, reliable and effective. Excellent
example of KISS.
BTW it was also simple enough so that the sophisticated ECM gear
was pretty ineffective
against it. I flew some tests against 'fancy' stuff and all it did
was put some clutter on
the scope. Certainly the only thing it really did to us was confirm
the 'hostility' of the
target. (No, we didn't get to shoot; SAC wouldn't have liked
it)
His fancy electronic devices put a few flecks on our scopes but didn't particularly bother us and we deduced from what we could see that our 1956 ASG14 radars were not sophisticated enough to be bothered. I don't know how familiar you are with RCA's ASG14 but it's a modern analog to the RAF's AI Mk 8 used in WW2. Basically it is a spiral scan search radar with no angle track capability. Very simple in construction and operation; just find him on the 20-mile (max!) scope, turn toward him to fly him to the center and go get him. He'll show up as a small arc on the scope when he's 45 degrees off the nose in the turn. You know when he's dead ahead (on boresight) because then he paints as a circle around the center of the scope - the circle's radius is his range. The set can, however, lock on and track a target in (only!) range from 10 miles on in. Press a button on the stick grip and the antenna reverses direction and generates about a 10 degree conical scan. The pilot has to keep the target centered by flying the airplane, as I said, since there is no angle track capability at all. It does, when locked on, feed range to the computing gunsight; effectively, too. Range numbers show up on the sight; in miles when missiles are selected, feet when guns are selected. Handily, the Sidewinders look right along the same axis and will growl when they see the target. By the way, live harmonization proved the Zipper's M61 20mm Gatling gun had a meager dispersion of only 3 mils. It was electrically driven firing belted ammo so 'only' fired 67 rounds per second.