What's new

Embraer Develops platform for DRDO AWACS ,20 more to be ordered

Actual AWACS system don't use rotodomes anymore, because the AESA radar beam can be steered to up to 150°. Our A50 Phalcon uses 3 radar arrays placed in a triangle form, which means the beam moves around the aircraft, from one array to the other and not the whole dome.

E3 with rotodome and 2 radar arrays:

The E-3 AN/APY-2 has a single array not two, the other side houses the MK-XII IFF antenna.

"AWACS systems don't use rotodomes anymore"?

The Hawkeye E2-D comes equipped with a rotating AESA and is the only airborne AESA radar known to operate in a hybrid mode - electronically steered and mechanically rotated at 4 to 6 rpm.
 
The E-3 AN/APY-2 has a single array not two, the other side houses the MK-XII IFF antenna.

"AWACS systems don't use rotodomes anymore"?

The Hawkeye E2-D comes equipped with a rotating AESA and is the only airborne AESA radar known to operate in a hybrid mode - electronically steered and mechanically rotated at 4 to 6 rpm.

Thx for the correction with the E-3 radar, but I wasn't wrong that actual AWACS systems don't use rotodomes anymore. The E-2D is just an upgraded older AWACS aircraft, not a new developed like the G550 Phalcon, the Boeing Wedgetail, or even the V 22 Osprey AWACS that was proposed from Boeing:



The advantage of AESA radars makes a rotodome not necessary anymore.
 
Thx for the correction with the E-3 radar, but I wasn't wrong that actual AWACS systems don't use rotodomes anymore. The E-2D is just an upgraded older AWACS aircraft, not a new developed like the G550 Phalcon, the Boeing Wedgetail, or even the V 22 Osprey AWACS that was proposed from Boeing:

The advantage of AESA radars makes a rotodome not necessary anymore.

I didn't say you were wrong, I merely highlighted an exception. You are right about the E-2D being an enhanced design but all things considered the designers choose to retain mechanical rotation despite the added weight, cost and maintenance overhead - why? Considering 360 deg coverage isn’t the triangular antennae à la Phalcon a better choice? Well for one thing, I’m not sure the smaller airframe can support a triangular antennae when you consider the additional cooling and processing hardware needed to support two additional array. Further the Phalcon’s triangular antennae suffers from diminished performance due to “own ship orientation” the mechanical rotation of E-2D is able to overcome this limitation introducing other problems. You see people who design antennae’s know there are limitations and trade-offs with every design.

And yes, the Osprey AWACS is just a concept, the attenuation caused by the large propellers makes the Osprey an unlikely choice for future AWACS. I think with advancements in solid state electronics and with smaller, cheaper and more powerful COTS the F-22 could easily be the AWACS platform of the future.
 
Further the Phalcon’s triangular antennae suffers from diminished performance due to “own ship orientation”
the mechanical rotation of E-2D is able to overcome this limitation introducing other problems

Can you explain those lines plz. Esp the highlighted Terms
 
Last edited:
I didn't say you were wrong, I merely highlighted an exception. You are right about the E-2D being an enhanced design but all things considered the designers choose to retain mechanical rotation despite the added weight, cost and maintenance overhead - why? Considering 360 deg coverage isn’t the triangular antennae à la Phalcon a better choice? Well for one thing, I’m not sure the smaller airframe can support a triangular antennae when you consider the additional cooling and processing hardware needed to support two additional array.

Imo it was simply a cost factor, developing and integrating an new dome for the E-2 would have cost way more, than simply upgrading the older dome to AESA.
Regarding the triangular antenna on smaller aircrafts, I am not an expert in this, Sukhoi is developing an UAV with such an antenna, so it should be possible:

zond-1.jpg



Sukhoi Company (JSC) - Airplanes - Projects - UAV


And yes, the Osprey AWACS is just a concept, the attenuation caused by the large propellers makes the Osprey an unlikely choice for future AWACS. I think with advancements in solid state electronics and with smaller, cheaper and more powerful COTS the F-22 could easily be the AWACS platform of the future.

Can you explain the problem with V22 as a platform a bit more, because imo India would be a perfect development partner for Boeing for the AWACS version. It is the only platform that could be fielded on the IN STOBAR carriers, as well as on future CATOBAR carriers and offers a comparable performance as the E-2.

E-2:
# Maximum speed: 375 mph (604 km/h)
# Range: 1,605 mi (2,583 km)
# Service ceiling: 30,800 ft (9,300 m)

V 22:
# Maximum speed: 250 knots (460 km/h, 290 mph) at sea level / 305 kn (565 km/h; 351 mph) at 15,000 ft (4,600 m)[113]
# Range: 879 nmi (1,011 mi, 1,627 km)
# Ferry range: 1,940 nmi (with auxiliary internal fuel tanks)
# Service ceiling: 26,000 ft (7,925 m)

With possibly 3 - 5 carriers (2-3 aircrafts per carrier), IN could be the biggest operator behind the USN for such aircrafts.
 
I remember Indian Navy was given a demo of V22 , bottleneck of catapult was hampering the E2C which were rejected outright , then E2D was offered and this whole shore-based thing came up .
V22 was covered in India-Defence article I remember , let me search for it . It would be better suited for our Sky-Jump type carriers

As far triangular thing is concerned , it must have been heating issues with array nothing else , I dont see preference of Mechanical scanning over Electrical one .

If E2D is upgraded designed platform what is hampering putting a bigger radome on it , cost with USN i dont think so
 
^^^^^^^ He was referring V22 AWACS is not operational , not SAAB
 
Can you explain those lines plz. Esp the highlighted Terms

Sure, but I'm going to steal shamelessly from Gambit to explain "ownship orientation"

Now read this...

Ares Homepage

As the main beam is move towards an edge, on either side, the main beam will begin to compress the many smaller lobes as they have nowhere to go. Here is a good illustration of this physical limit...

RADAR *RESOLUTION

In addition to the main beam, antennas produce rays of energy called sidelobes, which surround the main beam (primary lobe) like haloes (fig. 2-12). Sidelobes extend outward only a short distance from the radar and contain very low power densities. However, even though they are weak, sidelobes can detect strong non-meteorological targets near the radar and are also disturbed by nearby g-round reflections. This leads to confusion in interpreting close targets because sidelobe targets are displayed along with the main beam targets.

Main beam performance remain valid within 120deg of scan angle, meaning target information that is detected by the main beam are clearly resolved to the system's best parameters. Outside of that 120deg and the wave superposition principle begins to have a negative effect on that performance. The sidelobes have nowhere to go but into the main beam. So if you wish, for the benefit of interested readers, from the center of each array, draw a 120deg corner to illustrate this scan limit. Then draw and overlay another corner with 140deg to illustrate the maximum limits where target ambiguity begin to induce serious doubts for the system.

Personally, 0.2 meter clearance is too little for the array from the radome. Wings under aerodynamic forces can flex to around a meter, or more for the B-52's wing span. The radome will not flex but it will have some movement as well as vibration.

http://www.defence.pk/forums/milita...-system-deal-pakistans-likely-response-5.html

...due to "ownship orientation" targets that occur in the areas outside of 120 deg "best parameter" zone may not be detected due to diminished range or resolved accurately - multiple bogeys may appear as one. To get a better read on these targets the ship(Phalcon) will have to reorient itself so that targets occur in the 120 deg "best parameter" zone. On the E2-D, the array can be mechanically rotated to cover the area of interest but it does leave a huge blind spot on the opposite side.
 
Can you explain the problem with V22 as a platform a bit more, because imo India would be a perfect development partner for Boeing for the AWACS version. It is the only platform that could be fielded on the IN STOBAR carriers, as well as on future CATOBAR carriers and offers a comparable performance as the E-2.

E-2:
# Maximum speed: 375 mph (604 km/h)
# Range: 1,605 mi (2,583 km)
# Service ceiling: 30,800 ft (9,300 m)

V 22:
# Maximum speed: 250 knots (460 km/h, 290 mph) at sea level / 305 kn (565 km/h; 351 mph) at 15,000 ft (4,600 m)[113]
# Range: 879 nmi (1,011 mi, 1,627 km)
# Ferry range: 1,940 nmi (with auxiliary internal fuel tanks)
# Service ceiling: 26,000 ft (7,925 m)

With possibly 3 - 5 carriers (2-3 aircrafts per carrier), IN could be the biggest operator behind the USN for such aircrafts.


The V22 airborne radar was a concept that was first introduced at Farnborough airshow in 1990, nothing has happened since then.

The large propellers on the V-22 will cause multipath interference this means that transmission from the radar is reflected back to its own receiver by the large propeller blades producing noise. Of course, all propeller propelled airborne radar experience this phenomenon and the noise is filtered out - but on the concept V-22 due to the very large propeller all transmissions from the forward facing array will be affected.
 
Last edited:
The V22 airborne radar was a concept that was first introduced at Farnborough airshow in 1990, nothing has happened since then.

The large propellers on the V-22 will cause multipath interference this means that transmission from the radar is reflected back to its own receiver by the large propeller blades producing noise. Of course, all propeller propelled airborne radar experience this phenomenon and the noise is filtered out - but on the concept V-22 due to the very large propeller all transmissions from the forward facing array will be affected.

Yes they were offered to the UK, for their new carriers, but they rejected it because of the high costs and chose the AEW version of their AW 101 helicopter instead. However, I never read about technical issues for the rejection, only about costs.
 
Going thru Kinetics post on DRDO and ADA secs earlier , i went to DRDO website to conform that . Guess what I fond - New DRDO pdf newsletter . And the best thing was this below , I was always doubtful of Datalink and Satcom capability of DRDO.


DRDO develops SATCOM datalink for Airborne Early Warning and Control (AEW&C) System

Ku-BAND.jpg

Airborne Early Warning and Control (AEW&C) System is a force multiplier being designed and developed by DRDO, with the Centre for Airborne Systems (CABS), Bangalore, as the nodal agency for the program. Airborne Early Warning and Control System is a system of systems consisting of multiple sensors for surveillance, and signal intelligence and electronic warfare and is based on a modified EMB-145 executive jet.
The data from all the sensors are integrated at the Mission System Controller and presented to the onboard operators for situational awareness on multiple reconfigurable Operator Workstations. The AEW&C system aids the operator in fighter control missions for support in air defense operations and has the capability to communicate with the fighters over V/UHF data-links. The recognizable air surveillance picture is communicated to the ground command and control network of IAF using line-of-sight (LOS) data-link in C-band and beyond LOS Satellite Communication (SATCOM) link in Ku-band.
An airborne SATCOM datalink has been designed and developed for the first time in the country as part of the AEW&C Programme by Defence Electronics Application Laboratory (DEAL), Dehradun, a constituent laboratory of DRDO, based on the requirements provided by CABS. The hardware for the Base Band Unit (BBU) has been configured based on the commercial off-the-shelf (COTS) solution evolved by CABS. The solution meets the requirement of providing commonality in hardware between various sub-systems of AEW&C providing better inventory management facility to the user. CABS has also evolved the most suitable form factor for all LRUs taking into account the space constraints of the aircraft. Packaging of the sub-system units has also been done accordingly. The design is based on the Ku-band transponder of geostationary satellite (GSAT-2), which has a footprint covering the main-land of the Indian subcontinent. The operational requirements include capability of air-to-ground communication with a data-rate of 64 kbps in full duplex mode including two voice channels. Copyright@DRDO Technology Focus.

Download link -
http://www.drdo.com/pub/techfocus/2010/jun10.pdf
 

Back
Top Bottom