AESA elements counting by Japanese(so terrible)

[taog]

I've done some calculations about the potential capabilities of APG-81 in relation to raw detection range. If we assume that the pictures of APG-81 T/R module count are correct (well over 1600 modules) and if we assume it uses the best publicly known and marketed GaAs T/R modules (about 16W), we get some impressive numbers. We have to remember that it could well use even more powerful modules as they are available. 25W modules are sold already and even more powerful ones are in development. Even with 10W modules (that became available more than 15 years ago), it'd be very powerful radar set.

With 1676 modules and 10 W power each, giving almost 17 kW peak power with 700 mm antenna diameter (assumed to be perfectly circular), I've calculated that the conservative maximum detection range estimate would be about 360 km or almost 200 nmi against 3 m^2 target. With 16W modules this increase to slightly over 400 km. If the antenna area is larger, then it would give somewhat better range. 800 mm diameter would give about 450 km range with 16W modules. If we calculate the upper boundary of detection with 1676 16W modules and 800 mm diameter antenna with current tech LNA (low noise amplifier) used in receiving path, we get maximum detection range of about 550 km. So we get detection range of 360-550 km for 3 m^2 RCS target depending on antenna diameter and T/R module power and losses. Against 0.1 m^2 target detection range would be between 160 and 240 km. Against 0.001 target it would be between 50 and 75 km.

All these are of course using only single very high power radar beam to search for long range targets within a limited search area or areas without any restrictions. Using multiple beams or using very wide search area or using LPI waveforms is likely to shorten the detection range. But it could still theoretically search for the whole radar field of regard to 250-400 km range depending on exact performance figures and scan time.

All in all this shows very much that the APG-81 is likely going to be extremely powerful and versatile radar set. In air to air combat, it's very likely it's going to see other fighters well before they can see it. It can detect latest 4th generation fighters with reduced signatures (like EF Typhoon, Dassault Rafale or SH) at significant ranges (about 200 km away) even when they are almost clean. Those 4+ generation fighters would be able to detect F-35 at significantly shorter ranges, 50 km or less even with very good AESA radars. That alone gives F-35 (and F-22) a huge advantage in aerial combat.

1.i ask someone who study radar,he say APG-81/80 use different radiator than others like 77/79,the "unit" is the red circle in the below picture. But he say even counting in this way, APG81's elements amount still >1600(i count again,APG81 change to 1628 elements,80 change to 974 elements)

2.F35 's antenna size be considered as >=F18,which with 720~730mm diameter
3.yeah,Irbis-E 's 90km long detection with RCS=0.01 target is based on reduce the search volume → rise the dwell time to enhance its range
4.update the newest report about AFAR-X:it has 1526 elements,will be tested onT-50-5 ,achieve the expected ability with air-air and air-ground mode ,but"like other new system,there still some problems wait to be solved"

http://vpk.name/news/108050_umnaya_obsh ... ak_fa.html

[taog]

different pattern of radiator. APG81 use the right sample

[spazsinbad]

The image above does not show (perhaps not able to be hotlinked? dunno) so here it is (edited): http://i2.hoopchina.com.cn/blogfile/201 ... 94*162.jpg

[disconnectedradical]

One more image of the -81 from Key Pub's F-35 special (which I would recommend).

[doge]

From the renewed JPO official website www.jsf.mil.
https://www.jsf.mil/f35tech

Active Electronically Scanned Array
The F-35 radar system has an active, electronically scanned multi-function array (MFA) and the RF support electronics necessary to support a fully functional radar. It also has integrated radar software modes that are hosted on the integrated core processor.
The radar operates through the nose radome, which has a wide bandwidth, enabling high-power transmissions over a large frequency range.
Reliability:
AESA’s solid-state technology and elimination of mechanical moving parts will enable the radar to far surpass current standards for systems reliability. The radar system also features a “replaceable assemblies” design for faster, easier repairs or upgrades to hardware and software modules. For these reasons, AESA life-cycle costs are expected to be significantly lower than those of mechanically steered arrays (MSA). The active arrays on the F-35 should have almost twice the expected life of the airframe.

AN/APG-81 has 1,676 GaAs T/R modules and likely the most advanced fighter radar ever.

Is that released number a numbers that is okay if the JPO officially write opens it to the publish !?!?

Other excerpts. (The pages of ALIS/ODIN, DAS, EW, EOTS, Stealth was not interesting to me because it was many of words I had seen somewhere before.)

Sophisticated Cockpit
The F-35 provides its pilot with unsurpassed situational awareness, positive target identification and precision strike under any weather condition. Mission systems integration and outstanding over-the-nose visibility features are designed to dramatically enhance pilot performance.
The F-35's cockpit has:
A 20- by 8-inch glass cockpit touchscreen
An Adacel cockpit speech-recognition system, a first for an operational US fixed-wing aircraft

Diverterless Inlet
The F-35’s diverterless inlet lightens the overall weight of the aircraft. Traditional aircraft inlets were comprised of many moving parts and are much heavier than newer diverterless inlets. The diverterless inlet also eliminates all moving parts.
When an aircraft is flying, the speed of the air relative to the engine is equal to the plane’s flight speed. However, current turbine engines are unable to handle supersonic airflow. This is because shock waves associated with supersonic speeds can damage or cause dangerous vibrations in turbine blades, resulting in loss of thrust or engine failure.
Consequently, in aircraft travelling at supersonic speeds, the air entering the inlet must be slowed down to subsonic speeds before reaching the compressor and turbine blades of the jet engine. Additionally, the airflow must also be at the optimal speed and volume to achive maximum thrust.
The DSI bump design functions as a compression surface and creates a pressure distribution that prevents the majority of the boundary layer air from entering the inlet at speeds up to Mach 2. In essence, the DSI does away with complex and heavy mechanical systems.

HMDS Helmet Mounted Display System
In lieu of a physical Head-up Display (HUD), the F-35 uses a Helmet-mounted Display (HMD). The F-35 is the first modern fighter to use an HMD to the exclusion of a HUD. The HMD projects two identical images onto the visor, one for each eye, focused at infinity.
HUD vector symbology as well as sensor video is projected onto the visor. One of the most interesting sensors on the aircraft is the Distributed Aperture System (DAS). Surrounding the aircraft are 6 staring infrared cameras which are sensitive to thermal radiation.
The video processing computer seamlessly stitch the F-35 Lightning II Cockpit individual images together into a 4π steradian sphere for the pilot to look through. As the pilot positions the helmet line of sight the appropriate portion of the imaged sphere is projected onto the visor. This makes it possible to “look through the aircraft structure”. Because the cameras are located external to the cockpit pilots have remarked that “it is like flying Wonder Woman’s glass airplane.” This capability is extremely useful when trying to position the aircraft from a hover over the landing spot.
Revolutionary situational awareness: The next-generation user interface serves as the pilot’s primary display system, and virtual capabilities enable them to see through the bottom of the fuselage or directly at a target.
With an uninterrupted display of flight information and sensor data, the pilot experiences extreme spatial orientation, superior weapons targeting, and tactical superiority–both day and night.​