Pathfinder escribió:Víctor Demóstenes escribió:El DAS es el sistema de cámaras distribuidas en el F35, sobre todo pensado para detectar misiles. Funciona en MWIR y LWIR, pero no sirve para seguir cazas y apuntar.
Ya me he quedado en tu primer párrafo. Vas muy perdido, pero por bastante. 1 solo ejemplo, de que muchas de las afirmaciones que haces van sin fundamento alguno.
https://youtu.be/e1NrFZddihQY de salida, te recomiendo, este hilo.
viewtopic.php?f=5&t=4631
Bebes de fuentes publicitarias que no entran en el detalle. Piénsalo un poco: ¿Quieres decir que el DAS del F35 ofrece las mismas capacidades que el EOTS del F35? Algunas diferencias habrá, ¿no?
La función primordial del DAS no es apuntar. Su misión principal es de la ofrecer una conciencia situacional más amplia al piloto y la de detectar misiles entrantes. Para ello, su visión es de corto alcance.
A cambio, el EOTS situado al frente tiene es un FLIR con una óptica superior que permite varias aumentos, aparte de estar estabilizada y ofrecer, valga la redundancia, una mayor estabilidad en la imagen.
One extreme is F-35 with DAS and EOTS where the identification range for EOTS is probably longer than detection range of DAS. This is because DAS is very wide FoV (something like 95 degrees or more for spherical capability) sensor and EOTS has very narrow FoV (probably under 1 degree) like all modern targeting pods have.
https://www.f-16.net/forum/viewtopic.php?f=62&t=20536&sid=9e7460d76869efe8522c8e8537d95e1f&start=75¿Puedes apuntar con el DAS? Sí y no. Si el caza enemigo está cerca, puedes indicarla al misil la dirección a la que debe dirigirse. Pero si el caza enemigo está lejos, el DAS no te vale. Para eso tienes el EOTS. Por eso dicen que el DAS ofrece "cueing", que se traduce en "ponerlo sobre la pista", que no es lo mismo que dirigirlo:
DAS is comprised of 6 infrared sensors, with wide-angle lenses, that provide 360 degree spherical coverage (to detect and track incoming missiles, track enemy vehicles at short or medium range, etc).
Lastly there’s also just the optics to consider; they’re functionally the same in that they focus light / heat from a certain field of view onto the FPA, but your average handheld thermal camera (and also the DAS on the F-35) have fairly simple lenses that are fixed or have limited zoom functionality. They also generally have no stabilisation or only minor shake-reduction stabilisation. The F-35’s EOTS (and similar targeting pod systems like the SNIPER, LITENING, ATFLIR, etc on other jets) meanwhile can have extreme levels of magnification they can achieve a ballpark equivalent of a 2,000mm focal length with their lenses; high-end consumer cameras generally only get up to around 500mm.
https://www.quora.com/What-are-IRST-sensors-used-by-the-US-Air-Forces-F-35-stealth-fighter-and-how-are-they-different-from-common-thermal-camerashttps://www.f-16.net/forum/viewtopic.php?f=62&t=20536&start=15DAS will not be able to do accurate ranging besides short ranges (basically visual range) as it has very wide field of view (over 90 degrees) and even with very high resolution sensor can not get enough pixels from targets from longer range to do accurate ranging. Of course for longer ranged ranging and identification there is always EOTS.
"Cueing" o "poner sobre la pista", eso es lo que hace el DAS. Pero no da información de distancia para obejtivos lejanos (el EOTS, sí):
DAS could provide a boresight to the AMRAAM into the target's general direction.
https://www.f-16.net/forum/viewtopic.php?f=55&t=53816Si miras la infografía en esa misma página, verás que dice que el DAS ofrece "
short range missile targeting". A eso me refería conque no sirve para apuntar (a objetivos lejanos en un combate BVR).
Of course knowing the target's range is very important (for an AMRAAM launch) since it will indicate where and when the AMRAAM should turn on its onboard radar and thus becoming much more effective (which a much higher hit/kill probability) than otherwise.
Más luego tienes que el F35 está pensado como minibombardero más que caza de superioridad aérea. Por eso lleva el EOTS debajo del morro. Y eso , que es perfectamente viable para ataque al suelo, lo limita para ver cazas que vuelen más alto que él (y los cazas de superioridad aérea suelen hacerlo):
https://www.quora.com/Why-does-the-US-Air-Forces-F-35-stealth-fighter-use-an-IR-sensor-bubble-with-flat-faces-under-the-fuselage-instead-of-a-ball-shaped-sensor-in-front-of-the-canopy-like-Russian-and-European-fighters
https://www.f-16.net/forum/viewtopic.php?f=62&t=20536&sid=f510456819e847631ecfc223f18d4c8e&start=30I'm pretty sure that FSO IR channel is LWIR as that gives best performance for long range detection at high altitudes given the likely technology used. EO DAS and EOTS use MWIR as that's superior in all other ways (like ID, targeting and so forth). In FSO - is used for ID.
Ahí lo tienes una vez más. Está más pensado para el ataque al suelo y el combate aéreo cercano (conciencia situacional), que para un combate desde lejos. El LWIR que incorpora el Tifón te permite detectar mejor cazas relativamente lejanos en base a su rozamiento con el aire frente al cielo frío.
Otra referencia más:
Here is a different approach to Infra-Red sensors. The JSF has a superb Electro-Optical Distributed Aperture System (DAS) designed to cover the sphere around the aircraft, but strongly optimised for air-to-ground operations. The Su-35S has a large aperture OLS-35 IRST optimised to scan for other aircraft at long range in its area of interest. DAS is a ‘staring array’ while the OLS-35 is a ‘scanning array’. The difference in detection range is like the difference between a person searching with a naked eye compared with another searching with a telescope. If the telescope is pointed in the right direction, it will get first detection.
http://www.ausairpower.net/APA-NOTAM-05072010-1.htmlhttps://www.f-16.net/forum/viewtopic.php?f=62&t=20536&sid=2346a37455eb2d7aebb574b7d0963857&start=45With EODAS and EOTS we are talking about MWIR detectors and that gives quite different imagery from LWIR detectors (which FSO IR channel very likely uses). You can not really compare the images of different wavelengths directly. MWIR cameras have peak emission at relatively high temperatures and therefore the it can be better for the detection of jet exhaust or jet plume signatures with high thermal contrast against ambient temperatures. LWIR on the other hand has the peak emissions at approximately room temperature which means it can detect colder objects better especially against cold sky background.
https://www.f-16.net/forum/viewtopic.php?f=62&t=20536&sid=8f6f09f11247fbbcdc210d31a9cae0b6&start=60On the other hand F-35 DAS is very useful short range IRST system and can detect and track a lot of targets that are close to the aircraft or have high thermal signature (like those rockets it has tracked over thousand kilometer away). But it can't see aircraft or cruise missiles beyond what naked eye can do in good conditions
http://www.ausairpower.net/APA-JSF-Analysis.htmlThe JSF's Electro-Optical Sensor System (EOSS), comprising the ventral Electro-Optical Targeting System (EOTS) and spherical coverage Distributed Aperture System (DAS). The EOSS is primarily aimed at close air support and lower altitude battlefield interdiction roles, a result of US Air Force and Marine Corps inputs to this traditionally dangerous regime of operations.
http://www.ausairpower.net/APA-NOTAM-300309-1.htmlThe ‘shooting match’ shifts from radar-centric to ‘infrared centric’. The problem here is that the PAK-FA will have it, the F-22A does not, and the ability of the F-35 EOTS and DAS to make long range aircraft detections and guide weapons is at best ‘unproven’. The F-35 systems have not been designed to be highly sensitive at the task of searching and tracking distant aircraft at those infrared colours where aircraft and their jet engines emit most of their infrared energy.
Fights between the F-22A and the PAK-FA will be close, high, fast and lethal. The F-22A may get ‘first look’ with the APG-77, the Advanced Infra Red Search and Track (AIRST) sensor having been deleted to save money, but the PAK-FA may get ‘first look’ using its advanced infrared sensor. Then, the engagement becomes a supersonic equivalent of the Battle of Britain or air combat over North Korea.
http://www.ausairpower.net/APA-NOTAM-300310-1.htmlNumber 3 of the F-35C sweepers gets a contact from his APG-81 radar, and the four inbound bogeys are shown across the network. Analysis of signals from the bogeys identifies them as Russian built Su-35S, previously seen moving on Woody Island by satellite recon. All the F-35Cs arm their four AIM-120D missiles and prepare for a ‘turkey shoot’, expecting to get ‘first-look, first-shot, first kill’. ‘Ah’, thinks Charlie, ‘this will be like the AN/AAQ-37 EO DAS advertisement: ‘manoeuvrability is irrelevant …let the missiles do the turning’.What Charlie Brown doesn’t realise is that such marketing hype was only partly right.
Siento que te hayas sentido ofendido porque haya puesto en duda las capacidades del extraordinario F-35. Pero la próxima vez, si criticas a alguien con semejante vehemencia, por favor, aporta como referencia algo más que un vídeo publicitario de Lockheed y contrasta diferentes fuentes.