US Sells Taiwan IRST

choi

(1)
(a) US Approves Sale to Upgrade Taiwan Warjets' Air Tracking. AFP, Aug 23, 2023.

three consecutive paragraphs:

"The State Department [today, Aug 23] said it informed Congress of the $500 million sale of F-16 Infrared Search and Track [IRST] systems and related equipment to help Taiwan 'maintain a credible defensive capability.'

"The sale will help Taiwan 'meet current and future threats by contributing to the recipient's abilities to defend its airspace, provide regional security and increase interoperability with the United States through its F-16 program.'

The new system, built by Lockheed Martin, improves fighter jets' ability to detect airborne threats, increasing the chances of F-16s' survival during combat.

Note: IRST21 or legion pod (which has additional functions, such as communication between legion pods of friendly warjets) is the most advanced by Lockheed Martin.  News report only said IRST to Taiwan but did not identify version.

(b) Only one news report speculates on which version of Lockheed Martin is sold to Taiwan.

Joseph Trevithick, Taiwan's F-16s Cleared To Receive IRST Targeting Systems; Infrared search and track sensors would greatly help Taiwan's F-16s detect and track threats, especially stealthy ones like China's J-20.The Drive, Aug 23, 2023 (in the "War Zone" section).
https://www.thedrive.com/the-war ... t-targeting-systems

Quote:

(i) " * * * This comes amid delays in the Taiwanese Air Force's acquisition of new Block 70 F-16C/Ds [which Trump approved in 2019, but years are needed before dfelivery], but the new sensor systems could also be used on its fleet of upgraded F-16Vs [V for viper, a version for Taiwan only].

(ii) "The DSCA [Defense Security Cooperation Agency within United States Department of Defense] press release does not specify what kind of IRST system, but does name Lockheed Martin as the 'principal contractor.' In 2019, Lockheed Martin displayed a model of a Block 70 F-16[C/D] with what appeared to be a podded IRST system on one of its chin stations at the biennial Taipei Aerospace & Defense Technology Exhibition in Taiwan that year.

"The same pod seen on the model at the exhibition in Taipei had appeared earlier in 2019 in promotional material, including the video below, for an advanced F-16 derivative, dubbed the F-21, which Lockheed Martin pitched to India.

"The pod seen on the model shown in Taiwan and in the F-21 marketing materials is visually distinct from Lockheed Martin's main current podded IRST offering, called the Legion Pod. The Legion Pod is actually a modular store that can be configured to perform various additional functions, including communications relay duties.

"It is possible that this other pod could use the same IRST system used on the Legion Pod, which is called the IRST21. That a version of this specific sensor family is also found on an IRST system in development for the U.S. Navy for use on its F/A-18E/F Super Hornets, which utilizes a modified drop tank [there is an en.wikipedia.org page for drop tank] .


(2)
(a) An IRST Legacy. Lockheed Martin, Aug 17, 2018.
https://www.lockheedmartin.com/e ... 17/irst-legacy.html

Quote:

"What is IRST?
"IRST is one way to detect and track objects that emit electromagnetic radiation – or infrared signatures. More simply put, it's a type of sensor system that can detect and track threats at long ranges. What makes it unique is its 'passive' nature – meaning it can act without emitting any radiation of its own. We call it a 'see first, strike first' sensor system because it enables aircrews to target threats, or adversaries, before those adversaries see (or sense) them.

"Why is this capability important? There’s no doubt that near-peer adversaries are advancing their targeting technologies, meaning risks for our airborne platforms are growing. With IRST, our aircrews can fly in threatening environments and engage adversaries without using radar, eliminating the risk of detection, jamming and electronic attack. By seeing first – and striking first – our aircrews increase their lethality and improve their survivability.

(ii) [Starting with US Navy's F-14D Tomcat in 1991, through IRST21 to 'Lockheed Martin's newest offering – Legion Pod – puts its most advanced IRST21 sensor system in a podded configuration' (Legion Pod contains IRST21, that is)] "Introducing IRST21[:]
"In the mid-2000s, Lockheed Martin was selected as the winner in the US Navy's F/A-18E/F IRST competition, which required 170 systems. Lockheed Martin's advanced offering – known as IRST21 – does more than provide situational awareness; it detects, tracks and ranges targets with weapon-quality accuracy.

(b) 5 Reasons IRST21 Is Revolutionizing The Battlespace. Lockheed Martin, Lockheed Martin, , July 8, 2021.
https://www.lockheedmartin.com/e ... he-Battlespace.html

three consecutive paragraphs"

"Infrared Search and Track (IRST) is an infrared sensor that gives pilots a fully passive air-to-air engagement, meaning it does not alert other aircraft of its presence while enabling offensive air engagements in an environment where radar isn’t an option. This capability is key to leveraging fourth-generation fighters in a fifth-generation battlespace.

"Lockheed Martin's IRST21® sensor provides passive lethality, meaning it allows pilots to see opposition aircraft and target them without being seen. This is made possible by the sensor seeing the heat signature – or “skin” – of an aircraft, which ultimately increases pilot survivability.

"IRST21 supports targeting solutions, such as the guidance of AIM-120C/D and AIM-9X [sidewinder]  missiles beyond-visual-range. This fully integrated solution complements other systems and sensors, making the entire weapon platform more lethal and capable while enhancing survivability for the warfighter.


(3)
(a) Forward-looking infrared
https://en.wikipedia.org/wiki/Forward-looking_infrared
("(FLIR) cameras * * * They can be used to help pilots and [car] drivers[, which is autopilot or driverless car is about] steer their vehicles at night and in fog, or to detect warm objects against a cooler background. The wavelength of infrared that thermal imaging cameras detect is 3 to 12 μm and differs significantly from that of night vision, which operates in the visible light and near-infrared ranges (0.4 to 1.0  μm).   Infrared light falls into two basic ranges: long-wave and medium-wave. Long-wave infrared (LWIR) cameras, sometimes called 'far-infrared,' operate at 8 to 12 μm and can see heat sources, such as hot engine parts or human body heat, several kilometers away. Longer-distance viewing is made more difficult with LWIR because the infrared light is absorbed, scattered, and refracted by air and by water vapor.   Some long-wave cameras require their detector to be cryogenically cooled, typically for several minutes before use, although some moderately sensitive infrared cameras do not require this. Many thermal imagers, including some forward-looking infrared cameras (such as some LWIR enhanced vision systems (EVS)) are also uncooled.   Medium-wave (MWIR) cameras operate in the 3–5 μm range. These can see [objects NOT as far as kilometers away] almost as well, since those frequencies are less affected by water-vapor absorption")

Note:
(i) The entire quotation applies to infrared imaging, not FLIR.
(ii) What is "Forward-looking" in FLIR? It just means looking ahead. With a wide-angle lens, the camera may see more in front, but not on the side or in the back.

(iii) Section 3 of this Wiki page mentions "push broom." Both push broom (a broom with wide flat, short broom which one pushes in front of him) and whisk broom imaging are active cameras, in that either types emit lights. One example of the former (push broom) is found in photocopier/ scanner (of a document or a photo). An example of the latter (whisk broom) is a barcode reader.

Click "push broom" in this Wiki page and you will see how push broom scanner works; watch the animation. Then watch the animation of whisk broom scanner
https://en.wikipedia.org/wiki/Whisk_broom_scanner
, which has only one (light) beam, instead of a row of beams. Both push and whisk brooms to detect infrared are older, active methods than passive IR detectors/ sensors.

(C) Google compiles:

"What is a whisk broom used for?

"Whisk brooms [because they look like whisks] are short, small brooms without handles that are made for cleaning tight spaces. They're designed for use with dustpans.


See also broom
https://en.wikipedia.org/wiki/Broom
("A smaller whisk broom or brush is sometimes called a duster")


(4)
(a) Thermal Infrared Imaging (FLIR) Explained. Infiniti Electro-optics, undated
https://www.infinitioptics.com/technology/thermal-imaging
("All objects warmer than absolute zero (-273°C/-459°F) emit infrared radiation in the MWIR and LWIR wavelengths (3µm–14µm) in an amount proportional to the temperature of the object [and are displayed in black-gray-white or color scales]. * * * In order to 'see' radiated heat, special lenses and sensors are needed * * * [for the latter (sensors)] FPAs (Focal Plane Arrays) are required. These can be divided into two types, cooled and uncooled detectors.   Cooled detectors exist to maximize detection performance. * * * Both our high-definition MCT (Mercury Cadmium Telluride or HgCdTe) sensors and our Indium Animonide (InSb) sensors incorporate a cryogenic cooling system to reduce the 'noise' from the heat of the internal camera components and the sensor itself. This allows for detection of thermal energy with an accuracy as fine as 0.025°C [but these cost money and are bulky]")
(b) James "Ralph" Teague and David Schmieder, The History of Forwards-Looking Infrared (FLIR). Defense Systems Information Analysis Center (DSIAC), October 2021.
https://dsiac.org/wp-content/upl ... -Monograph-FLIR.pdf


Quote:

(i) page 4-1: "It was not until the Vietnam War (discussed in Chapter 5) that passive, fast-framing imaging systems capable of viewing object self-emissions were developed.

(ii) page 4-8: "Later, when airborne Doppler ]active] radar became feasible, IRSTs and radars were integrated together to provide the advantages of IRST covertness with radar's low false-alarm rate, long range, and fire-control capabilities. The HAC AN/ASG-18 prototype airborne radar/IRST fire-control system was the first US pulse-Doppler radar system with look-down/shootdown capability. Pulse-Doppler radars have an advantage over passive IRSTs in detecting closing aircraft against ground clutter because Doppler signal processing effectively removes stationary objects. The radar range of the AN/ASG-18 was estimated to be between 200 and 300 miles with reliable detection of bomber-sized targets at 100 miles.

(iii) Figure 10-3 caption: "In a passive/active targeting system, the FLIR is used for passive target detection and the lidar is used for active identification. (Source: BAE, UK).

And the text before and after the figure: "Passive/Active Fused Sensors. Airborne and Naval platforms have taken an entirely different approach to gaining extended-range target identification. Their approach can, in principle, triple the range of existing targeting FLIRs. They are adopting passive/active hybrid systems consisting of passive IR imaging for target detection in combination with active lidar (light detection and ranging [which brings about the acronym lidar], analogous to radar as 'radio detection and ranging') for high-resolution identification. Figure 10-3 shows an example of this imagery provided by BAE. The principle is that lidars can image with much shorter wavelengths, near 1.54–1.57 µm, to greatly reduce the diffraction blur diameter of the optics with a corresponding increase in range. Moreover, this choice of wavelengths is eye safe.

(c) I wonder if IRST21 may see an approaching missile, not just an aircraft (plane or helicopter). And a stealth [;ane, which looks minimum in radar, may be detected with IRST21.