Dear LordAssap/Fonk/Sampaix/Dare2/Whatever (:diablo::p:D), glad to have you back! It’s been ~ 1/2 year and frankly we missed you… you bring the funny side to this forum
A very good way to distract pple from the fact that you have no proper technical point to oppose to the links i posted.
Just to educate you: “adding bandwidth” won’t “give you increased range in adverse conditions”.
Yes it does; only YOU doesn’t know it yet.
Posted 05/17/07 17:44
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Seeing More Infrared
French Firms Develop Bispectral Sensors for Air, LandBy PIERRE TRAN, PARIS
French industry is developing infrared sensors that see in two bandwidth groups, an effort to fill military requests for gear that can penetrate camouflage, smoke, fog and other difficult conditions.
Most gear now sees in only one segment of the infrared spectrum, which is often divided into three bands: short-wave, 1 to 3 microns; medium-wave, 3 to 5 microns; and long-wave, 8 to 12 microns.
Each set of wavelengths has its operational advantages and disadvantages.
“There has been internal debate on what’s the best spectrum to use,” said Michel Papuchon, technical director of the Thales Land and Joint Systems division.But with military users constantly pushing for smarter, more capable technology, suppliers are developing products that will help to acquire and identify objects more effectively in shifting operational conditions.
So Thales and other firms are working on gear that is sensitive to infrared energy in more than one band.
This bispectral approach promises sensors that reveal different aspects of the same object, allowing the user to see things clearly that a single band may show only in weaker resolution.
Images taken from two parts of the wavelength could also be fused to create a synthetic picture, the optical equivalent of synthetic aperture radar.
Using two parts of the spectrum means the camera can also be effective in different climates, as hot or cool temperatures can cut the effectiveness of a single-band sensor, depending on the wavelength.
In a bid to have their cake and eat it too, Thales optronics engineers have produced a technology demonstrator camera, dubbed the Catherine XP project, that works in the medium- and long-wave bands.
Based on technology for the existing Catherine series of fire-control sensors, the demonstrator was completed in March after a year’s work and unveiled at a sensor technology conference in Orlando, Fla.
The camera uses third-generation gallium arsenide sensor technology and projects an eye-safe laser beam, Papuchon told journalists.
The Catherine XP includes two Quantum Well Infrared Photodetector arrays — one per band — to provide an image of 768 by 575 pixels, according to an article in a 2006 issue of Proceedings of SPIE, the International Society for Optical Engineering.
The arrays occupy a housing about the size of two small laptop computers stacked one atop the other, the same size as a single-band model.
Thales intends next to develop a more advanced demonstrator model whose array can sense both wavelength bands at the same time.
Applications range from UAVs and other aerial platforms to a turret-mounted sight on light armored vehicles.
Thales developed the dual-spectrum Catherine XP camera with the Délégation Générale pour l’Armement procurement office and Sofradir, a French infrared sensor specialist.
Sofradir has also gone the bispectral route, developing the Janus compact infrared detector to work in the short- and mid-wave bands.
Designed for air-to-air missiles and missile-warning systems, the sensor uses its multispectral abilities to distinguish between jet engines and decoy flares, said Philippe Tribolet, Sofradir’s research and development vice president.
The mid-wave band is used to acquire the target, and the short-wave band distinguishes the decoy flares from the jet engine, Tribolet said.
A trend in dual-band technology has grown in response to demand for more complex features in large-format IR detectors.
These features improve target identification, signal recognition and clutter rejection.
Janus was developed in cooperation with Sofradir’s partner CEA-Leti-Minatec. The detector uses stable, low-defect-density photovoltaic cells built of mercury cadmium telluride (MCT or HgCdTe) to deliver images of 320 by 256 pixels.
The chips are manufactured using molecular beam epitaxy, a technique in which single crystals are deposited on a base in near-vacuum. Sofradir is based in Veurey-Voroize, near the French Alps.
A French Air Force spokesman said the service is working to replace its older infrared sensors. For example, it is replacing the older Clio infrared cameras on its Fennec helicopters with the new, lighter FLIR Ultra 7000 MM.
The new gear is also built to perform better in high humidity, which makes it useful for helicopters that operate in France’s tropical overseas department of French Guiana.
Five camera units were delivered to the Air Force in 2006 and five were planned for this year. Fennec aircraft of the quick reaction unit at the Villacoublay airbase, covering the Ile de France operational zone, will be equipped with the new cameras.
The FSO will provide all-weather air-to-air and air-to-ground surveillance and targeting and, says Thomson-CSF Optronique, is the first such system in the West to work on the 3-5 micron band as well as the usual 8-12 micron wavelength, the former providing “considerably improved detection in humid conditions”. 1999/05/05/.
Next stage to dual bandwidth technology:
A breakthrough in the Infrared Detection technology.
Based on: Unique Multi-color infrared detectors and band substraction algorithms.
http://www.thalesgroup.com/assets/0/93/238/5d9f69f3-fe39-459b-98f1-7e2a6cec4cfb.pdf?LangType=2057
Thanks for the lecture aurcov. 😀
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