A new development that will be presented at the "Remote Sensing" conference that will be held at the Ariel University Center in Samaria on June 1
A new radar system that operates in the terahertz range of frequencies to detect weapons and camouflaged explosives, this is one of the new developments that will be presented at the "Sensing, Imaging and Remote Detection Technologies" conference that will be held at the initiative of the Ariel University Center in Samaria on Tuesday, June 1, 2010. Use of terahertz frequencies - Hertz is a relatively new field in science. The remote sensing system is based on the FMCW radar and was developed by scientists from the Homeland Security Research Center at the University Center, which operates in collaboration with ALTA and Rafael, with the support of the Ministry of Defense.
With the increase in terrorist activities in the world carried out by suicide terrorists, and the use of powerful explosives and dangerous biological and chemical substances intended to harm population concentrations, the need arose for the combination of sophisticated methods and means to detect the threats before they reach the point of realization. One of the challenges that arise in dealing with the form of terrorism of recent years, is the need for remote detection of the threat and its neutralization ahead of a potential time. The system operates in unique frequency ranges that allow detection with high resolution, this is in contrast to the systems that exist in the world that work in the microwave frequency range, and therefore do not allow detection with good resolution.
In recent years, interest has grown in the possibility of utilizing electromagnetic radiation in the millimeter wave (mm) and terahertz spectrum for remote sensing of suspicious objects. This range extends from 300GHz to 10THz (wavelengths of 1mm-300µm), is located above the EHF (Extremely High Frequencies) range and touches the infrared range. The fact that the radiation spectrum is located between the microwave frequencies and the optical domain is of particular importance, since the radiation in the terahertz range combines features from both domains. On the one hand, the short wavelengths enable high-resolution detection, imaging and high-resolution image display. On the other hand, similar to microwaves, the radiation penetrates dielectric materials that are not transparent to radiation in the optical and near-infrared range. This fact allows for the development of means for remote detection and imaging of suspicious objects hidden under clothing, and in the low areas of the spectrum, even beyond walls.
When discussing approaches to implementing remote sensing systems, two modes of operation are distinguished - passive and active. The passive detection is based on the detection of objects from the thermal background radiation emitted or scattered from them. This is low intensity radiation, a fact that limits the detection range to a few meters.
The detection system based on the FMCW radar operates at a frequency of 330 GHz and is an active system, which includes a transmitter with a power of about 10 mW and a receiver with high sensitivity.
The radar is based on transmitting a signal whose instantaneous frequency changes linearly in time cycles. As an example, you can see the significant improvement in the resolution obtained in the CD-ROM image. In the next phase of the research, an additional reception channel will be added to receive an image from two points of view, which will prevent distortions resulting from secular reflections and build an improved image by integrating the information received in both receivers.
The Homeland Security Research Center at the University Center is headed by Prof. Yosef Panahsi, and he carried out the development work together with Prof. Boris Kapilevich and Danny Hardon. At the "Sensing, Imaging and Remote Detection Technologies" conference, approximately 30 studies will be presented on the topics of electromagnetic and optical radiation, detection and imaging and in the security-industrial field, environmental monitoring, as well as research in the field of health and medicine.
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I carefully read your interesting discussion and I would like to note the following:
1. The domain of Extremely High Frequencies or EHF for short extends in the frequency range of 30-300GHz (a wavelength of 1cm which goes down to 1mm). The range is located above the range of microwave frequencies known as SHF. The field is also called millimeter waves.
2. The system in question operates a little above the EHF range, in a frequency range that has received the name "terahertz" in recent years. These are "sub-millimetre" waves.
3. The "terahertz" field does not yet have a precise definition. It is customary to refer to the frequency range between 300GHz and 3THz (wavelength of 100 microns). Some even extend it up to 10THz, a field included in what is called "far infrared" (FIR).
4. The innovation in this system, which is a radar system operating in the frequency range, which in the absence of coherent radiation sources, could not be utilized effectively and even received the name Tera-Hertz gap.
5. Being an active system, it enables the discovery and imaging of hidden objects at a distance of several tens of meters, something that cannot be done with passive systems.
More details can be found in the articles we have published in scientific journals or simply come to visit...
Prof. Yossi Panhassi
The meaning of "remote sensing" refers to relative distance.
When you want to check that a person is not carrying salt on his way to the plane - it is enough that you don't have to touch him or strip him - even a meter is far enough.
All electromagnetic radiation basically has an infinite range in a vacuum. The limitations on the range are a result of the medium through which the radiation must pass.
It is true that terahertz radiation is absorbed by the atmosphere too quickly when it comes to long-range radio communication, but for the purpose of remote sensing of the type in question here, it is sufficient.
Machel
What does "...for the purposes of remote sensing of suspicious objects" mean?
Terahertz waves are short-range waves, aren't they? Not really understand.
Nimrod:
No one claimed to have invented it.
on the contrary. It is written in the article "In recent years, interest has increased in the possibility of utilizing electromagnetic radiation in the millimeter wave (mm) and terahertz spectrum for the purposes of remote sensing of suspicious objects. "
http://en.wikipedia.org/wiki/Terahertz_radiation
To be precise - the described system is not in the terahertz range because it is at a frequency of 330GHZ (Gigahertz) which is roughly the border between radio and infrared frequencies.
and to the settings
30 to 300 GHz is the EHF range which is the highest range of radio.
300 gigahertz to 400 terahertz is infrared.
Visible light begins at 400 terahertz (red) and ends towards 800 terahertz (violet) and after that, of course, the ultraviolet radiation.
The applications in the article are defined, as it says there, for the 300 GHz to 10 terahertz range, which is the low low range of the infrared. The system in question is at the very bottom of this field and as mentioned is actually at the upper limit of the radio.
I hope I didn't bore you, but the system is not in the terahertz range. It says in the title that the Terra frequencies are still unused - well they are not used as radio because it is not radio but infrared and visible light.
Did not invent the wheel.
See Link
In any case, thank you for developing the system.