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Arrays are used in various applications

Although this example was admittedly somewhat contrived, it is not far fetched. Arrays similar to those that I have been discussing are widely used inthe technology area of spatial signal processing.

Radio astronomy

Perhaps the application that is most familiar to the general public (due to widespread publicity and a very popular movie) is the Paul Allen radio telescope used in the Search for Extraterrestrial Intelligence (SETI) .

In the past, much of this work has been done using a very large dish antenna known as the Arecibo Radio Telescope in Puerto Rico. Efforts are now underway involving an alternative approach that uses a large array of small dishes instead of one large dish.

By properly processing and then summing the outputs produced by the dishes in the array, the users will be able to steer the telescope and possibly to alsoeliminate strong sources of interference.

Seismology

Arrays of seismometers are used by U.S. government agencies to monitor for seismic signals produced by earthquakes in locations nearly halfway around theearth.

By applying complex, frequency dependent weighting factors to the seismometer outputs before summing them, the arrays can be tuned to provide a complexresponse in wavenumber space. For example, the arrays can be processed to form response beams looking in different directions with a beam width that isrelatively constant across a wide band of interesting frequencies. In addition, null points in the wavenumber response can be created to suppress seismic noisethat originates from specific points on the earth such as mines, rock quarries, and cities.

The design and analysis of such array systems use 2D (and sometimes 3D) Fourier transforms. Because the weights that are applied are produced by complexfrequency filters, the transform programs that are used must treat both the space domain data and the wavenumber data as complex (instead of being purely real as in the examples in this module) .

Sonar

Probably ninety percent of all sonar systems currently installed on surface ships and submarines use arrays for steering and processing both active andpassive sonar. In almost all cases, these are 3D arrays. Some of the arrays contain multiple sensors on the surface of a portion of a sphere. Some containmultiple sensors located along slats that are mounted on a frame much like the staves on a barrel. Some are located on the sides of the vessel. There areprobably numerous other geometries in use as well.

A Fourier transform program used with these arrays would normally have to be a 3D Fourier transform program capable of transforming from complex spacefunctions to complex wavenumber functions.

Radar

One of the reasons that sonar is typically processed using arrays has to dowith the wavelength of the signals and the operating environment. It is usually not practical to physically move a sonar sensor large enough to do the job inorder to cause it to look in different directions. Thus arrays of small sensors are used with the ability to steer beams electronically in order to look indifferent directions.

Questions & Answers

What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
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it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
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what is biological synthesis of nanoparticles
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Source:  OpenStax, Digital signal processing - dsp. OpenStax CNX. Jan 06, 2016 Download for free at https://legacy.cnx.org/content/col11642/1.38
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