dsp finals
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ELECTROMAGNETIC SPECTRUM - the range of all possible frequencies of electromagnetic radiation
1. GAMMA RADIATION2. XRAY RADIATION3. UV RADIATION4. VISIBLE RADIATION5. IR RADIATION6. MICROWAVE RADIATION7. RADIO WAVES
1. GAMMA RADIATION2. XRAY RADIATION3. UV RADIATION4. VISIBLE RADIATION5. IR RADIATION6. MICROWAVE RADIATION7. RADIO WAVES
electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres (µm), and extending conventionally to 300 µm.
Infrared light is used in industrial, scientific, and medical applications.
Night-vision devices using infrared illumination allow people or animals to be observed without the observer being detected. In astronomy, imaging at infrared wavelengths allows observation of objects obscured by interstellar dust. Infrared imaging cameras are used to detect heat loss in insulated systems, observe changing blood flow in the skin, and overheating of electrical apparatus.
gaining importance in the applied spectroscopy particularly in the fields of NIR, SWIR, MWIR, and LWIR spectral regions
Typical applications include biological, mineralogical, defense, and industrial measurements.
collects and processes information from across the electromagnetic spectrum
Much as the human eye sees visible light in three bands (red, green, and blue), spectral imaging divides the spectrum into many more bands.
This technique of dividing images into bands can be extended beyond the visible.
Engineers build sensors and processing systems to provide such capability for application in agriculture, mineralogy, physics, and surveillance.
Hyperspectral sensors look at objects using a vast portion of the electromagnetic spectrum.
Hyperspectral (AVIRIS) image of Mammoth Mountans, California. 1024 x 512 pixles, 224 bands, approximately 300 Mbytes od data.
Hyperspectral surveillance is the implementation of hyperspectral scanning technology for surveillance purposes.
Hyperspectral imaging is particularly useful in military surveillance because of countermeasures that military entities now take to avoid airborne surveillance.
The idea that drives hyperspectralsurveillance is that hyperspectralscanning draws information from such a large portion of the light spectrum that any given object should have a unique spectral signature in at least a few of the many bands that are scanned.
The soldiers from DEVGRU who killed Osama bin Laden in May 2011 used this(hyperspectral surveillance) technology while conducting the raid (Operation Neptune's Spear) on Osama bin Laden's compound in Abbottabad, Pakistan.
Hyperspectral thermal infrared emission measurement, an outdoor scan in winter conditions, ambient temperature -15°C - relative radiance spectra from various targets in the image are shown with arrows.
In infrared photography, infrared filters are used to capture the near-infrared spectrum.
Digital cameras often use infrared blockers.
Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers.
Naturally occurring radio waves are made by lightning, or by astronomical objects.
Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications.
subfield of astronomy that studies celestial objects at radio frequencies
Subsequent observations have identified a number of different sources of radio emission.
Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis.
To “image” a region of the sky in more detail, multiple overlapping scans can be recorded and pieced together in a mosaic image.
An optical image of the galaxy M87 (HST), a radio image of same galaxy using Interferometry
Very Long Baseline Interferometry (VLBI)
It allows observations of an object that are made simultaneously by many telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.
Very Long Baseline Interferometry (VLBI)
VLBI is most well known for imaging distant cosmic radio sources, spacecraft tracking, and for applications in astrometry.
The Parkes64-m (210-ft) radio telescope in Australia produced this radio map of the Large MagellanicCloud.
refers to any study or application of sound waves higher in frequency than the human audible range
They are used in many applications including plastic welding, medicine, jewelry cleaning, and nondestructive test.
the visualization of living animals for research purposes, such as drug development
These imaging systems can be categorized into primarily morphological/anatomical and primarily molecular imaging techniques.
High-frequency micro-ultrasound, magnetic resonance imaging (MRI) and computed tomography (CT) are usually used for anatomical imaging, while optical imaging (fluorescence and bioluminescence), positron emission tomography (PET), and single photon emission computed tomography (SPECT) are usually used for molecular visualizations.
High-frequency micro-ultrasound works through the generation of harmless sound waves from transducers into living systems. As the sound waves propagate through tissue, they are reflected back and picked up by the transducer, and can then be translated into 2D and 3D images.
Micro-ultrasound is specifically developed for small animal research by VisualSonics, with frequencies ranging from 15 MHz to 80 MHz,[3] compared with clinical ultrasound systems which range from 3-15 MHz
VEVO 2100 BY VisualSonic Tech.
Vevo 2100 is a portable imaging modality which means the system can be easilytransported from one site to the next and allows for multiple users to perform andstore multiple examinations/ studies. The addition of more animals to each study ispossible as well as re-assessment of study data a later dates for the purpose ofanalysis of that data.
Micro-ultrasound is the only real-time imaging modality per se, capturing data at up to 1000 frames per second.
Micro-ultrasound systems are portable, do not require any dedicated facilities, and is extremely cost-effective compared to other systems.
Currently, imaging of up to 30 µm is possible, allowing the visualization of tiny vasculature in cancer angiogenesis.
Micro-ultrasound devices have unique properties pertaining to an ultrasound research interface, where users of these devices get access to raw data typically unavailable on most commercial ultrasound (micro and non-micro) systems.
Typically, micro-ultrasound can image tissue of around 3 cm below the skin, and this is more than sufficient for small animals such as mice.
The performance of ultrasound imaging is often perceived as to be linked with the experience and skills of the operator.
The advances in micro-ultrasound has been able to aid cancer research in a plethora of ways. For example, researchers can easily quantify tumor size in two and three dimensions.
Because of its real-time nature, micro-ultrasound can also guide micro-injections of drugs, stem cells, etc. into small animals without the need for surgical intervention.
Acoustics is the interdisciplinary science that deals with the
study of all mechanical waves in gases, liquids, and solids
including vibration, sound, ultrasound andinfrasound. A scientist
who works in the field of acoustics is an acoustician while
someone working in the field of acoustics technology may be called
an acoustical engineer
Five basic steps :
The study of acoustics revolves around the generation, propagation
and reception of mechanical waves and vibrations.
The steps shown in the above diagram can be found in any acoustical
event or process.
Acoustic Micro Imaging
a method of evaluating materials and bonding for various
micro electronic applications. Acoustic micro imaging uses
high frequency ultrasound (5 to 300 MHz) to image the
internal features of samples
Acoustic Micro Imaging can be
optimized for analytical studies
where layer-by-layer analysis is needed.
broadband pulse viewed in the time domain
The five basic steps are found equally well whether we are talking about an earthquake, a submarine using sonar to locate its foe, or a band playing in a rock concert.
The higher the frequency the shorter the
wavelength and the higher the resolution
potential.
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Analytic instruments such as
the Spectrum analyzer facilitate
visualization and measurement
of acoustic signals and their
properties.
The Spectrogram produced by
such an instrument is a graphical
display of the time varying
pressure level and frequency
profiles which give a specific
acoustic signal its defining
character.
Spectrogram of a young girl saying "oh, no"
AudioPaint generates
sounds from pictures.
The program can read
JPEG, GIF and BMP files
and translates each pixel
position and color into
frequency, amplitude and
pan information. It's a
kind of massive additive
synthesis tool.
AudioPaint
Hyperupic [Image to Sound Tool
Hyperupic is a tool for creating sounds from digital images. Hyperupic is intended to be a musical tool for composers, but it is sufficiently general for many sonificationapplications as well. Hyperupic is available for MacOS X.
Virtual Reality
In Virtual Reality (VR) systems -all human sensory systems
have to be stimulated in a natural way to enhance immersion
into computer-generated environments with which users can
interact freely and naturally
One of the major contributions of this comprehensive system is
the realization as a software-only solution that makes it possible
to use this technology on a standard PC basis. It frees the user
of any costly DSP technology or other custom hardware which
additionally is hard to maintain. In addition to that it is to our
knowledge the first approach to install a versatile and stable
real-time binaural acoustics system with dynamic CTC in a
CAVE-like environment.
shows a measurement of the
artificial head of the Institute of
Technical Acoustics (ITA) of
RWTH Aachen University under
120 degree relating to the frontal
direction in the horizontal plane.
The Interaural Time Difference
(ITD) can be assessed in the
time domain plot. The Interaural
Level Difference (ILD) is shown
in the frequency domain plot and
clarifies the frequency
dependent level increase at the
ear turned toward the sound
source and the decrease at the
ear that is turned away from the
sound source.
Methods for Acoustical ImagingThe basic theory of the wave field
synthesis is the Huygens′ principle.
An array of loudspeakers (ranging
from just a few to some hundreds in
number) is placed in the same
position as a microphone array was
placed at the time of recording the
sound event in order to reproduce
an entire real sound field. In a VR
environment the loudspeaker signal
will then be calculated for a given
position of one or more virtual
sources.
Five sided projection CAVE-like virtual environment using optical
tracking. Possible loudspeakers are colored in green and
mounted on the rack on top of the device
1234-8 ) 5 basic steps(acoustic)
Sources for images
9) refers to any study or application of sound waves higher in frequency than the human audible range
10)TRUE/FALSE: In astronomy, imaging at infrared wavelengths allows examination of objects obscured by interstellar dust.