1. SHRI RAM MURTI SMARAK WOMENS COLLEGE OF ENGINEERING AND TECHNOLOGY

3.  Introduction  Electromagnetic Spectrum  Source of Radio Emission  How radio waves produced?  Electromagnetic Radiation is emitted by Two methods  How Radio Communication Works  Principle of Operation  Components  Characteristics of telescopes  Types of telescopes  Advantages and Disadvantages  Technical Innovation from radio Astronomy  Emerging Technologies  Conclusion

4.  Radio Astronomy is the subfield of Astronomy that studies celestial objects at radio frequencies.  It require large telescopes to observe longer wavelength.

5.  Electromagnetic spectrum is the complete range of electromagnetic wave on continuous distribution from very low range of frequency or very large wavelength to large range of frequency or small wavelength which occupy definite place in spectrum.

6.  These are also known as Astronomical sources.  Solar System-Sun, planets  Stars - star forming regions, old stars, supernova remnants  Galaxies  Milky way-star  Pulsars  Extragalactic -Quasars

7.  Electromagnetic radiation is emitted by charged particles such as electrons when they change speed or direction (or accelerate)  For all types of EM radiation, the simple relationships between wavelength, frequency, and energy are

8.  Thermal emission  Non-thermal emission

9.  It depend on temperature of emitting objects or objects with temperature above absolute zero emits thermal radiation.  It causes atom to move and bump one other- change the direction-emits radiations.  It is of three types..

10.  Blackbody:-absorb all radiation and reflects nothing.  At equilibrium temperature it re-radiates energy- Blackbody radiation.

11.  It o ccurs when gas is ionized.  when gas is ionized charged particles moves around ionized gas.  Electrons accelerated by charged particles and gas emits radiation..

12.  It Involve transition of electron from higher energy level to lower energy level  Protons emits energy equal to energy difference between two levels.

13.  This is not produced by heat, or being radiation having a spectrum that is not the spectrum of a blackbody  It is of two types..

14.  Does not have characteristic signature curve of blackbody radiation.  Due to the acceleration of charged particles with in the magnetic field or The electromagnetic radiation emitted when charged particles are accelerated radially. Synchrotron radiation from a bending magnet

15.  Emitted from pulsars (results from death of massive stars).  It posses magnetic field with accelerate electrons-emit radiations similar to cyclotron radiation  It appear as flash of light.

16.  Sound and radio waves are different phenomena  1-A sound wave is produced with a frequency of 5 Hz - 20 kHz  A microphone converts the sound wave into an electrical signal.  The electrical wave is used to encode or modulate a high- frequency "carrier" radio wave. The carrier wave itself does not include any of the sound information until it has been modulated.

17.  The carrier wave can either be amplitude modulated (AM, top) by the electrical signal, or frequency modulated (FM, bottom).  The signal is transmitted by a radio broadcast tower.  our radio contains an antenna to detect the transmitted signal, a tuner to pick out the desired frequency.  The speakers convert the electrical signal into physical vibrations

18.  The radiations on the parabolic surface is reflected to focus. It induces an electric current to receiver. Signal is amplified to get the image.

19.  Large radio antenna  Sensitive radio receiver

20.  It should have large collecting area. Resolution should be good  Diameter should be many times greater than wave length of radiation.

21.  The Very Large Array (VLA)  The Australia Telescope Compact Array (ATCA)  The Giant Metrewave Radio Telescope (GMRT)  Arecibo

22.  Radio astronomy telescope located on plaus of San Augaustine,New Mexico,USA.It consists 27 antenna arranged in 3 arm.

23.  Radio telescope located at Paul Wild Observatory in Australia.  It consists 6 dishes.  5 can be moved along 3km railway track.

24.  This is located in pune in India is the world’s largest array.  In this array,30 dishes of 45 in diameter separated by 25 km.

25.  World’s biggest single dish telescope located in city of Arecibo in Pulrto Reco.  It is the largest single (305m) aperture telescope ever constructed.

26.  Not affected by the weather.  Radio telescope observe day and night.  To get good quality of images with all details is more complicated.  To produce images complicated procedure is required

27.  Radio location of cell phone calls  Transistors and Cryogenic coolers  Medical and scientific imaging

28.  The purpose of the National Radio Astronomy Observatory is to do fundamental research on the nature of the universe in which we live. This research seeks to answer some of the biggest questions we can ask, such as how did the universe begin (or did it begin), how big is it, how old is it, and how will it end (or will it end)? As the science that provides the framework knowledge of where we, and the planet on which we live, fit into the environment of the universe.

29.  Communications Disruptive Warning and Prevention of Damage from Solar Flares.  Grid Computing Applications.  Laser Metrology and Precision Rangefinders