Amateur Radio Astronomy

(or “Another Way You Can Spend a Lot More Money in This Hobby”)

ByDon Pullen

Presented toCherry Springs Star Party – June 2012

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www.amateurastronomy.org

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What is Radio Astronomy?

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What is Radio Astronomy?

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What is Radio?

Photons

Radio

6Electromagnetic Spectrum (EM)

Science - Math

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c = ƒ * λ or λ = c / ƒ or ƒ = c / λ

E = h * ƒ

Where:c = Speed of Light (~300,000,000 m/sec)λ = wavelengthƒ = frequencyE = energyh = Planck’s constant (6.626 x 10-34 Joules.sec)

Main points…

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• Radio, Light and more are all part of Electromagnetic spectrum separated by different frequencies and wavelengths.

• Frequency and wavelength are related.

• As frequency increases, wavelength decreases (and vice-versa).• This means higher frequencies require smaller antennas.

• Higher frequencies means higher energy levels which results in different properties.

Radio Spectrum

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Atmosphere

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Atmosphere

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Main points…

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• Only certain portions of the EM spectrum can reach the surface of the Earth since other portions are either reflected, refracted or absorbed by the Magnetosphere, the Ionosphere or the atmosphere.

• We know that the Ozone layer blocks most of the UV. Other components of the atmosphere also block other portions of the EM spectrum.

• To observe in other parts of the EM, we need satellites in space.

• Light reaches the Earth, as does most of the Radio EM and some Microwave and Infrared. This is why we use Radio and why it’s suitable for amateur work.

What can be seen?

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What can be seen?

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Radio Sources

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•Sun•Jupiter•Saturn & Venus (weak and intermittent)•Center of Milky Way•Pulsars•Man-made sources

Amateur Radio Astronomy +

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Amateur Radio Astronomy +

Radio Frequencies Used

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Solar and Jupiter• 13.36 - 13.41 MHz• 25.55 - 25.67 MHz

Pulsars• 73.00 - 74.60 MHz • 150.05 - 153.00 MHz • 406.10 - 410.00 MHz

Hydrogen Line Emission• 1400.0 - 1427.0 MHz

Reserved Radio Frequencies

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How to Get Started

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CHEAT!

Use the Internet

Amateur Radio AstronomyOrganizations

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• SARA – Society for Amateur Radio Astronomerswww.radio-astronomy.org

• NRAO – National Radio Astronomy Observatorywww.nrao.edu

• AAVSO – American Association of Variable Star Observerswww.aavso.org

• UKARANET – UK Amateur Radio Astronomers Networkwww.ukaranet.org.uk

Simplest - Meteor Detection

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Meteor Detection• Can use FM radio tuned to distant station– Best over 200 mi away– Use radio-locator.com for list of stations– Also wikipedia for stations by state

• FM normally is line-of-sight since escapes to space• Ionization caused by meteor is reflective to various radio

frequencies including FM.• Independent of day/night cycle or solar activity.– But better after midnight when moving into meteors

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Meteor Detection

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Meteor Detection

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Meteor Detection - Advanced

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Solar Monitoring

• Cheat – use internet sites like SpaceWeather.com, or NOAA.

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Other Solar Monitoring sites:

•SOHO – sohowww.nascom.nasa.gov•SDO – sdo.gsfc.nasa.gov•NSO – www.nso.edu•Stanford – sun.stanford.edu

Solar - Indirect

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Solar wind and energetic particles (X-Rays) constantly bombard Earth’s Magnetosphere and

Ionosphere causing them to deflect or ionize.

Solar - Indirect

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Changes in Ionosphere and Magnetosphere can be detected with 2 fairly simple techniques.

•Radio propagation

•Magnetometer

Solar - Indirect

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Radio Propagation

How radio signals “bounce” off the ionosphere

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Solar - Indirect

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Radio Propagation

Solar - Indirect

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Radio Propagation

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Solar - Indirect

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Radio Propagation

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Solar - Indirect

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Radio Propagation

Solar - Indirect

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SID – Sudden Ionospheric Disturbance

Monitors a standard known radio signal and notes changes in signal strength directly

indicating variations in ionosphere and indirectly indicating changes in solar X-Ray emission.

Citizen Science!

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Solar - Indirect

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SID – Sudden Ionospheric Disturbance

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SID – Receivers – Kits/Preassembled

Solar - Indirect

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Solar - IndirectSID – Antennas

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Solar - IndirectSID – Antennas

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Solar - IndirectSID – More Advanced

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Solar - IndirectMagnetometer

Monitors deflections in Earth’s magnetosphere by amplifying changes in compass bearings.

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Solar - IndirectMagnetometer

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Radio JOVE - radiojove.gsfc.nasa.govReceiver

Solar - Direct

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Radio JOVE - Antenna

Solar - Direct

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Solar Bursts received near the frequency 20 MHz often turn on rapidly and decay slowly -- looking somewhat like a shark fin on the strip chart record. These bursts

can be quite strong and often last for tens of seconds. You will hear the weak galactic background noise for several seconds, followed by a Solar radio noise burst.

Radio JOVE - SOLAR BURSTSSolar - Direct

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Jupiter L-Bursts sound like ocean waves breaking up on a beach. Much of the L-burst structure is formed as signals travel though the interplanetary

medium from Jupiter to the Earth.

Radio JOVE - JUPITER L-BURSTS

Jupiter

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Jupiter S-Bursts sound like a handful to pebbles thrown on a tin roof (or popcorn being cooked). These bursts each last for a few thousandths of a

second and occur at rates as high as several dozen per second.

Radio JOVE - JUPITER S-BURSTS

Jupiter

Radio Jove - Advanced

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InterferometryIt’s possible to improve signal and reduce interference using a

method called Interferometry.

2 or more stations/antenna systems are set up and data fed to computer to calculate similarities and differences.

Advanced

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Advanced

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IBT – Itty Bitty Telescope

Advanced

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Advanced

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Professional Radio Telescopes

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• NRAO – National Radio Astronomy Observatorywww.nrao.edu (links to Greenbank, VLBA, ALMA & EVLA)

• Square Kilometer Array:www.skatelescope.org

• LOFAR – Low Frequency Arraywww.lofar.org

• Arecibo – www.naic.edu

• Deep Space Networkdeepspace.jpl.nasa.gov/dsn

Books

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Radiosky publishing has a lot of books• Radio Astronomy Projects by William Lonc ~$27• Radio Astronomy teachers Workbook ~$20• Radio Astronomy by John Kraus ~$50

Some others• Radio Science Observing by Joe Carr – Prompt Publishing ~$70• An Introduction to Radio Astronomy by Bernard F Burke and Francis Graham-Smith – Cambridge University Press ~$80 (not a beginners book)• The Radio Sky and How to Observe It by Jeff Lashley – Springer Publishing ~$30• Amateur Radio Astronomy by John Fielding – Radio Society of Great Britain ~$35

Miscellanea

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List of Amateur Radio Astronomy websites:- www.bambi.net/sara/sites_list.html

Good resource website:- radiosky.com

Reserved Radio Frequencies for Astronomy- www.setileague.org/articles/protectd.htm- www.ukaranet.org.uk/basics/frequency_allocation.htm

Pop Bottle Magnetometer- image.gsfc.nasa.gov/poetry/workbook/page9.html

References

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• www.radio-astronomy.org/pdf/sara-beginner-booklet.pdf

• www.nrao.edu/index.php/learn/radioastronomy

• www.cv.nrao.edu/course/astr534/ERA.shtml

• 1987 & 1999 ARRL Handbooks

• sid.stanford.edu

• en.wikipedia.org/wiki/Radio_astronomy

• www.aavso.org

• www.ukaranet.org.uk

Suppliers

• www.radioastronomysupplies.com• www.alfaradio.ca• www.thesatelliteshop.net

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Thank You

Presentation will be available online in about 1 week at:

www.amateurastronomy.orgunder LINKS button