The IBT (Itty Bitty radio Telescope)
at Tamke-Allan Observatory
David E. Fields, Observatory Director
Tamke Allan Observatory
Roane State Community College
Harriman, TN 37748
How do we introduce and demonstrate
Radio Astronomy at Tamke-Allan
Observatory?
Abstract
Initial work with the nominal 11.7 Ghz Ku band SARA-NRAO Radio Telescopes has shown them to be excellent little devices for
introducing radio astronomy to students and the public. They are usually referred to as Itty Bitty Telescopes (IBTs), with a nod to their
inspiration, the Green Bank Telescope (GBT). The IBT that we use at Tamke-Allan Observatory (TAO) is the most well-traveled of all of
our radio telescopes, and we consider it to be an excellent introduction to radio astronomy. Other radio telescopes that we use at TAO are a
20.5 MHz system for Jupiter and Solar monitoring; a 6-m dish, and a 1420 MHz system for neutral hydrogen interstellar cloud monitoring.
The IBT was built by Kerry Smith of the Society of Amateur Radio Astronomers (SARA) for the SARA/NRAO Navigator outreach
program. Local SARA/NRAO Navigators include Tyler Moore, John Mannone, and David Fields. See www.radio-astronomy.org
Please visit Tamke-Allan Observatory. We are open each 1st and 3rd Saturday of the month. See www.roanestate.edu/obs
Inspiration for the IBT – The Green Bank radio Telescope
The Green Bank radio Telescope, aka the Great Big radio Telescope (GBT) is the largest steerable radio telescope on the planet. It is
100 meters (300 feet) in diameter and has been used to study many distant astronomical radio sources. On the left is shown the GBT
which, like our 18” diameter IBT, has an off-axis parabolic construction. The IBT is steerable, portable, and a great demonstration tool
to show how to do radio astronomy. The IBT has audio and digital output for recording and sending data via the Internet using our
SkyPipe program. Radio telescopes show us much of the structure of our universe because of their sensitivity and resolution. The
sensitivity comes from the great capture-area of the large radio telescopes, while resolution is a function of both size and the
wavelength, λ. For a group of radio telescopes properly connected, the effective size of the system is not the diameter of one dish;
instead, it is the spacing between the radio telescopes.
Where are we using the TAO Itty Bitty radio Telescope?
Radio sources are wellrepresented in the sky, but
most are comparatively
weak. Our small-aperture
IBT easily sees the sun,
many satellites, and large
room-temperature objects,
including people. Here Ron
Dinkin’s family and Katie
Sloop are enjoying using the
IBT. Our telescope dome in
the background is closed,
since the day was cloudy.
The IBT operates through the
clouds.
Roane State Community College hosts a minority workshop in science each
summer. This year the astronomy lectures featured an introduction to radio
astronomy using our IBT; telescope making; and a discussion about our solar
system.
Tamke Allan Observatory is located in Rockwood Tennessee and is
operated by Roane State Community College.
Astronomy is a gateway to the sciences. Through astronomy, we
recognize the relevance of biology and the necessity of physics and
chemistry for understanding our place in the universe. Unfortunately,
because of illumination from street lamps, car headlights and lighted
signs, the night skies are becoming less accessible. Only when we
find an isolated mountain, such as the one on which the Tamke-Allan
Observatory (TAO) is located, can we rediscover our galaxy—the
Milky Way— and obtain magnified glimpses of distant planets, the
star-like moons of other planets and the diffuse glow of distant
nebulae and comets.
•TAO supports college courses in astronomy.
•Mary Watson Research Scholarships are available for high school
students.
•Public Stargazes are offered twice per month, on the First and
Third Saturday.
•Research in Optical and Radio Astronomy by students and local
astronomers keeps us current in astronomy topics.
•Sidewalk Astronomy activities bring astronomy to schools and
public events.
•Please visit our website http://www.roanestate.edu/obs for more
information.
Both the GBT and the IBT receive signals from celestial radio emitters. Like optical telescopes, they are used to listen to signals that
penetrate transmission ‘windows’ through our atmosphere/ionosphere, as shown by the graph on the left. The cartoon on the right
reminds us of the diversity of radio sources, which include neutral hydrogen and organic molecular clouds, stars, planets, rocks and a
plethora of man-made devices such as satellites and communications equipment..
The TAO IBT has also been used during radio astronomy lectures at the Oak
Ridge Civil Air Patrol squadron on two occasions. Here cadets discuss
whether a streetlight emits enough radio energy to be detected. The IBT was
demonstrated recently at a fly-in at Rockwood Airport.