Telescopes

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9

Slide 93

Equatorial mount

Antenna

Receiver

Polar axis

Polaris

Declination track

Right ascension track

Green Bank 140 ft

Slide 94

Radio, millimeter, and submillimeter astronomy

The place of radio, millimeter, and submillimeter astronomy the study of astronomy

The parts of a radio telescope and how it works

The two big challenges of radio astronomy overcome by radio astronomers

Tiny signal strength of radio signals

Low angular resolution

Next generation radio, millimeter, and submillimeter telescopes

Slide 95

Cosmic radio signals are very weak!

All the energy collected by all the radio telescopes on Earth during the >60 year history of radio astronomy amounts to no more than the energy released when a few raindrops hit the ground!

Slide 96

Cosmic radio signals are very weak!

This places strict requirements on the design of a radio telescope!

Slide 97

Design to overcome small signal strength

Antenna

LARGE COLLECTING AREA

Receiver

LOW NOISE

Slide 98

Design to overcome small signal strength

Antenna

LARGE COLLECTING AREA

Receiver

LOW NOISE

Slide 99

Large collecting area

Parkes 64-meter radio telescope

Slide 100

Larger collecting area

100-meter GBT Green Bank Telescope (Great Big Telescope)

Slide 101

Largest collecting area

300 meter radio telescope, Arecibo Observatory

Slide 102

Largest dish (but not fully steerable)

300 meter radio telescope at Arecibo Observatory

Slide 103

Arecibo radio telescope

Since Arecibo’s dish is not moveable, tracking is accomplished by moving the receivers instead.

Receivers are inside

the dome

Receiver

Slide 104

Arecibo radio telescope

Altitude track

Azimuth track

Slide 105

Requirements of a radio telescope