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Radio astronomy projects, by Jeffrey Lichtman, SARA

The radio spectrum is by far less used than its visible counterpart. It is a challenge for an amateur to get information from this so-called "noise from space" and be interested in such activities. The next list gathers potential subjects which confirm however there are a lot of thing to do even using small infrastructures. 

Some of them are ambitious but well in the range of the capabilities of an amateur radio telescope.

In parallel to these activities if you can do visual observation of the same areas, you can try to correlate these observations with radio records. Then you will begin to understand where is the true utility of your work.

The solar activity

Being the most  powerful radiosource, the Sun is of course our best observation subject. Your equipment only requests a broad beamed radio telescope, optionaly fixed on an equatorial mount. In a period of a few months you can detect the periodicity of the signals induced by its rotational rate. With some accuracy you can also detect the non-uniformity of this rate according to the solar latitude. 

Le Soleil radioélectrique

Jupiter storms

These electrical storms we can heard in the HF bands between 18-24 MHz are of very high intensity and may be detected with communications type receivers tuned to an inactive portion of this band. Antennas used are identical with any antenna system resonant at this frequency. The noises are so powerful that the antenna need not necessarily be resonant.

Note that from time to time, when severe storms are expected on Jupiter, NASA provides a link to its receivers through the Internet.

Jupiter radioélectrique

The shape of the Milky Way

Second by its power, the Milky Way is also a subject of great interest. Its shape is easily discernable by a simple radio telescope. The easiest method to detect it is using a drift scan. While the sky rotates, the angular distance to the galactic center will vary and the signal strenght will be modulated according to the angular separation from the galactic core.

With an more accuracy system the inclination of the galactic equator to the ecliptic can also be detected.

Thermal emissions

Remember Jansky's pioneer work. With a radio telescope relatively sensitive you can operate in the Very High Frequency bands of microwaves to detect the temperture of the subject. The electromagnetic energy of the blackbody is everywhere present and can easily be recorded. This more demonstrative use of the radio telescope can be tested on various subjects, from a human body to the nigh sky or in presence of a warm object.  Then you can compare your output signal with the true temperature of the subject analyzed.

With application of appropriate formulas and knowing the characteristics of the antenna pattern you can also estimate the temperature of the Sun and the Moon.

Interstellar Hydrogen clouds

Hydrogen clouds emission can be detected using a quite sensitive antennna and an oscilloscope display (completed with a ramp voltage generator and a downconverter stage). As the sources can be very short is sizes, the bandwidth of your receiver must be narrow enough to resolve hydrogen lines but not too much to preserve the sensibility. The frequency must also be steady to be able to pratice some calibration and in the bast cases to observe the doppler shoft of the lines.

This very interesting activity give you the chance to map the relative motions of bright hydrogen clouds distributed all over the sky.

High energy pulses

High energy pulses or HEP have been reported for years by amateurs with some spots in the center part of our Milky May. Recent gamma rays observations have revealed some of these HEP have indeed been correlated with observations did by amateurs. But not all are accociated with galactical sources. Therefore a confirmation of their origin is required as well as the coorelation between their radio signal and a potential gamma burst. This work requests the cooperation of many amateurs, widely separated, sharing their observations and correlating them with the simultaneous observations from professionals.

Of course such project request a high accurate timing calibration but works fine with a standard amateur beam able to track the celestial sphere drift along the night.

You will find more information in the litterature dealing with amateur radio astronomy as listed in the previous pages or in my URLs.

For more information

How does a Radio Telescope Work?, CSIRO

Radioastronomy supplies (formerly Nitehawk)

Weak signal communication resource, Nitehawk

Primaluce Lab (radiotelescopes and accessories)

SARA (Society of Amateur Radio Astronomers)

Build a Homebrew Radio Telescope (PDF), WA8SME, QST, June 2009

Amateur SETI : Project BAMBI

Planetary Radio Group at UFRO

Radio Jove (NASA/GSFC)

Radio-Sky Publishing

SETI League

Signal One

Small Radio Telescope (SRT).

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