LOFAR Opens Up the Low-Frequency Universe

I do not know if was already posted ...

ScienceDaily (Apr. 13, 2010) — The Low Frequency Array (LOFAR), a new pan-European radio astronomy facility, has started mapping the Universe at very low energy wavelengths, a part of the electromagnetic spectrum that is relatively unexplored. It will detect faint signals from the first stars and mini-black holes that emerged when the Universe was only 500 000 years old -- and will also be looking for signs of other civilisations in the Universe closer to home.

Full article: www.sciencedaily.com...

I'm glad they are making progress. The program should have been completed in 2009.

Hopefully we'll be listening to our alien neighbours FM radio broadcasts in a few years. If they are not too far away. If they use radio waves at all. If they don't use numeric compression that makes transmissions sound like noise.

But why do they catch the radio waves with a pyramid antenna?
Is it the same concept as the Pyramid in Egypt?

www.lofar.org...

Originally posted by hawk123
But why do they catch the radio waves with a pyramid antenna?
Is it the same concept as the Pyramid in Egypt?

www.lofar.org...

No, the original concept was for a flat reflector with a dipole above it and the reflector shown was actually round:

citeseerx.ist.psu.edu...
[atsimg]http://files.abovetopsecret.com/images/member/164dca8c2781.png[/atsimg]

Figure 7. Impression of single polarisation LOFAR antenna element

To obtain a directional radiation pattern the dipole is combined with a flat metallic reflector. The centre dipole feed point is
positioned about ¼ of a wavelength above the reflector at the highest operation frequency. As a result, at lower frequencies
this distance, expressed in wavelength, is always less then a ¼. In this way a broad directional beam pattern is obtained
which shows no bifurcation over the operational frequency range. Fig. 7 shows a sketch of the LOFAR antenna element.

I'm assuming they ended up with a square design instead of round for cost reasons as it's easier and cheaper to make squares than to make disc shapes.

This should be interesting to explore what hasn't been previously explored, we might make some interesting discoveries. It looks like the snow poses a major problem for this array though.