iPhone 12 Pro Max
Ć’/1.6
5.1 mm
1/120
64

Having just found a home in our space museum, this pyramidal tree is the focal point “feed” from the Allen Telescope Array that SETI is using to search for signs of extraterrestrial intelligence in distant solar systems.

Nestled up in the focal point of each dish, the tree of triangles tunes across a wide frequency band, from 0.5 to 11 GHz. Near the tip, highly specialized low-noise amplifiers (LNAs) take the signal from the feed and output it onto micro-coax cables to the back of the feed where the control electronics reside. The analog signal is then transmitted via fiber-optic links to the signal processing room where it is converted to a digital signal for correlating, beam forming and signal processing, integrating across the array of antennae.

The net effect is a phased array antenna that acts like an integrated dish observing three different solar systems at the same time. This allows them to ignore interference and common spectra by focusing the search on signal that comes from only one of the three systems under observation. Here is a
simple pictorial of how the phased-array antennae work…

An artifact in the Future Ventures’ 🚀 Space Collection. Thanks S.E.T.I.

One response to “E.T. Phone Home 📡”

  1. jurvetson Avatar
    jurvetson

    Placement in the new wingThe new wing of the Future Venture's Space Museumjust the tip… with delicate tubes inside:Under the tree of triangles is a pyramid of optoelectronics…. the ATA PYRAMID LOG PERIODIC FEED:The Allen Telescope Array "This is not an incremental step forward: the Allen Telescope Array was constructed to increase the stellar reconnaissance for artificial signals by orders of magnitude. It is a very large step for SETI research.

    The design for the Allen Telescope Array’s antennas – so clearly different from the type of “tripod” arrangement found in many backyard satellite dishes – incorporates so-called offset optics because sometimes, as in football, going to the side can reduce interference. The antennas use what’s known as an offset Gregorian system. A secondary mirror bounces incoming radio signals collected by the large (6.1 meter diameter) primary reflector back to the feed antenna (hidden from view by a fabric shroud) where they are amplified and sent on to the control buildings on an optical fiber.

    By introducing a secondary mirror and a surrounding shroud, the antenna is less likely to pick up noisy radio radiation from the (relatively hot) ground surrounding the telescope. Moving the reflector assembly off-center minimizes the chance of terrestrial signals bouncing off the antenna structures and interfering with our search for intentional transmissions."

    The search ends at home with a binary systemsporting their Drake Equation shirts from SETI by cosmic coincidence.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *