Updates from the Parkes Radio Telescope on Australian SETI effort!
We are now able to bring you a snapshot of data being received by the Southern SERENDIP project run by the SETI Australia Centre at UWS using the CSIRO's Parkes radio telescope. The snapshot below is from a file gathered on 2 March, 2000 (note that sometimes there are gaps in updating due to the Multibeam Project, which Southern SERENDIP piggy-backs on, not observing).
Southern SERENDIP takes the same data being received by the Multibeam Project (an all-sky survey and pulsar survey) but examines it in higher resolution in the quest to find a very distinctive 'carrier signal' typical of carrying artifically created information via radio waves.
The Multibeam Project uses a special receiver that allows the sky to be observed through thirteen closely packed 'radio eyes'. Southern SERENDIP's boards are split into two of these radio eyes (compare the top seven with the bottom seven boards on the image below) as a way of coping with Radio Frequency Interference from our own civilisation. If ET were to call, the signal would be in only one eye and be diagonal rather than straight because planets rotate so it would appear to 'postbox' through the frequencies.
How to interpet what you are seeing in the image below: The vertical axis is made up pancake layer fashion, starting from the bottom up, of "hit" data. Each layer represents the frequency range chopped up into approximately 4.2 million channels each 0.6Hz wide (if you multiply 0.6 x 4.2 million you get approximately 2.5 MHz). Each of the 14 boards is identical so therefore 0.6 x 4.2 million x 14 = 35.28 MHz, split between two eyes equals 17.64 00 MHz chunks of data scanned simulaneously. (By the way, 4.2 million channels x 14 = 58.8 million channels in total). All the straight lines you see are Radio Frequency Interference. The green and blue strip is neutral hydrogen - for an explanation of why we concentrate our search in this area see the Southern SERENDIP page.
For the technically minded: The multibeam receiver has 26 independent channels driven by 13 dual polarisation horn fed beams. The horns are attached to 26 low noise amplifiers (two orthogonal polarisations per beam) which are cryogenically cooled in a dewar above the horns providing a measured system noise temperature of < 25K. The receiver has been designed to cover the approximate frequency range of 1.2-1.5 GHz down mixed to an IF of 50-350MHz. Each beam has a typical width of approximately 14 arc minutes and a system sensitivity with a 600 second integration time at the 5 detection limit of 20 mJy per channel width (62.5 kHz). (Ain De Horta, Southern SERENDIP Project Scientist).