Message boards :
Number crunching :
SODA, with a D
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DMMD Send message Joined: 14 Feb 00 Posts: 118 Credit: 71,564,960 RAC: 0 |
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Andy Lee Robinson Send message Joined: 8 Dec 05 Posts: 630 Credit: 59,973,836 RAC: 0 |
um... that should be Foxtrot Foxtrot Tango if you want to use the international convention... Interesting article, but pity that the graphic incorrectly sums the example waveforms, and appears to just be drawn! I'm not sure that sparse FFTs are applicable for SETI, as they are used for lossy compression of media. |
ML1 Send message Joined: 25 Nov 01 Posts: 20289 Credit: 7,508,002 RAC: 20 |
... I'm not sure that sparse FFTs are applicable for SETI, as they are used for lossy compression of media. FFTs are used extensively in the analysis algorithm... That is also an area that has been highly optimised to speed up the analysis. (A very powerful technique to move between the time domain and frequency domain...) Keep searchin', Martin See new freedom: Mageia Linux Take a look for yourself: Linux Format The Future is what We all make IT (GPLv3) |
Andy Lee Robinson Send message Joined: 8 Dec 05 Posts: 630 Credit: 59,973,836 RAC: 0 |
Thanks Martin, I do know what they are, where and why they are used! (I wrote an FFT algorithm in 6502 ASM to do digital vocoding amongst other things for my postgrad thesis 25 years ago!) This algorithm is not a lossless fast FFT, it economizes by throwing away insignificant frequencies and working on the rest. Not too useful for SETI where everything is significant - the faintest of signals may be overlooked and discarded. It might be useful for superficial scanning, then do a deeper search with the normal FFT. |
ML1 Send message Joined: 25 Nov 01 Posts: 20289 Credit: 7,508,002 RAC: 20 |
Thanks Martin, I do know what they are, where and why they are used! Sorry, missed the lowercase "sparse" and mind-clicked on the uppercase "FFT" and hit 'fire'! :-( ... sparse Fast Focus Telepathy? :-) Interesting note, thanks. Keep searchin', Martin See new freedom: Mageia Linux Take a look for yourself: Linux Format The Future is what We all make IT (GPLv3) |
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