Hello Serge and List, 1. You neglected to say what the important parameters are which you want to abstract from the collected data! 2. Some cetaceans and other sources go to at least 150 KKz. 3. You neglected to indicate the phase response you will need nor the error between the two channels in phase and amplitude. 4. The original purpose of Fourier methods was to look at what happens inside a KNOWN boundary NOT I repeat NOT to determine the values of a boundary. There are many errors to be expected in the results of frequency determinations using any of the current FFT methods. For single input frequencies to a FFT frequency errors of 10% have occured. Phase errors also occur!
5. The current best A/D converter (which I would use) is only 14 bits. It is the ANALOG DEVICES AD10465 A DUAL CHANNEL 14 BIY 65 MEGA-SAMPLES PER SECOND converter. I would use (if possible) IEEE 1394 VERSION 2. version 1 is not as fast as USB 2. There is an evaluation board available for the 10465 which I would recommend be incorporated into your front end. 6. For those interested in how to evaluate the output of an FFT (being used for frequency determination) routine let me know and I will post examples of pathologic cases. FRED -- Fred Herzfeld, MIT'54 78 Glynn Marsh Drive #59 Brunswick, Ga. 31525-0504 USA Tel: (912) 262-1276 Fax: (912) 262-1276 by request
