Question 2) Continued 12 13,14 15 No 16 17 Have 32 channel spectrum analyzer and 1024 channel autocorrelator. Planned: 1024 autocorrelator with minimum channel width of 200Hz Planned: 50 channel 10kHz bandwidth filter. Question 3) Could astronomical research benefit from simultaneous multi-channel analyzers with 106 to 109 channels of 1Hz width? Comments? Respondent: #1,2,3, 4,5 6 7 8 9 10 11 12 13 14 15 16 17 Yes For most spectroscopy 1kHz resolution is sufficient; the more channels the better. 100-yes 109-don't know Yes 106-109 channels would over resolve spectral features Yes Do not forsee uses for such high frequency No astronomical need for frequency resolution 100Hz. Question 4) Comment on the present state of the art of such systems. What characteristics would you require? How would you proceed to achieve them? What directions of development seem to you to offer most promise? 14 Feasible, using autocorrelators - Achieve very narrow resolution through use of autocorrelation Autocorrelators or multifilters for 1-100mhz total coverage. Increase the usefulness of such a spectrometer if it could 13 Working continuously on fine time resolution from weak signals after removing interstellar dispersion. Autocorrelator techniques to achieve such large capacity. Problem with 106-109 multi channel analyzers is the drift of the center of frequency of each channel; shouldn't exceed 20.1 Hz. 15 16 17 For VLA spectral-line back end, a system is contemplated 2 approaches a) coherent optical processing method Question 5) If such an analyzer were made available to you would you consider using it, via an IF tap or with spare receivers, to "hitch a ride" for coherent signal search during normal observing time? 8 9 Best to use antennas with large collecting area. 10,11,12 13 14 Yes Concerning technical improvements in pulsar observations: versatile very fast digital processing unit to perform the dispersion removal over wide bandwidths. Yes Have you ever engaged in any search for coherent or reported? vations? Explain. 17 3 searches: No a) OZMA/Drake b) Verschuur c) Palmer and Zuckerman (unpublished) Search for electromagneitc pulses from the galactic center. Yes No Yes; searching for narrow-band radiation near the hydrogen line. |