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Freq. profile diff. between ACA and 64-Antenna Correlator Abstract

by Dong-Chan Kim last modified Apr 25, 2011 by Pat Murphy

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ALMA Memo # 580


Frequency profile difference between ACA Correlator and 64-Antenna Correlator

Kamazaki, T., Okumura, S. K., Chikada, Y.

2008-09-18

ACA Correlator and 64-Antenna Correlator adopt FX and XF architecture, respectively. This difference introduces different frequency responses between them. However, for combined imaging of the ACA and the 12m-Array data, their frequency profile compatibility is required, and one possible method is the convolution of weighting function in the frequency domain. We have studied this method and found that "a XF frequency response convolved with Hanning window function" is well synthesized by linear combination of "twelve FX frequency responses", when one frequency channel width of the 64-Antenna Correlator is two times as large as that of the ACA Correlator. Then, we have calculated frequency profiles by convolving synthesized and original frequency responses with several object profiles. The maximum profile difference between them is estimated to be small by 0.6 % or less except for the case of d function as an object profile. .

View a pdf version of ALMA Memo #580.