[asac] [almanews] ALMA Memo 391 Released

[Stacy Oliver]

ALMA Memo #391

A Square Wave Phase-Switching Scheme for a Large Number of Antennas.

A.R.Thompson and L.R. D’Addario

2001-08-31

The complete set of square waves with frequencies that are integral
multiples of a unit frequency cannot be used for phase switching since such
a set are not mutually orthogonal,as discussed in ALMA Memos 287 and 385.
However,by recognizing that absolute mathematical orthogonality is not
required,and by selecting a sub-set of square-waves of certain frequencies,
it is possible to design a practical phase switching scheme. Compared to the
use of Walsh functions,this scheme has the advantage that the values of
cross correlation between pairs of square waves remain very small in the
presence of arbitrary relative time shifts.


View a pdf version of ALMA Memo 391.
http://www.alma.nrao.edu/memos/html-memos/alma391/memo391.pdf

Download a ps version of ALMA Memo 391.
http://www.alma.nrao.edu/memos/html-memos/alma391/memo391.ps



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