[asac][almanews] ALMA Memo 488 Released

[Stacy Oliver]

ALMA Memo # 488

 

Wide-Field Imaging of ALMA with the Atacama Compact Array: Imaging
Simulations

 

Takahiro Tsutsumi(NAOJ), Koh-Ichiro Morita(NAOJ), Tetsuo Hasegawa(NAOJ),
Jerome Pety(IRAM/Obs. de Paris)

 

2004-03-21

 

Keywords: mosaicing, wide-field imaging, simulations, ACA

 

We examined the significance of the Atacama Compact Array (ACA) in
wide-field imaging of ALMA through imaging simulations.  The purpose of
the simulations are to:

 i) demonstrate importance of ACA in wide-field imaging with ALMA and

 ii) identify which component of errors has more significant influence
than others on quality of final images obtained with ALMA+ACA  using
realistic parameters as to give feedback on designing and specifications
of the ACA system. We particularly focused on the following aspects:
difference on the ACA configuration design and effects of pointing
errors, amplitude errors, and atmospheric phase errors. The simulations
indicate that how densely packed the ACA configuration is an important
factor for good imaging performance. The pointing errors at submm waves
seriously degrade fidelity of an image. The atmospheric phase
fluctuation also plays a major role. As indicated by previous works, our
study indicates that ACA can boost the quality of wide-field imaging
with ALMA by a factor of two or more for many cases, while dependency on
structures of model images exists. In presence of all the errors, the
projected goal of the imaging fidelity of 20 or better for ALMA when ACA
is included, can be achieved if the current specifications are met.

 

View a pdf version of ALMA Memo #488. 

http://www.alma.nrao.edu/memos/html-memos/alma488/memo488.pdf

 

 

 

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