--- SimuWG members: 
  Reza Ansari, Jiao Zhang, Xin Wang
  Le Zhang 
  Qizhi Huang, Shifan Zuo and Qiuyuan Tian (NAOC)
  Yan Gong ( UC Irvine) 

---- A proposal for Dish Array strategy:
>> it seems that one should first stare at the region around the North Celestial Pole since:
1) for a drift scan this minimizes the total solid angle covered so the signal to noise 
per solid angle is maximized and one could "drill down" to a given signal level in the 
shortest period of time Ê
2) if you point all the dishes directly at the NCP then one covers 
the entire region in half a sidereal day (this is the period of the signal) and 
during winter this fits between dusk and dawn, one has no issue with the day-night boundary. 

>> Possible negatives are 
1) the signals appear in changes in the visibilities with relatively long periods: hours. Ê
Is there some problem on this timescale with 1/f noise or other drifts of some sort? ÊÊ
2) one would be 45 degrees from the horizon so slowly varying ground pick up might 
be a problem (certainly on hour timescales the ground temperature will vary) Ê
3) due to the limited sky coverage one would be sample variance limited Ê
4) does this step on 21CMA's toes?


>>>  There are some good reasons to point to the equator that I can think of - namely 
overlap with existing and future surveys (SDSS North and Equatorial Strip, DES 
will definitely go there). ÊThe downside is that for a fixed integration time the noise 
per solid angle is minimized at the equator (but maximized at the poles). Ê

Another strategy is to scan the zenith since this minimizes ground pickup. ÊÊ
Also for a given dish configuration the zenith also optimizes the angular resolution 
(in the altitude direction) which is degraded near the horizon.

Curiously since Dashankou is at roughly 45 degrees latitude the equator and the NCP 
are at nearly the same zenith angle. ÊÊOne might imagine writing a requirement 
for the dish configuration being that the dishes be able to operate 
(i.e. avoiding other dishes getting in to much in the side lobes) 
with zenith angle from, say 50 degrees to the north to 50 degrees 
to the south (adding 45+5=50, 5 degree "margin"). Ê