[mmaimcal] Re: Draft summary of ALMA low frequency issues

[John Carlstrom]

Dear Steve,

Greetings from the South Pole! I just read through the draft you
circulated (4 page version). You cover the basic points. I would
point out, as you did, that the point source sensitivity of
ALMA at Ka-band would be comparable to the upgraded VLA. But
that for surveys - it would be at least 4 times faster. Keep in 
mind that this comparison is made after putting of order $75M
into the VLA, While it cost only about $3.5M additional
for ALMA.  I think this should be mentioned up front in your
science bullets. 

As you know, I think it the case for keeping the  Ka-Band capabilities
in ALMA is overwhelming. At arcminute scales, the sensitivity
would be of order 3 uK in an hour! This is the required sensitivity
at the correct angular scales for investigating the reionization
history of the universe. In calculating this sensitivity I
used the number of baselines equal to 2.N with N = 64, to
account properly for the number of short baselines. 


Cheers, John

On Fri, 10 Dec 1999, Steven T. Myers wrote:

> 
> You can find a brief (4 page) draft of the summary for 
>   "Issues for the 30-46 GHz band on ALMA"
> at
> 
>   http://www.aoc.nrao.edu/~smyers/alma/alma43ghz-summary.ps
> 
> I will be working on the larger document over the weekend and into next
> week, and will make it available on my ALMA page
> 
>   http://www.aoc.nrao.edu/~smyers/alma/
> 
> then.  I hope this is a start for your discussions on Monday.
> 
>    -Steve
> 
> -------------------------------------------------------------------------
> |:| Steven T. Myers                      |:|  Associate Scientist      |:|
> |:| National Radio Astronomy Observatory |:|                           |:|
> |:| P.O. Box O                           |:|  1003 Lopezville Rd.      |:|
> |:| Socorro, NM 87801                    |:|  Ph:  (505) 835-7294      |:|
> |:| smyers at nrao.edu                      |:|  FAX: (505) 835-7027      |:|
> |:| http://www.aoc.nrao.edu/~smyers      |:|                           |:|
> -------------------------------------------------------------------------
> 
>