Subject: Re: Observing Models TS work scope planning sheet
Date: Tuesday, March 13, 2007 6:27 PM
From: Richard Dekany <rgd@astro.caltech.edu>
To: David Le Mignant <davidl@keck.hawaii.edu>
Cc: Peter Wizinowich <peterw@keck.hawaii.edu>, Claire Max <cemax@ucsc.edu>, Don Gavel <gavel@ucolick.org>
Conversation: Observing Models TS work scope planning sheet

Hi, David,

Thanks for catching me up.  I've read the draft, which is both  
informative and, I feel, frame a number of very cogent arguments.   
I'm reassured that your draft is incorporating specific constraints  
of our community, though I concur with many of Bob's tempering comments.

What I would like to do here, however, is to encourage you to  
additionally address a number of NGAO-specific architecture and  
design issues.  The points you raise regarding archiving and an  
efficient suite of operations tools are important ones, and must be  
tracked going forward (when even during the SD phase, we'll address  
software issues more systematically).  However, I'd suggest that  
there are a few issues that will fold into our architecture choices  
in the next 3-4 months, where your perspective would be appreciated.

Namely, for the various observing models you identify in your draft  
document, how would the response to each of these questions differ  
(if at all between different modes?):

*	How often would instrument changes be necessary?

*	What combinations of NGAO instruments would need to be kept "hot"  
in order for each model to fully exploit its particular advantages?
		Would this require multiple support experts to be kept "hot", ready  
to observe with different instruments?
		What would be an acceptable switching time between instruments?

*	What feedback from the NGAO system or from the NGAO instruments  
would be needed to trigger a change to the observing program?
		Should this rely exclusively on science data, or could NGAO  
telemetry serve as a proxy for instrument performance?
		What external information would need to be continuously available  
(e.g. monitoring isoplanatic angle with a MASS, even when observing  
with a narrow-field instrument which is blind to anisoplanatism)
			What level of calibration and/or redundancy on external monitors  
would be required?  How rapidly do the advantages of a queue, for  
example, break down if the MASS unit begins reporting erroneous Cn2 
(h) values?

*	It is likely that rapid switching of instruments will lead to  
compromises in terms of wavelength and amplitude division (e.g.  
sharing IR light between tip/tilt sensors and IR science  
instruments).  Are there correlations between the criteria that might  
be employed to switch science programs due to near-term seeing  
forecasts, and criteria on fully optimizing sky coverage, or bright  
star Strehl, or some other AO performance metric.  A simple (too  
simple?) example might be that in the very best conditions, you  
switch to your bluest wavelength program.  In this case, you'd  
probably not want to find that you're sending all lambda < 588 nm to  
the Truth WFS (as one example).  I'm not quite sure how to elucidate  
this issue, but there seem to me to be a whole set of concerns which  
boil down to "having the configuration you want, when you want it."

(Your past work on assembling the Observing Scenarios may reveal  
additional architecture issues that I haven't captured here.)

Guidance from this study pointing (as far as possible) toward these  
NGAO-specific configurational issues (even more so than the cost/ 
science benefit issues, which have more time to sort out), would be  
of particular use as inputs to this Summer's architecture and design  
activities.

Cheers,
Rich

On Mar 13, 2007, at 5:36 PM, David Le Mignant wrote:

> Hello,
>
> Rich has are very good and valid questions for the science operations
> models. I have started to work on some aspects of it as you can see  
> here:
>  http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/ 
> ObservingEffici
> ency
>  There is a 12-page draft document posted as well as 4-page  
> comments from
> Bob Goodrich.
>  We definitely got the ball rolling, and it appeared clear to us  
> that we
> will not convert the Keck Observatory into Service Observing mode;  
> Yet we
> could recommend schema and changes to the current operation model  
> that would
> allow for more flexibility.
>
>  I was thinking integration Bob's comments and talking with Jason here
> before submitting a version 1.0 to you guys.
>
>  Does that sounds like a reasonable approach and time allocation?
>
> Thank you,
> David
>
> On 3/13/07 3:22 PM, "Richard Dekany" <rgd@astro.caltech.edu> wrote:
>
>> Hi, Peter,
>>
>> Sorry for the delay.  I like David's description and support the WSPS
>> as written.  My concern is that I've not understood how the output of
>> this effort will be considered by both the project and the
>> Observatory.  Are we actually empowered to adopt a non-traditional
>> observing model (namely, can we make NGAO design choices based on a
>> non-traditional observing model)?
>>
>> This issue seems perennial, with glacial change in the mindset of
>> most users (either for or against).  What, if anything, can NGAO do
>> (differently?) at the Observatory level to reach an appropriate
>> operations assumption prior to, say, this Fall when NGAO basic issues
>> will be largely solidifying?  My concern is that there is
>> insufficient human energy to make the science case this year, so
>> we'll end up assuming for NGAO a traditional model, but not
>> precluding queue operation.  If there is no way to avoid this
>> conclusion (am I too fatalistic?), is the timing of this study
>> correct, given the other studies competing for David's time (Your
>> opinion, David, is of course very welcome.)
>>
>> -- Rich
>>
>> On Feb 13, 2007, at 3:37 PM, Peter Wizinowich wrote:
>>
>>> Dear All,
>>>
>>> I am prepared to approve the attached work scope plan (see the minor
>>> edits to the attached version).
>>>
>>> We need Rich's review/approval as well for this WBS.
>>>
>>> I would also like to make sure that Claire takes a look at this  
>>> since
>>> the observing model is so tied to the science.
>>>
>>> Thanks,
>>> Peter
>>>
>>> -----Original Message-----
>>> From: David Le Mignant
>>> Sent: Thursday, February 01, 2007 2:00 PM
>>> To: Peter Wizinowich; Richard Dekany
>>> Subject: Observing Models TS work scope planning sheet
>>>
>>> Hello,
>>>
>>>  FYI, I have posted a draft on the twiki page.
>>>
>>> http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/
>>> WorkProducts
>>>  And I attach it to this message as well.
>>>
>>>  Your comments are welcome.
>>>
>>> Thank you,
>>>
>>> David
>>>
>>> <3.1.2.1.10_ObservingModelTS.doc>
>>