# Presentation: 868253

## DES Supernova Farm Discussion

- SN Science Requirements
- Possible SN Farm Locations
- DES Council
- Discussion

## DES Supernova Farm Discussion

- The DES Council represents:
- 	FNAL NCSA NOAO
- Possible SN Farm Sites
- 	Cerro Tololo*, La Serena, NCSA, Fermilab
- The site choice implies responsibility which lasts for years.
- * The original idea

## Statements to spark Discussion (1)

- SN Farm Purpose: Inform people who update the plan for timely pointing of DECam and other instruments
- 	“timely” and “other instruments” must be driven by science
- Expect to have multiple SN in each 300 second exposure.
- Need concise statements informing the choice of site.
- The site choice implies who pays for equipment* which does not cost much compared to ongoing operational support by staff with appropriate expertise.
- * ~15 CPUs?

## Statements to spark Discussion (2)

- If La Serena, it will serve DES (5 years), but NOAO also serves others.
- In addition to bandwidth, one must consider
- 	priorities: DTS has no prioritization queue, NCSA serves many
- 	reliability: >99% CTIO to La Serena, <99% CTIO to Illinois
- 	cadence: many fits / night during ~six months of observing; then off
- 	timeliness: 1, 8, 18, 24 hours? <- need to specify science drivers
- More than one farm site
- 	backup for unplanned interruptions
- 	duplication of effort
- 	cost vs science benefit

## Backup

## Out-of-date DF to CS email

- From _[ ](View message header detail)_ David Finley <finley@fnal.gov> Sent Tuesday, April 1, 2008 3:48 pm
- To csmith@ctio.noao.edu Cc 'David Finley' <finley@fnal.gov> , 'John Marriner' _[marriner@fnal.gov](mailto:marriner@fnal.gov)_
- Subject DES SN Farm?Attachments _[winmail.dat](https://imapserver1.fnal.gov/attach/winmail.dat?sid=dicpW16qTok&mbox=DES%2FWG%20SN&uid=28&number=2&filename=winmail.dat)_7K Hello, Chris Smith: John Marriner asked me to look into whether the DES Supernova science program can be accomplished by using NCSA to do the "fast turnaround" analysis instead of using a computing farm at CTIO, as is the present plan (as I understand it).The considerations I am aware of are:1.    The SN data need turn-around in less than 24 hours so that the next night's pointing can be planned.  A very good goal would be an 8 hour turnaround from camera readout to presentation to the "planner for the next night".2.    If all is working well, the bandwidth for transmitting data from the camera to NCSA will not a problem.3.    The reliability of the connection between the camera and NCSA needs to be determined so "lost opportunities for proper pointing on the next night“ can be estimated.  The same consideration applies to timely access to NCSA.  Other DES data collection can afford a delay of a few days and not impact the science.  A delay of DES SN data analysis by a few days may represent lost opportunities.4.    The cost of the equipment for a SN Farm at CTIO is about $20K and thus (to my mind) not a real issue.5.    Writing the same software for use at NCSA and CTIO seems an inefficient use of programmer support.6.    Operating and maintaining a SN Farm at CTIO will require hardware and software maintenance, and these resources could be applied elsewhere.7.    A SN Farm would be needed anyway as a backup.  This sounds good, but its veractiy depends on the reliability and availability of the "camera to NCSA and back to Blanco" connection.He indicated we should talk.  I will be at the DES Collaboration meeting later this month, but I would like to get your perspective earlier than that.  So I have two questions:1.    Where should I look to get a clue on what it means to have the SN Farm at CTIO?2.    When is a good time for me to call you?Your phone number is listed as 56-51-205-214.  And according to _[http://](http://www.countrycallingcodes.com/)__[www.countrycallingcodes.com](http://www.countrycallingcodes.com/)__[/](http://www.countrycallingcodes.com/)_ it is 1524 in Chicago and 1624 in Chile.I'm also sending this to John Marriner in case he wants to comment / clarify the above.Thanks and Cheers.  Dave.Cc: John Marriner