LSST Science Advisory Committee
	   Phonecon minutes, January 20, 2014

Attending: Zeljko Ivezic (U. Washington; LSST Project Scientist),
David Kirkby (UC Irvine), Mansi Kasliwal (Carnegie Observatories),
Lisa Hunter (UC Santa Cruz), Beth Willman (Haverford), Steve Kahn
(SLAC; LSST Director), Renu Malhotra (U. Arizona), Niel Brandt (Penn
State), Harry Ferguson (STScI), Jason Kalirai (STScI), Bhuvnesh Jain
(U. Penn), Lucianne Walkowicz (Princeton), Rachel Mandelbaum (Carnegie
Mellon), Michael Strauss (Princeton; SAC chair).

 This was the first meeting of the newly constituted LSST Science
 Advisory Committee.

 Steve: Thanks to everyone for joining the SAC.  The SAC is the
 primary
 vehicle for interface of the LSST Project with the external
 scientific community, which will become increasingly important as
 LSST construction starts.  The SAC advises Steve as Director.  The
 SAC sets its own agenda, and can/should call upon various people
 within the LSST Project to report to it.

 We will meet monthly by phone, with 2 face-to-face meetings per
 year.   We will advertise the existence and membership of the SAC to
 the community (e.g., by posting an announcement to the AAS
 newsletter).  People from the community will be encouraged to
 contact SAC members individually with their concerns, questions and
 ideas.  Our proceedings and activities should be open and visible,
 with minutes made public.  We will set up a webpage on lsst.org for
 this.

 The 2014 Omnibus spending bill passed by Congress specifically lists
 LSST, allowing us to get started on the construction and
 distributing bids for major components.

  Steve attended a recent meeting sponsored by the Kavli Foundation
  of directors of major ground-based telescopes.  They are planning a
  meeting, perhaps in May or June, of the LSST, TMT, GMT, Magellan,
  Gemini, and Keck SAC to discuss the synergy of these facilities,
  and how they might work together as a system.

********** Science issues within the project

 Zeljko: Some of the technical issues with science impact being
 discussed within the project include:
   -We're converging on the specifications of the LSST bandpasses.
   -We're exploring the ability to do very short exposures, perhaps
     as short as 0.1 sec.  This would allow us to observe into
     twilight.
   -We've initiated a series of workshops on LSST cadence.  The first
     meeting will happen August 10-15 in Tucson, piggy-backed onto the
     All-Hands meeting (we might also plan a face-to-face meeting of
     this
     group at that time).   In this context, Mario Juric (LSST Data
     Management Project Scientist) and Andy Connolly (heading the
     LSST simulations team) have developed a new approach to orbital
     linking of asteroids.  The current cadence requires that a given
     field be visited twice on a given night to determine each
     asteroid's local velocity vector.  The so-called 'universal
     cadence' is designed to do just that.  Mario and Andy's new
     approach can derive orbital solutions with only a single visit
     per night; if this works in practice, this could greatly expand
     the world of possible cadences.
      The cadence will be an algorithm that decides the sequence of
    observations on a given night.  (At the moment, we are unaware of
    any restrictions from the hardware on "reasonable" cadence
    choices).  One topic this group will discuss will be alternative
    modes of operations, including responding to targets of
    opportunity.
  -The SDSS imaging pipelines are now roughly at the level of the
    SDSS photo pipeline.  It is now being used on SDSS Stripe 82 and
    Hyper Suprime-Cam on Subaru.
  -There are two relevant meetings coming up.  Princeton will host a
    workshop on SDSS Stripe 82 (March 17-19; let Michael know if
    you're interested), and Fermilab will host a workshop on synergy
    between the Dark Energy Survey and LSST (March 24-27).

******* Some past history and context: 
 Steve: The concept for LSST has been developed over a number of
 years.  In 2003, the LSST Corporation was created, with the goal of
 launching the LSST Project.  LSSTC comprises ~35 institutions,
 mostly in the US, at the moment.  The LSSTC Board, with
 representation from all those institutions, meets monthly by phone,
 and face-to-face twice a year.  It has been mostly focused on
 policy and advocacy of the project.

 The LSSTC was not deemed eligible by the NSF to build LSST itself.
Rather, the oversight of this job was given to AURA.  The LSST Project
Office (centered in Tucson) is thus an AURA center, funded from NSF
and DOE (and private funds).  There is a separate AURA management
council.

 Now that AURA and the LSST Project Office are responsible for LSST
construction, the LSSTC sees as its job the science optimization of
LSST.  As such, it of course has great interest in the activities of
the SAC, and indeed formally approved the membership of this group.
They collect $1M in dues from member institutions per year, which they
plan to use (among other things) for holding workshops on various
aspects of LSST science preparation, and to educate the community
about the project.

 While the SAC is outward-looking, representing the connection of the
 project to the community, there is also a "Project Science Team",
 which Zeljko chairs.  The PST is made up of LSST Project personnel,
 and is the body that helps make technical decisions of scientific
 import internal to the project.

The LSST design is now quite mature.  The Science Requirements
document was written around 2007, and was used to flow down the
technical requirements of the telescope, camera, and data systems.
The SRD may be found here:
 http://www.lsst.org/files/docs/SRD.pdf

 The LSST Science Collaborations (11 in number; see the list at the
 bottom of http://www.lsst.org/lsst/science/participate )
 have contributed enormously to the scientific design of LSST, and
 played a key role in developing the science case for the project.
 They are now becoming more independent of the LSST Project,
 responsible
 for their own membership, and focused on preparing to do science
 with the data once it starts to flow.

 The LSST Project Office must be focussed on construction.  While it
is not yet decided exactly which will be in charge of LSST operations
(AURA?  LSSTC?), much of the LSST construction team will be involved
in operations.

 LSST is a world-unique project.  The funding for construction is
almost entirely coming from the US (a small piece from France).  But
during operations, the funding will have a major international
component.  The MREFC ("Major Research Equipment and. Facilities
Construction', the pot of money within NSF funding construction) can't
be used for operations (or supporting science, for that matter).
While the NSF and DOE will support most of the operations costs, we're
short about $10M/year for operations, which we will raise
internationally.  We have letters of intent with many international
partners, including the United Kingdom, France, China, South Korea,
South Africa, Brazil.  Memoranda of Understanding (MOUs) are being
developed with various national consortia and individual
institutions.   Once an institution has signed such an MOU, its
members may apply to join individual science collaborations.  Steve
guesses that this may lead to an approximate doubling of their size.

 The construction costs include $488M from the NSF, $165M from the
 DOE, and $40M (most already spent) from private sources.

 The SAC will have a lot of visibility to the funding agencies.  We
 should consider inviting representatives from the funding agencies
 to join our meeting.  The SAC can and should take an active stance
 in the project.

 The current schedule has the camera being mounted on the telescope
in mid- to late 2020.  There would then follow 6 months-1 year of
engineering commissioning, then 1 year of science commisioning.  The
official start of the 10-year survey is late 2022.  There would be
annual releases of fully processed data, with other data products
available on shorter timescales, including processed images and
alerts. We want to engage the community in the commissioning process,
but are still working out the details.

 We discussed how decisions get made within the project.  The SAC is
 advisory only, but if it really doesn't like how things are going
 (e.g., if there is a major disagreement between it and the PST on
 some issue), it is empowered to be very public about the
 disagreement.

 This group's first face-to-face meeting will be in Princeton; we need
 a few more people to fill out the doodle poll, and I'll set the date.