IPAC 2MASS Working Group Meeting #92 Minutes
IPAC 2MASS Working Group Meeting #92 Minutes, 4/09/96
Attendees: R. Beck, T. Chester, R. Cutri, T. Evans, J. Fowler,
L. Fullmer, G. Kopan, B. Light, H. McCallon,
J. Rosenberg, S. Wheelock
- Action Items From the PS CDR
- Project Status Updates
- Memory Upgrades
- Inputs to the QUALITY Subsystem
- Action Items From the PS CDR --
Due dates for the Action Items from the Point Source CDR have been
renegotiated in a telecon with NASA Headquarters. R. Cutri will distribute a
new list with due dates. Cognizant engineers are requested to review these
dates and respond to R. Cutri if any problems are apparent. The closure
mechanism for action items remains an email memo to R. Cutri with "cc:
2mass" explaining how the item was closed. Subsystem liens can be closed by
making the appropriate modifications to the software and documentation and
- Project Status Updates -- R. Cutri reported on
several updates to the project status as follows.
Memory Upgrades --
Since the new hardware configuration involves 8 ultrasparc CPUs for the
production cluster instead of 24 Sparc/1000 CPUs, some concern has developed
over the amount of memory per CPU. This was resolved for the production
cluster in this discussion, which concluded that doubling the memory per CPU
was prudent and not very expensive, so that the configuration is now seen as
two machines with 4 CPUs each and 512 MBytes of high speed memory each.
- A contract for the second telescope has been signed.
- The first telescope is on schedule for completion by December '96,
with a possible slip of about a month to have the mirror overcoated
with silicon dioxide.
- J. Huchra is meeting with the Forest Service to clarify the
Mt. Hopkins constraints.
- A snag has developed in the MOU with NOAO involving an
indemnification clause for design errors by UMASS.
- There are now three working engineering camera arrays.
- The flexure problem reported at the CDR has been traced to the
array translation stages, which will be replaced with fixed mounts.
- The image distortion has been traced to a phenomenon in the
electronics; this was found by rotating the arrays and noting that the
distortion retained its orientation with respect to the arrays, not the
- Science-grade arrays will be used for the May-June observing run.
It was not clear whether similar upgrades were needed for the analysis
and data base machines. T. Evans agreed to review the needs with B. Narron
and issue a report.
Inputs to the QUALITY Subsystem --
Since the system integration is drawing nearer, it is time to organize
the system wide information flow into the QUALITY subsystem. It is too early
to request SIS level definitions of the information from each subsystem, and
in fact very detailed definitions would be a bit premature at this time, but
a prioritized list of possible types of information should be formulated by
each cognizant engineer. These lists will be discussed at a working group
meeting in a week or two. The guidelines for development of the interfaces
are as follows.
- Table file format should be used unless clearly inappropriate.
- The great majority of analysis should be done in the generating
subsystem, with a relatively reduced number of parameters going to the
QUALITY subsystem, rather than having large dumps of possibly
interesting parameters flowing through the system. The latter should
be confined to the subsystems' own propietary file set.
- Limits on certain parameters, as well as other types of
information, will need to be encoded in the NAMELIST input to QUALITY,
implying an usual amount of involvement in that subsystem by cognizant
engineers of other subsystems.