Date: Fri, 17 Oct 1997 09:31:07 -0700 (PDT)
Subject: 2MASS WG Mtg #133 Minutes

           IPAC 2MASS Working Group Meeting #133 Minutes

Attendees: R. Beck, R. Cutri, D. Engler, J. Fowler,
           T. Jarrett, D. Kirkpatrick, G. Kopan,
           H. McCallon, S. Wheelock, J. White


1.) Telescope and Camera Status
2.) Science Team Meeting
3.) 14-Bit Tests
4.) Disk Errors on Rodan
5.) Minor Planet Processing


1.) Telescope and Camera Status

    R. Cutri reported the following items: (a.) the southern
telescope has arrived safely in Santiago; (b.) laboratory dark
and flat sequences have been taken with the southern camera and
are on a tape due to arrive soon at IPAC; (c.) the northern
telescope's accuracy in pointing and tracking has been good
enough since the recent repairs to change the color of many items
in the web-based quality reports from red to green; (d.) the
increasingly cold weather on Mt. Hopkins has apparently evoked a
temperature-dependent astigmatic effect that has altered the
relationship between the bands in PSF behavior; (e.) the new
calibration strategy has now been in effect at the observatory
since last Friday; (f.) the 971005 tape received from the
northern observatory employed the new compression standard.

2.) Science Team Meeting

    R. Cutri announced that the next Science Team Meeting will be
in Boston on November 4-5 and will include parameter tuning as
one of its main agenda.

3.) 14-Bit Tests

    After several reruns to get exact duplication of conditions,
the 16-bit and 14-bit runs of 970608 have been completed, and
some reports have been received concerning differences. All the
early results have confirmed, e.g., dark noise increases at the
1% to 3% level, drops in source extraction, more single-band and
dubious band combinations (especially J and K with no H),
slightly higher coadd noise. The worst hit seems to be in galaxy
processing, where T. Jarrett reported magnitude discrepancies in
the 2% to 4% range. Analysis is continuing.

4.) Disk Errors on Rodan

    R. Beck reported that I/O errors have been occurring on the
"rawk" disk (where the raw K data are stored for pipeline
processing) and have gotten too bad to tolerate; a disk swap will
be performed.

5.) Minor Planet Processing

    J. Fowler reported that the MPCAT subsystem is finally ready
for testing. Early runs are encouraging, although an unexpectedly
large number of scan have no minor-planet predictions; this is
believed to be because most of the scans available online are
calibration scans and therefore have areas of only 1/6 square
degree, and a large number of scans are dedicated to the same
areas, most of which are not very close to the ecliptic. Much
more testing will be done, and the format of the associations
file will be changed from scan-oriented to observation-night-
oriented in order to reduce the number of files with no
predictions or associations in them.