MLSO
-Instruments-
The Mauna Loa Solar Observatory (MLSO) resides in a lava field on the northwest
flank of Mauna Loa (elevation 3353 m) on the island of Hawaii. This site
provides some of the best solar observing conditions in the world. MLSO
currently provides data for three observing programs: ACOS (Advanced Coronal
Observing System), PSPT, and ECHO. ACOS includes the following instruments:
Mark-IV (K-coronameter), the Polarimeter for Inner Coronal Studies (PICS)
(Hα: 656.3 nm, disc and limb), and the Chromospheric He I Imaging Photometer
(CHIP) (Helium-I: 1083 nm, disc).
-Operations-
In 2002, MLSO was designated an NCAR facility, making it possible for a 3rd
observer to be hired (January 2003), and to add 4 hours to the daily observing
schedule. Mauna Loa instruments currently operate between 17:00 - 02:30 UT, weather
permitting, and barring observer sick time. The number of
coronal mass ejections (CMEs) observed with
the Mark-IV white light coronameter has nearly doubled between 2002 and 2003,
despite the slight decline in solar activity. Mark-IV white light observations
of the low corona are unique, and the increased number of observed CMEs can
greatly improve the physical understanding of the initiation of these events
and their interaction with the surrounding solar atmosphere.
The number of observing days during which MLSO acquired data in the past
two years was:
Instrument 2002 [2 observers] 2003 [3 observers]
CHIP: 310 days (85%) 347 days (95%)
PICS: 284 days (78%) 345 days (95%)
Mark-IV: 246 days (67%) 307 days (84%)
A significant increase in daily 'duty cycle' for each instrument is
evident since MLSO extended its observing schedule. Furthermore, in 2003,
there were 211 days when observations were taken beyond 00:00 GMT. For most
of those days,
the observations ran to 02:00 UT or beyond. Prior to 2003, MLSO observations
typically ended between 22:00 and 23:00 UT. This means that MLSO now provides
a significant number of days with observations that overlap Australia, Japan
and China for 3-5 hours.
-Datasets-
Since acquiring a DVD "juke-box" storage system in 2002, MLSO is now able to
provide easy access (via the MLSO web site) to all recent ACOS data
(2001 - 2004). Despite a reduction in MLSO data processing support staff
this year, and the large increase in observations (due to extended observing
hours), HAO is continuing to provide the community with fully-processed data
in a timely manner. In addition, HAO is slowly continuing to add older ACOS
data (prior to year 2001) to its DVD storage system.
On-demand access to the entire ACOS dataset collection via the MLSO
web site will eventually be provided.
The data archiving scheme has allowed MLSO to become one of the first beta test
cases for the Virtual Solar Observatory project, a joint effort (Stanford
University, National Solar Observatory, Montana State University, and the
Solar Data Analysis Center) initiated via a proposal in November, 2002.
-Additional Coronal Data from the MLSO Website - Solar Maximum Mission-
The MLSO image catalog database (MySQL) now provides data searches which
are quick and complex. It also makes it relatively easy to add new
observational datasets. HAO is currently making preparations to store
Mark-III K-coronameter (1980 - 1989) and Solar Maximum Mission Coronagraph
(1980, 1984-1989) data on the DVD archive.
HAO recently received a NASA grant (LWS03-0161-0051) to provide all Solar
Maximum Mission (SMM) coronagraph observations to the community, utilizing
the MLSO web site resources. The SMM coronagraph operated during 1980 and
from 1984 through 1989, recording over 240,000 images of the white-light
corona, and more than 1,300 CMEs over most of a solar
cycle. The complete SMM coronagraph dataset will be available to the
scientific community by the spring of 2005.
-Instrument Upgrades-
Two instrument upgrades are in progress:
a. A sky brightness monitor from the University of Hawaii is soon to be
installed at MLSO as an aid in calibrating the MLSO sky transmission
telescope. High quality sky transmission readings are needed to help
ensure the quality of the MK4 calibration. MLSO and HAO staffs are
currently creating the infrastructure needed to support the new monitor.
This effort has been delayed until the completion of the ATST site survey.
b. MK4 01 guider electronics are being completely redesigned by MLSO
observer Allen Stueben and the HAO instrumentation group. Fabrication
has begun and the new hardware will be installed soon. This should
significantly improve the MK4 pointing which is currently the largest
source of error in the Mark-IV calibration.
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PSPT
 The Precision Solar Photometric Telescope
(PSPT) group at HAO has stabilized the telescope hardware and data
processing algorithms. The new flat-field algorithm, with improved
convergence using prime number offsets (see accompanying Figure), has been
implemented as the default, and reprocessing of the full data set using
it has begun. The past year has seen continued support of the SORCE
mission and SFO collaboration with daily observations. Additionally, 117
data files have been delivered in response to specific requests; in one case,
10 GB of data was delivered in response to one user's request for a full
month of observations. A MOU with the Rome observatory has been
finalized, including a collaboration aimed at creating a common PSPT
data base. Work has also begun to include PSPT data in the ACOS/MLSO
data-search web-page.
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