Engineering Developments
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ENHANCEMENTS
DEVELOPMENTS ULTRADAS NAOMI COMPUTING INFRASTRUCTURE UPGRADE INGRID WHT MILLENNIUM UPGRADE LASER GUIDE STAR STUDY AUTOFIB 2 SMALL FIBRES CCD
PROCUREMENT ENHANCEMENTS The
following projects are funded by the joint PPARC/NWO budget and are
being undertaken by ING engineering groups, sometimes in collaboration
or with assistance from outside institutions. ULTRADAS The
ULTRADAS project embraces the production of a new data acquisition
system (DAS), and its implementation for all science detectors at ING
using the San Diego State University SDSU-2 CCD controller. Principle
gains from the project are faster readout speed, and improved
reliability - from both the
DAS system and CCD controller - together with reduced maintenance
requirements. The system
will ultimately use a PCI interface between the CCD controller and DAS
computer, however due to delivery delays is initially being implemented
using an S-BUS card. With
the S-BUS interface the system produces typically a threefold decrease
in un-windowed readout cycle time over previous ING systems, with the
PCI interface this will improve to sixfold, potentially offering an
overall 5% increase in overall telescope observing time. The
project is currently being expanded to include Infra-Red detectors in
support of INGRID, and eventually the LIRIS spectrograph being
developed by the IAC. ULTRADAS has been commissioned on the INT Wide
Field Camera and WHT Prime Focus 4Kx4K 2 Chip Mosaic. The commissioning
programme for the remaining ING detectors and focal stations is now
being planned, with rollout during 2000 expected and completion by the
end of 2001. COMPUTING
INFRASTRUCTURE UPGRADES To be added The
ING have embarked on a comprehensive upgrade of the William Herschel
Telescope involving replacing and enhancing many systems.
This programme embraces a number of projects and all engineering
groups are contributing. This
directly supports the NAOMI and INGRID projects but also
brings performance and reliability improvements to the WHT in support of
other instruments. Previous improvements include an Alpha computer based
Telescope Control System (TCS), the introduction of 4kx2k EEV-42
detectors and improved dome seeing through oil cooling. The programme includes: ·
New Observatory Control System to replace the existing Instrument
Control System for improved performance, ease of maintenance and
development, further increased commonality between subsystems and
reduced maintenance costs. Initially
the system will support ULTRADAS for faster CCD readout, and the
implementation of the 4kx4k two chip EEV-42 mosaic for use at prime
focus and on UES. Instrument
control will then be implemented sub-system by sub-system using DRAMA
and EPICS(channel access) with appropriate mimic displays until all
focal stations and instruments are converted.
This project will build on basic control to provide more complex
modes of observing - such as automatic guide star acquisition.
Finally it will provide an efficient queue-observing tool to
automate service observing. ·
New Autoguider. This will
be a DRAMA based system similar to the reliable INT system.
This autoguider will replace the existing FORTH based system that
runs on unreliable, obsolete and irreplaceable hardware. ·
New acquisition TV system will replace the existing, failing system with
a modern supportable system that offers improved performance.
Initially implemented as a stand-alone system the ultimate aim is
to integrate with other telescope systems. ·
Faster CCD readout through the ULTRADAS system. ·
A new UNIX based Guide star server will be implemented.
This work has been placed at the UKATC and it is expected it will
be based on the porting of an existing system. ·
The above improvements will remove several obsolete, failing and
unsupportable systems, including the network interface units (NIUs) and
Data Management System (DMS) both dependent on bespoke hardware and
software and both the causes of much lost time while requiring a large
support effort. ·
Improvements to GHRIL for NAOMI which include: ·
Reducing telescope vibration by tuning and modifying the oil damping
system with extra dampers near to the bearing surfaces. ·
A new cooling system with glycol lines routed through the telescope to
an external heat exchanger. This
system was installed and operated for the last ELECTRA run, it still
requires final commissioning and its planned extension to the UES cooler
- thus removing a further source of vibration in the telescope structure
and heat within the dome. ·
A new optical bench for NAOMI. The
previous two ELECTRA runs identified that the original, although
adequate for other instruments was insufficiently damped for NAOMI and
so will be replaced. ·
Improved access for instruments, including NAOMI through a roof hatch. ·
Improvements to GHRILL seeing by re-coating and adding CaF2 windows to
the infrared de-rotator. The
windows will prevent airflow through the unit eliminating turbulence in
the light path and stopping the deposition of dust on the reflecting
surfaces. Also airflow
within the optical bench room will be studied in an effort to understand
and improve local seeing. ·
Investigation of glitches in the telescope tracking/positioning seen by
ELECTRA AUTOFIB-2
SMALL FIBRES To
be added CCD
PROCUREMENT To be added DEVELOPMENTS The
following projects and are individually funded by PPARC and are being
undertaken by various collaborations as identified against each project. For
further information from ING engineering staff see the Engineering
Contacts page. NAOMI NAOMI
is a PPARC funded natural guide star adaptive optics system being
developed for the WHT by a collaboration between the Durham University
and the UKATC. This is a
common user system and will be located in the Nasmyth focus Ground based
High Resolution Imaging Laboratory (GHRIL). The
initial science detector for NAOMI is the near infrared camera INGRID The
ING are assisting in the NAOMI project especially in the preparation of
the WHT telescope and systems to support NAOMI including improvements to
telescope pointing, reduction of vibration, computer infrastructure and
software upgrades incorporated in the WHT Millennium Upgrade Further information is available from a description of NAOMI and the NAOMI home page INGRID INGRID
is a PPARC funded near infrared imaging camera, being developed for use
on the WHT in stand alone mode at folded Cassegrain focus and as the
NAOMI science detector at Nasmyth.
The camera uses a 1024x1024 HAWAII array HgCdTe detector that can
be cryogenically cooled either with liquid nitrogen or a helium closed
cycle cooler. Principle engineering features of the instrument are three
cryogenic filter/pupilstop wheels, the deployable pupil imager for
alignment. INGRID
was designed and manufactured by the now defunct Royal Greenwich
Observatory (RGO), Cambridge. After
the closure of the RGO, ING with assistance from the UKATC and IAC) took
on the responsibility for finishing the engineering work, testing,
scientific validation and commissioning
of INGRID. Key
stages carried out at ING are design, manufacture and optical alignment
of the high tolerance main lens holders and characterisation of the
science array. Production
of the INGRID support software has also been undertaken by ING.
Further
information is available from the INGRID homepage LASER
GUIDE STAR STUDY Currently
a WHT laser beacon preparatory study is taking place. This is a
collaboration between Imperial College, Durham University, UKATC and ING
and is funded by PPARC. It
involves the firing of a low power test laser from an ING facility on
the ORM site to create a laser beacon at an altitude of around 80km to
measure the time variation of the altitude and abundance of the
mesosphere sodium abundance.
The beacon is then detected by ING telescopes.
The first test firing was a success the beacon was successfully
created and imaged by the JKT. Follow
up tests are scheduled to determine seasonal variation. The
outcome of the project will be the production of a report with a full
scientific cost/benefit analysis for a full laser beacon upgrade to
NAOMI. |