The LBTO software and IT group was originally responsible for development of the Telescope Control System (TCS) software, and build-out of observatory Information Technology (IT) infrastructure. With major construction phases of the observatory mostly completed, emphasis is transitioning toward instrument software handover support, IT infrastructure obsolescence upgrades, and software development in support of efficient operations. This paper discusses recent software and IT group activities, metrics, issues, some lessons learned, and a near-term development road-map for support of efficient operations.
The Large Binocular Telescope (LBT) has eight Acquisition, Guiding, and wavefront Sensing Units (AGw units). They provide guiding and wavefront sensing capability at eight different locations at both direct and bent Gregorian focal stations. Recent additions of focal stations for PEPSI and MODS instruments doubled the number of focal stations in use including respective motion, camera controller server computers, and software infrastructure communicating with Guiding Control Subsystem (GCS). This paper describes the improvements made to the LBT GCS and explains how these changes have led to better maintainability and contributed to increased reliability. This paper also discusses the current GCS status and reviews potential upgrades to further improve its performance.
Characterisation, mitigation and correction of telescope vibrations have proven to be crucial for the performance
of astronomical infrared interferometers. The project teams of the interferometers for the LBT, LINC-NIRVANA
and LBTI, and LBT Observatory (LBTO) have embarked on a joint effort to implement an accelerometer-based
vibration measurement system distributed over the optical elements of the LBT. OVMS, the Optical Path
Difference and Vibration Monitoring System will serve to (i) ensure conditions suitable for adaptive optics
(AO) and interferometric (IF) observations and (ii) utilize vibration information, converted into tip-tilt and
optical path difference data, in the control strategies of the LBT adaptive secondary mirrors and the beam
combining interferometers. The system hardware is mainly developed by Steward Observatory's LBTI team and
its installation at the LBT is underway. The OVMS software development and associated computer infrastructure
is the responsibility of the LINC-NIRVANA team at MPIA Heidelberg. Initially, the OVMS will fill a data archive
provided by LBTO that will be used to study vibration data and correlate them with telescope movements and
environmental parameters thereby identifiying sources of vibrations and to eliminate or mitigate them. Data
display tools will help LBTO staff to keep vibrations within predefined thresholds for quiet conditions for AO
and IF observations. Later-on real-time data from the OVMS will be fed into the control loops of the AO systems
and IF instruments in order to permit the correction of vibration signals with frequencies up to 450 Hz.
We outline the design considerations and principles for developing a graphical user interface for configuring and
operating Large Binocular Telescope Interferometer (LBTI) on sky, and examine the "weblication" methodology to
deliver this astronomical software over the web. LBTI is an instrument to be installed at the Large Binocular Telescope
to search for exo-planets. The instrument consists of a universal beam combiner to combine the light from both arms of
the LBT, an L and M band science camera, a K band nulling channel along with wave front sensor units for adaptive
optics correction. Additionally, the application will have an interface to the telescope control system and XML based
telescope telemetry data flow.
The Large Binocular Telescope Interferometer, a thermal infrared imager and nulling interferometer for the LBT, is
currently being integrated and tested at Steward Observatory. The system consists of a general purpose or universal
beamcombiner (UBC) and three camera ports, one of which is populated currently by the Nulling and Imaging Camera
(NIC). Wavefront sensing is carried out using pyramid-based "W" units developed at Arcetri Observatory. The system
is designed for high spatial resolution, high dynamic range imaging in the thermal infrared. A key project for the
program is to survey nearby stars for debris disks down to levels which may obscure detection of Earth-like planets.
During 2007-2008 the UBC portion of the LBTI was assembled and tested at Steward Observatory. Initial integration of
the system with the LBT is currently in progress as the W units and NIC are being completed in parallel.
LBTI is a thermal imager and a nulling interferometer to be installed on the Large Binocular Telescope (LBT). Here,
we present the distributed component architecture model and its simple yet powerful software structure designed to
complement the LBTI hardware model that comprises pyramid wave front sensors with its control electronic universal
beam combiner, phase sensor, science imager, and all housekeeping duties to run the cryogenics, compressors, vibration
monitors and the interface to the telescope control systems.
Presented is the design of a nulling interferometer testbed which is capable of maintaining the suppression of a
broadband, infrared source in the presence of external perturbations. Pathlength stability is accomplished by
introducing a dispersive phase shift which allows light at a SWIR band to be used as a wavefront sensor to stabilize the
nulled output of a broadband MWIR channel. Since both channels are common path, fluctuations in OPD observed
with the wavefront sensor directly correlate to fluctuations of the nulling passband. Results obtained from the testbed
will be useful to future nulling interferometers such as the Large Binocular Telescope Interferometer and the Terrestrial
Planet Finder Interferometer which are currently being designed to aid in the search for earth-like planets outside our