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.
In the current report, we describe the structure of the telemetry logging system of the Large Binocular Telescope (LBT)
and its approach to telemeter registration. The telemetry logging system, called Telemetry, has three functions. It will
provide system data to LBT Observatory (LBTO) personnel in order to facilitate engineering activities such as
commissioning, failure diagnosis and system repair. In order to detect failures as soon as possible after they occur,
telemetry will allow for live monitoring of the functional status of key telescope systems. Finally, in order to help
personnel understand how the LBT operating characteristics evolve with time, telemetry will provide access to historical
telescope system data.
Given this range of functions, a key requirement of Telemetry is that it must easily adapt to new sources of data. To
minimize the changes required to Telemetry, it has no pre-existing knowledge about the structure of the data it will
collect. Instead, it engages in a telemeter registration process, in which the data source must describe its own structure.
This registration process requires no external data files to be maintained since the description is built up by a sequence of
function calls to a C++ library. So far, this strategy has proven successful, as only minor modifications have been made
to accommodate the nearly 400 sources of data introduced to the system in the past year. The current report describes the
design of the LBT telemetry system and its source registration process.