This paper documents the methods used for the seismic design and analysis of the Thirty Meter Telescope (TMT)2. The
seismic analysis includes response spectrum and nonlinear time history methods. Several seismic restraint design options
are considered, both linear and nonlinear, and the seismic performance is presented for these options. The paper
addresses several issues specific to large optical telescope seismic design and analysis: generation of appropriate
response spectra and time histories; use of operational and survival level earthquakes; selection of damping coefficients;
use of reduced degree of freedom models and their calibration with more detailed models; and local response spectra for
The Thirty Meter Telescope (TMT) project has revised the reference optical configuration from an Aplanatic Gregorian
to a Ritchey-Chrétien design. This paper describes the revised telescope structural design and outlines the design
methodology for achieving the dynamic performance requirements derived from the image jitter error budget. The usage
of transfer function tools which incorporate the telescope structure system dynamic characteristics and the control
system properties is described along with the optimization process for the integrated system. Progress on the structural
design for seismic considerations is presented. Moreover, mechanical design progress on the mount control system
hardware such as the hydrostatic bearings and drive motors, cable wraps and safety system hardware such as brakes and
absorbers are also presented.
The Thirty Meter Telescope (TMT) project has chosen a reference configuration with the telescope elevation axis above the primary mirror. The TMT telescope design has a segmented primary mirror, with 738 segments, nominally 1.2 m across corners, and it uses an articulated tertiary mirror to feed science light to predefined instrument positions on two large Nasmyth platforms. This paper outlines the development of the telescope structural design to meet the motion requirements related to the image quality error budget. The usage of opto-structural performance evaluation tools such as Merit Function Routine are described in addition with the optimization techniques used during the telescope structure design development.