Optical Tolerance Analysis of the Multi-Beam Limb Viewing Instrument STEAMR
Journal article, 2014

We report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to reflector misalignment and primary reflector surface deforma-tions. Simulations were performed concurrently with the man-ufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte-Carlo simulations show that the inserts used for reflector mounting should be positioned with an overall accuracy better than 100 µm (~1/10 wavelength). Analyses of primary reflector surface deformations show that a deviation of magnitude 100 µm can be tolerable before deployment, whereas the corresponding variations should be less than 30 µm during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the reflectors in the demonstrator show that alignment better than 50 µm could be obtained.



submillimeter wave instruments

limb viewing



tolerance analysis


Arvid Hammar

Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory

Mark Whale

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Per Forsberg

Omnisys Instruments

Axel Murk

University of Bern

Anders Emrich

GigaHertz Centre

Jan Stake

Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory

IEEE Transactions on Terahertz Science and Technology

2156-342X (ISSN) 21563446 (eISSN)

Vol. 4 6 714-721 6923496

Areas of Advance

Information and Communication Technology


Kollberg Laboratory

Driving Forces

Sustainable development

Subject Categories

Remote Sensing

Other Engineering and Technologies

Other Environmental Engineering

Electrical Engineering, Electronic Engineering, Information Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering



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