1. Flight model characterization of the wide-field off-axis telescope for the MATS satellite
- Author
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Park, Woojin, Hammar, Arvid, Pak, Soojong, Chang, Seunghyuk, Gumbel, Jörg, Megner, Linda, Christensen, Ole Martin, Rouse, Jordan, and Kim, Dae Wook
- Abstract
We present optical characterization, calibration, and performance tests of the Mesospheric Airglow/Aerosol Tomography Spectroscopy (MATS) satellite, which for the first time, to the best of our knowledge, for a satellite, applies a linear-astigmatism-free confocal off-axis reflective optical design. Mechanical tolerances of the telescope were investigated using Monte Carlo methods and single-element perturbations. The sensitivity analysis results indicate that tilt errors of the tertiary mirror and a surface RMS error of the secondary mirror mainly degrade optical performance. From the Monte Carlo simulation, the tolerance limits were calculated to ±0.5mm, ±1mm, and ±0.15^∘ for decenter, despace, and tilt, respectively. We performed characterization measurements and optical tests with the flight model of the satellite. Multi-channel relative pointing, total optical system throughput, and distortion of each channel were characterized for end-users. Optical performance was evaluated by measuring the modulation transfer function (MTF) and point spread function (PSF). The final MTF performance was 0.25 MTF at 20 lp/mm for the ultraviolet channel (304.5 nm), and 0.25–0.54 MTF at 10 lp/mm for infrared channels. The salient fact of the PSF measurement of this system is that there is no noticeable linear astigmatism detected over a wide field of view (5.67^∘×0.91^∘). All things considered, the design method showed great advantages in wide field of view observations with satellite-level optical performance. more...
- Published
- 2020