Poster + Presentation + Paper
20 September 2020 Tolerance analysis of wide field of view confocal off-axis telescope system using freeform mirrors for common optics MWIR/LWIR sensors onboard UAVs: linear astigmatism free three mirror system D70F1.4
Author Affiliations +
Conference Poster
Abstract
Linear Astigmatism Free - Three Mirror System (LAF-TMS) is a confocal off-axis system that eliminates linear astigmatism, which is the most critical aberration especially in the large field angle, and therefore, enables the telescope to have a wide field of view. Based on our experience with the telescope, we optimized the LAF-TMS for wavelength ranges of mid-wavelength infrared (3-5 µm) and long-wavelength infrared (8-12 µm) sensors onboard Unmanned Aerial Vehicles (UAVs). It has an entrance pupil diameter of 70 mm, a focal ratio of 1.4, and a wide field of view (FoV) of 6.20° × 4.68°, matching 10.9 mm × 8.2 mm sensor with 17 µ m sized pixels (LAF-TMS D70F1.4). The freeform mirrors of LAF- TMS D70F1.4 are optimized to eliminate the high order aberration. As a result, LAF-TMS D70F1.4 can achieve high- quality optical performance over a wide FoV without any additional correcting lenses. We performed the sensitivity analysis and the Monte-Carlo simulations as the feasibility study. During the sensitivity analysis and the Monte-Carlo simulation, decenter, tilt, despace, and surface RMS errors of three mirrors were analyzed. From the sensitivity analysis, we investigated 80% Energy Encircled Diameter by single factor perturbations. The system tolerance limits were calculated using the Monte-Carlo method with a normal distribution of errors. According to the results, we confirmed that the LAF-TMS D70F1.4 was feasible considering general fabrication and alignment tolerances.
Conference Presentation
© (2020) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jimin Han, Woojin Park, Seunghyuk Chang, Sunwoo Lee, Hojae Ahn, Dae Wook Kim, Geon Hee Kim, Dae-Hee Lee, Hanshin Lee, and Soojong Pak "Tolerance analysis of wide field of view confocal off-axis telescope system using freeform mirrors for common optics MWIR/LWIR sensors onboard UAVs: linear astigmatism free three mirror system D70F1.4", Proc. SPIE 11537, Electro-Optical and Infrared Systems: Technology and Applications XVII, 115370R (20 September 2020); https://doi.org/10.1117/12.2573698
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KEYWORDS
Mirrors

Tolerancing

Off axis mirrors

Telescopes

Monochromatic aberrations

Confocal microscopy

Sensors

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