Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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Design and Performance Analysis of an Off-Axis Three-Mirror Telescope for Remote Sensing of Coastal Water

연안 원격탐사를 위한 비축 삼반사경 설계와 성능 분석

  • Oh, Eunsong (Korea Ocean Satellite Centre, Korea Institute of Ocean Science & Technology) ;
  • Kang, Hyukmo (Korea Ocean Satellite Centre, Korea Institute of Ocean Science & Technology) ;
  • Hyun, Sangwon (Center for Anlytical Instrumentation Development, Korea Basic Science Institute) ;
  • Kim, Geon-Hee (Center for Anlytical Instrumentation Development, Korea Basic Science Institute) ;
  • Park, YoungJe (Korea Ocean Satellite Centre, Korea Institute of Ocean Science & Technology) ;
  • Choi, Jong-Kuk (Korea Ocean Satellite Centre, Korea Institute of Ocean Science & Technology) ;
  • Kim, Sug-Whan (Space Optics Laboratory, Yonsei University)
  • 오은송 (한국해양과학기술원 해양위성센터) ;
  • 강혁모 (한국해양과학기술원 해양위성센터) ;
  • 현상원 (한국기초과학지원연구원 첨단장비개발사업단) ;
  • 김건희 (한국기초과학지원연구원 첨단장비개발사업단) ;
  • 박영제 (한국해양과학기술원 해양위성센터) ;
  • 최종국 (한국해양과학기술원 해양위성센터) ;
  • 김석환 (연세대학교 우주광학연구실)
  • Received : 2015.03.16
  • Accepted : 2015.05.12
  • Published : 2015.06.25
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Abstract

We report the design and performance analysis of an off-axis three-mirror telescope as the fore optics for a new hyperspectral sensor aboard a small unmanned aerial vehicle (UAV), for low-altitude coastal remote sensing. The sensor needs to have at least 4 cm of spatial resolution at an operating altitude of 500 m, $4^{\circ}$ field of view (FOV), and a signal to noise ratio (SNR) of 100 at 660 nm. For these performance requirements, the sensor's optical design has an entrance pupil diameter of 70 mm and an F-ratio of 5.0. The fore optics is a three-mirror system, including aspheric primary and secondary mirrors. The optical performance is expected to reach $1/15{\lambda}$ in RMS wavefront error and 0.75 in MTF value at 660 nm. Considering the manufacturing and assembling phase, we determined the alignment compensation due to the tertiary mirror from the sensitivity, and derived the tilt-tolerance range to be 0.17 mrad. The off-axis three-mirror telescope, which has better performance than the fore optics of other hyperspectral sensors and is fitted for a small UAV, will contribute to ocean remote-sensing research.

본 논문에서는 연안 지역 저고도 원격측정을 위한 소형 무인항공기 용 초분광센서 개발의 일환으로 비축 삼반사경 전단광학계의 설계와 성능분석 결과를 제시하였다. 이 광학계는 수 cm의 공간해상도(4cm@500m 운영고도)와 $4^{\circ}$의 시야각, 그리고 신호대 잡음비 100(@660 nm) 이상의 요구사항을 만족시키기 위하여, 70 mm의 입사동 크기와 개구수 5.0으로 설계 사양을 가지는 비구면의 주경과 부경이 포함된 비축 삼반사경 형태로 설계되었다. 본 설계의 광학성능은 $1/15{\lambda}$ 이하 RMS 파면오차 성능과 0.75이상의 MTF 성능(@660 nm)이 기대된다. 제작과 조립 단계를 고려하여 민감도 분석을 통해 3 반사경을 정렬 보상자로 선정하였으며, 경사 공차범위는 요소별로 0.17 mrad 으로 결정되었다. 이 비축 삼반사경 광학설계는 기존 초분광센서의 전단광학계에 비해 높은 광학성능을 보이고, 소형 무인항공기에 맞추어 경량화가 가능하도록 제작 기반을 설정하여, 향후 연안 원격탐사 연구에 활용될 예정이다.

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References

  1. W. A. Hovis, D. K. Clark, F. Anderson, R. W. Austin, W. H. Wilson, E. T. Baker, D. Ball, H. R. Gordon, J. L. Mueller, S. Z. El-sayed, B. Sturm, R. C. Wrigley, and C. S. Yentsch, "Nimbus-7 Coastal zone color scanner: System description and initial imagery," Science 210, 60-63 (1980). https://doi.org/10.1126/science.210.4465.60
  2. C. R. McClain, "A decade of satellite ocean color observations," Ann. Rev. Mar. Sci. 1, 5-42 (2009).
  3. J.-H. Ryu, H.-J. Han, S. Cho, Y.-J. Park, and Y.-H. Ahn, "Overview of Geostationary Ocean Color Imager (GOCI) and GOCI Data Processing System (GDPS)," Ocean Sci. J. 47, 223-233 (2012). https://doi.org/10.1007/s12601-012-0024-4
  4. J.-H. Ryu, J.-K. Choi, and Y.-K. Lee, "Potential of remote sensing in management of tidal flats: A case study of thematic mapping in the Korean tidal flats," Ocean & Coastal Management 102, 458-470 (2014). https://doi.org/10.1016/j.ocecoaman.2014.03.003
  5. G. Vane, R. O. Green, T. G. Chrien, H. T. Enmark, E. G. Ganse, and W. M. Porter, "The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)," Remote Sens. Environ. 44, 127-143 (1993). https://doi.org/10.1016/0034-4257(93)90012-M
  6. K. L. Carder, P. Reinersman, R. F. Chen, F. M. Karger, C. O. Davis, and M. Hamilton, "AVIRIS calibration and application in Coastal oceanic environments," Remote Sens. Environ. 44, 205-216 (1993). https://doi.org/10.1016/0034-4257(93)90016-Q
  7. Z. Lee, K. L. Carder, R. F. Chen, and T. G. Peacock, "Properties of the water column and bottom derived from Airborne Visible Infrared Imaging Spectrometer (AVIRIS) data," J. Geo. Res. Oceans. 106, 11639-11651 (2001). https://doi.org/10.1029/2000JC000554
  8. Z. P. Lee, B. Casey, R. Parsons, W. Goode, A. Weidemann, and R. Arnone, "Bathymetry of shallow Coastal regions derived from space-borne hyperspectral sensor," Proc. MTS/IEEE, 2160-2170 (2005)
  9. P. J. Mumby, J. R. M. Chisholm, C. D. Clark, J. D. Hedley, and J. Jaubert, "A bird's-eye view of the health of coral reefs," Nature 413, 36 (2001).
  10. C. O. Davis, J. Bowles, R. A. Leathers, D. Korwan, T. V. Downes, W. A. Snyder, W. J. Rhea, W. Chen, "Ocean PHILLS hyperspectral imager: design, characterization, and calibration," Opt. Express 10, 210-221 (2002). https://doi.org/10.1364/OE.10.000210
  11. R. L. Lucke, M. Corson, N. R. McGlothlin, S. D. Butcher, D. L. Wood, D. R. Korwan, R. R. Li, W. A. Snyder, C. O. Davis, and D. T. Chen, "Hyperspectral Imager for the Coastal Ocean: instrument description and first images," Appl. Opt. 50, 1501-1516 (2011). https://doi.org/10.1364/AO.50.001501
  12. J.-K. Choi, J.-H. Ryu, J. Eom, S.-M. Roh, and J. H. Noh, "Analysis on the sedimentary environment and microphytobenthos distribution in the Geunso bay tidal flat using remotely sensed data," J. Wetlands Res. 12, 67-78 (2010).
  13. K. Kim, J. Eom, J.-K. Choi, J.-H. Ryu, and K. Y. Kim, "Application of hydroacoustic system and Kompsat-2 image to estimate distribution of Seagrass Beds," The Sea 17, 181-188 (2012). https://doi.org/10.7850/jkso.2012.17.3.181
  14. J.-E. Min, J.-H. Ryu, J.-K. Choi, and H.-S. Park, "Coral reef habitat monitoring using high-spatial satellite imagery : A case study from Chuuk Lagoon in FSM," Ocean and Polar Res. 32, 53-61 (2010). https://doi.org/10.4217/OPR.2010.32.1.053
  15. R. Sandau, Digital Airborne Camera: Introduction and Technology (Springer, Berlin, Germany, 2009), Chapter 4.
  16. J. Fisher and W. C. Welch, "Survey and analysis of fore-optics for hyperspectral imaging systems," Proc. SPIE 6206, 62062R-1-11 (2006).
  17. J. U. Lee, "Analytic design procedure of three-mirror telescope corrected for spherical aberration, coma, astigmatism, and petzval field curvature," J. Opt. Soc. Korea 13, 184-192 (2009). https://doi.org/10.3807/JOSK.2009.13.2.184
  18. X. L. Li, M. Xu, X. D. Ren, and Y. T. Pei, "An optical design of off-axis four-mirror anastigmatic telescope for remote sensing," J. Opt. Soc. Korea 16, 243-246 (2012). https://doi.org/10.3807/JOSK.2012.16.3.243
  19. X. L. Li, M. Xu, and Y. T. Pei, "Optical design of an off-axis five-mirror-anastigmatic telescope for near infrared remote sensing," J. Opt. Soc. Korea 16, 343-348 (2012). https://doi.org/10.3807/JOSK.2012.16.4.343
  20. P. Mouroulis, R. G. Sellar, D. W. Wilson, J. J. Shea, and R. O. Green, "Optical design of a compact imaging spectrometer for planetary mineralogy," Opt. Eng. 46, 063001-1-9 (2007). https://doi.org/10.1117/1.2749499

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