The Amon-Ra instrument is the main optical payload of the proposed EARTHSHINE satellite. It consists of a visible wavelength instrument and an IR energy channel instrument to measure a global Earth albedo. We report a new sensitivity technique for efficient alignment of the visible channel instrument. Whilst the sensitivity table method has been widely used in the alignment process, the straightforward application of the method tends to produce slow process convergence because of shop floor alignment practice uncertainties. We investigated the error sources commonly associated with alignment practices and used them when estimating the Zernike polynomial coefficients. Aided with single center field wavefront error (WFE) measurements and their corresponding Zernike polynomial coefficients, the method involves the construction and use of an experimental, instead of simulated, sensitivity table to be used for alignment state estimations. A trial alignment experiment for the Amon Ra optical system was performed and the results show that 71.28 nm in rms WFE was achieved only after two alignment iterations. This tends to demonstrate its superior performance to the conventional method.

1. INTRODUCTION
 2. NEW EXPERIMENTAL SENSITIVITY METHOD
  2.1 Theoretical method
  2.2 Target optical system: Two-mirror system with high obscuration
  2.3 Simulations and experiments with experimental sensitivity table method
 3. ALIGNMENT SIMULATION AND EXPERIMENT RESULTS
 4. CONCLUDING REMARKS
 ACKNOWLEDGEMENTS
 REFERENCES

• Eunsong Oh(Korea Ocean Satellite Center, Korea Institute of Ocean Science & Technology, Space Optics Laboratory, Dept. of Astronomy, Yonsei University)
• Ki-Beom Ahn(Korea Ocean Satellite Center, Korea Institute of Ocean Science & Technology, Space Optics Laboratory, Dept. of Astronomy, Yonsei University)
• Sug-Whan Kim(Space Optics Laboratory, Dept. of Astronomy, Yonsei University) Corresponding Author