Optical Performance of Breadboard Amon-Ra Imaging Channel Instrument for Deep Space Albedo Measurement

Abstract

The AmonRa instrument, the primary payload of the international EARTHSHINE mission, is designed for measurement of deep space albedo from L1 halo orbit. We report the optical design, tolerance analysis and the optical performance of the breadborad AmonRa imaging channel instrument optimized for the mission science requirements. In particular, an advanced wavefront feedback process control technique was used for the instrumentation process including part fabrication, system alignment and integration. The measured performances for the complete breadboard system are the RMS 0.091 wave(test wavelength: 632.8 nm) in wavefront error, the ensquared energy of 61.7%(in 14 μ m) and the MTF of 35.3%(Nyquist frequency: 35.7 mm^{-1}) at the center field. These resulting optical system performances prove that the breadboard AmonRa instrument, as built, satisfies the science requirements of the EARTHSHINE mission.

Keywords

• space payload
• optical design
• precision fabrication
• optical system test