Oxygen A-band spectrometer breadboard for the orbiting carbon observatory

The Oxygen A-band spectrometer breadboard was developed to demonstrate alignment and focus methodologies planned for the spectrometers to be used for the Orbiting Carbon Observatory (OCO). The OCO is a proposed Earth System Science Pathfinder (ESSP) mission to provide the first global CO2 measurements from space with a relative accuracy of 1-ppm on scales of 2.5 x 10(5) km(2). The flight system uses three refractive spectrometers to measure column CO2 at 1.58 and 2.06-micrometers and column O-2 in the oxygen A-band at 0.76 micrometers. This paper describes a relatively fast, f/2, high resolution grating spectrometer breadboard designed, manufactured, and tested in less than 6 months. The breadboard successfully validates the optical design and alignment approach to be used for the three spectrometers that comprise the OCO instrument.