Overview of the Progression of NASA’s CLARREO Mission

The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission enables highly accurate decadal change observations that can be tested for systematic errors on-orbit and traced to international (SI) standards. The foundation of CLARREO is the ability to produce these highly accurate measurements that will be used to detect long-term climate change trends. The mission will provide the first orbiting radiometers with accuracy sufficient to serve as reference calibration standards for other space sensors, essentially serving as a “NIST in orbit".

The CLARREO Project demonstrated readiness to begin Phase A at a fully successful Mission Concept Review in November 2010. Due to NASA budget considerations, CLARREO remains in an extended pre-Phase A with a launch readiness date of no earlier than 2023. NASA continues to fund efforts to refine the mission design and to examine alternative platforms, such as the International Space Station (ISS), focusing on lower cost implementation while achieving a majority of the CLARREO science objectives. The focus of this presentation will be on progress made since 2010, focusing on smaller, more compact instrument designs and mission architectures. In addition, the presentation will focus on the considerable progress made by the formal Science Definition Team (selected in 2010 and concluding in 2014) in advancing the rigor of climate Observing System Simulation Experiments (OSSEs), comparing CLARREO-like datasets with climate models, defining the complementary applications of CLARREO IR, RS, and GNSS-RO observations for climate signal benchmarking, and advancing the procedures for reference intercalibration.