20OESS Optimizing Earth Observing Constellations of Satellite Sensors Using ASPEN: A Proof-of-Concept Study for Global NWP and Nowcasting Applications

The Advanced Systems Performance Evaluation tool for NOAA (ASPEN) is applied to the problem of optimizing the design of a constellation of sensors by calculating the scientific benefit, cost, and cost effectiveness of all possible combinations of sensors within a specified catalog of sensors. ASPEN is being developed as a support tool for optimizing constellations of observing systems following the methodology employed in this study. However, this study is only a demonstration of what is possible employing the current prototype version of ASPEN restricted to sensors derived from the NOAA Satellite Observing Systems Architecture (NSOSA) study and the Geostationary Extended Observations satellite system (GeoXO) program, and targeted applications restricted to either Global NWP or a suite of nowcasting applications.

Achieving optimization adopts the approach of visualizing the results as cost-benefit “efficient frontier” scatterplots and identifying the most efficient constellations—the constellations that maximize benefit for a given cost (see Figure). The optimal constellation depends strongly on the budget, the sensor costs, the applications considered and their observational requirements and priorities, and the design ensemble of possible constellations. For illustration a simple decision rule is applied to select the optimal constellation for a given budget as the most beneficial constellation within the given budget. In practice such guidance must be carefully considered in the context of neighboring constellations in the efficient frontier scatterplot.