The Airborne Phased Array Radar (APAR) Observing Simulation, Processing, and Research Environment (AOSPRE)

The National Science Foundation (NSF) of the United States approved the Airborne Phased Array Radar (APAR) Mid-scale Research Infrastructure-2 proposal in 2023 to develop the next generation airborne polarimetric, Doppler weather radar mounted on the NSF/National Center for Atmospheric Research (NCAR) C-130 aircraft. Development of anew observing system is critical for the advancement of scientific understanding of weather phenomena. These instruments establish a proving ground for future operational transition while also providing tools for the research community. One of the issues with developing new instrumentation is the unknown performance characteristics of the instrument and the subsequent unknowns in uncertainty in measurements.

 

The APAR Observing Simulation, Processing, and Research Environment (AOSPRE) was developed to simulate APAR's measurement capabilities for heavy precipitation and high-impact weather events. Using Cloud Model 1 (CM1) and Weather Research and Forecasting (WRF) model output to provide various storms of interest and their surrounding environments, simulated NCAR C-130 flights are operated within the model space. Radar moments and dual-Pol variables are determined using the Cloud Resolving Model Radar Simulator (CR-SIM). Three-dimensional dual-Doppler radar winds can be retrieved from the Spline Analysis at Mesoscale Utilizing Radar and Aircraft Instrumentation (SAMURAI). The output can be examined directly or passed through additional tools to analyze various aspects of the data collected during each flight.

 

AOSPRE is linked to a NSF NCAR wide INtegrating Field Observations and Research Models (INFORM) to (1) establish and support best practices and methods for comparisons between models and observations, (2) exploit, assess and quantify the impacts of integrating observations and models to improve understanding of the prediction and predictability of the Earth system, and (3) improve the design, planning, deployment strategy of field programs and instrument development. The AOSPRE will be expanded into a field program planning tools as wells as a post campaign re-analysis tool with DA capability.

 

AOSPRE is developed as an open-source software. The first version of AOSPRE software has been released to the research and operational community in the last quarter of 2024. This paper will provide an overview of the AOSPRE and report the recent development of the AOS to better simulate the characteristics of a phased array radar on a moving platform. In addition, the authors will outline how AOSPRE will be used as a component in the future APAR data analysis software system.