Performance Evaluation of Spaceborne Conically Scanning Radar in Measuring Wide-Area Three-Dimensional Cloud Structures

The newly developed spaceborne conically scanning radar represents the first satellite system capable of integrating wide-area Doppler wind measurement with three-dimensional (3D) observations of cloud structures. This study aims to analyze and evaluate the performance of spaceborne conically scanning radar in capturing wide-area 3D cloud structures. To assess the impact of observation geometric parameters on cloud structures, theoretical analyses were first conducted to examine the influence of key parameters including incidence angle, antenna spin rate and along-conic resolution. The results indicate that a set of 41.6°, 12 rpm and 5 km achieve high-density sampling across an 800 km swath, with sensitivity better than −31 dBZ. To verify its capability in resolving the 3D structure of mesoscale weather systems, WRF model numerical simulations were performed for typical weather cases. Thanks to its swath and high sampling density, the simulations captured the complete 3D features of these systems, demonstrating strong continuity in both horizontal and vertical reflectivity structures. Furthermore, the 12 rpm set shows superior performance compared to 8.6 and 10.7 rpm sets due to its higher horizontal resolution. Given the non-uniform sampling of conical scanning, the original conic-scanning simulation results were reconstructed into a 3D-grid format for further practical applications. The results demonstrate that a grid resolution of 0.1° × 0.2° effectively reconstructs the 3D structure for the 12 rpm set, which shows good consistency with the simulated echoes of high-resolution WRF scenes (resolution of 3 km × 3 km), with a correlation up to 0.94 and an RMSE less than 3 dBZ. This study aims to provide technical support for the design and optimization of China’s spaceborne cloud radar.