Using Simulations to Refine Weather Surveillance Radar Requirements for SENSR

The Preliminary Performance Requirements (PPR) for a Spectrum Efficient National Surveillance Radar (SENSR) were largely based on capabilities of existing systems. The high-resolution weather surveillance requirements in the PPR either match or exceed the performance of the Weather Surveillance Radar – 1988 Doppler (WSR-88D). However, by basing the high-resolution weather surveillance requirements on the performance of the WSR-88D, requirements specific to radars that use more advanced technologies (e.g. phased-array antenna) are either missing or unclear. Furthermore, some of the more stringent requirements in the PPR are likely to be significant cost drivers for SENSR. This aims of this study are to refine and justify the high-resolution weather surveillance requirements in the PPR and to propose new requirements that take into account additional capabilities of phased-array weather radars. Examples of requirements that will be studied are antenna and range sidelobe levels, azimuthal and range sampling of the radar, and sensitivity. A two-dimensional, dual-polarization, time-series weather radar simulator based on archived data will be used to simulate outputs of radar systems with different performance requirements. Scenarios that drive the performance requirements for high-resolution weather surveillance will be identified and used as inputs to the simulator to evaluate the impact of modifying these requirements. The determination of antenna and range sidelobe level requirements using cases with large reflectivity gradients will be presented. By comparing the simulated data with the input data, biases in the estimates as a result of different sidelobe requirements can be calculated to justify the existing or newly proposed requirements.