Hydrometeors are not necessarily symmetrical about horizontal and vertical planes. The two polarized signals from a dual-polarized radar will encounter different amounts of water mass and return different signals. From those differences, inferences about the hydrometeor's properties can be inferred.

These differences can be divided into two categories and associated products:

1. Reflectivity differences

   • Reflectivity - both Z_h and Z_v
   • Differential Reflectivity - Z_DR
   • Correlation Coefficient - ρ_HV
2. Phase-shift differences
   • Differential Phase - φ_DP
   • Specific Differential Phase - K_DP