We employed 0th-order (𝑳 as the identity matrix), first-, second-, and third-order differentiation matrices to recover the DRT from (2) (𝑝 = 𝑞 = 1). Table summarizes the average 𝜀 𝛾 and 𝜀 𝜕𝛾 values for each impedance model and differentiation matrix. For all DRTs except the piecewiseconstant DRT, the 1-1 pair achieved the best accuracy with 𝑳 2 or 𝑳 3 . These higher-order differentiation matrices promote regularity in the recovered DRT.