Design methodologies are developed for complementary frequency modulated (FM) waveforms and for optimised complementary mismatched filtering (MMF) of arbitrary non-repeating waveforms. The former is a sub-class of random FM waveforms denoted as complementary FM (Comp-FM) while the latter extends a practical instantiation of least-squares mismatched filtering yielding the mismatched complementary-on-receive filtering (MiCRFt) scheme. Both of these approaches have an emphasis on the nonideal physical effects of the radar transmitter and receiver, thereby permitting highfidelity simulation analysis and subsequent experimental demonstration of their efficacy using open-air measurements.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.