Radars capable of measuring targets' Polarimetrie characteristics provide valuable supplementary information for a more reliable detection, identification and physical parameters estimation. The novelty of this work lies in that it had not been previously possible to perform measurements for a comparison of polarimetric orthogonal simultaneous vs time-multiplexed sequential sounding signals in real-time, because of the time delay required to reconfigure a system to cater for the different waveform types. During this time delay, an observed non-stable target(s) would have had substantially moved, yielding both measurements not directly comparable. In this paper we present the polarimetric interleaved simultaneous-time-multiplexed waveform, justifications for the PARSAX radar setup upgrade, and the system implementation with a focus on the receiver FPGA. Preliminary results from the comparison are revealed. The data and results will be used for a future detailed comparative analysis of sounding waveforms and their impact on polarimetric target characteristics.