Dispersive delay solutions for the best in-field calibrator, J1337+5501. This is plotted in terms of differential TEC, which has units of 10⁻¹⁶ electrons m⁻². The solutions are referenced to ST001, which is the final station in the plot. The remote stations (top two rows and first station on the third row) show relatively flat dTEC solution as these have already been corrected by PREFACTOR.