Sample analysis plot of DMcalc using the observation of PSR J2145−0750 at BAND3 on 24 February 2019, when an excess DM was seen towards this pulsar (see Sect. 4 for the discussion). Details of the fit can be found at the top of the plot. Right panel: the top plot shows the pre-fit residuals obtained from TEMPO2 as grey circles and the Huber Regression fit to it as a dashed line in red. Middle panel: pre-fit ToAs after removing the outliers. Bottom panel: ToAs after fitting for DM using TEMPO2. The details of the analysis method can be found in Sect. 3.2. Left panel: the top panel shows an image of the frequency spectra of the pulse profiles of a 25 min observation after applying the DM correction and the bottom shows the frequency and time averaged profile of the observation. Source: PSR J2145−0750; MJD: 58538.2306; Prefit Wrms: 17.71 μs; Postfit Wrms: 6.35 μs; Median ToA Err: 7.31 μs; DM: 9.010648 ± 0.000578 pc cm⁻³; Reduced χ²: 0.50.