Illustration of the pulsar signal from a binary pulsar to timing data products. The binary motion of the pulsar around the binary barycentre (BB) causes Doppler shift of pulsar spin frequency. The pulsar signal propagates through ionised interstellar medium and suffers dispersive delay, causing the low-frequency signal to be delayed more than the signal at higher frequency. The plot on the right demonstrates this effect for PSR J0737–3039A observed at the L band of the MeerKAT telescope (Hu 2023). The received signal is further transferred to the Solar System Barycentre (SSB), where the Doppler shift of Earth’s motion has to be corrected.