Compared to other SPIDER devices

the modified spatial-encoded-arrangement for SPIDER system (MSEA-SPIDER) are more advantageous for complex pulse measurement. Using two test pulses with different complex features as examples

the affects of the bandwidths and the spectral positions of the two quasi-monochromic auxiliary pulses on the accuracy of characterization of complex pulses are studied by means of numerical simulation. The simulation results show that both the errors of phase reconstruction for these complex pulses increase with the bandwidth enlargement of the auxiliary pulses

but their degrees of error increase are quite different. The error increases less for the complex pulse with multi-high-order dispersions but smooth profiles of spectral intensity and phase

while much larger for the complex pulse with abrupt variations in its spectral intensity and phase. Especially

when one of the frequencies of the auxiliary pulses is set near each spectral position of the abrupt variations in the pulse phase

the error of phase retrieval should be significantly large. Multishearing measurement for the same complex test pulse is helpful to find and remove this kind of error to reach higher accuracy.