Complex sentence: Also, since the emission is a narrow spectral line, line-of-sight velocity can be determined from the Doppler shift variation of the observed frequency of the maser, permitting a three-dimensional mapping of the dynamics of the maser environment.
Split into simpler sentences: Also, since the emission is a narrow spectral line, line-of-sight velocity can be determined from the Doppler shift of the maser. This permits a three-dimensional mapping of the dynamics of the maser environment.