We report on an additional limitation that has been found in Brillouin optical time-domain analysis (BOTDA) sensors due to the so-called second-order nonlocal effects (NLE). Second-order NLE appear in BOTDA setups that deploy a double probe waves to compensate the transfer of energy between the pump pulse and the probe wave. and are related to a spectral distortion of the pump pulse t... https://www.remtavares.com/