While classical configurations have a practical spatial resolution of 1 meter, novel approaches have been demonstrated that can overcome this limit to offer spatial resolutions in the centimetre range, while preserving full measurand accuracy.OCIS codes: (060.2370) Fiber optics sensors; (290.5900) Scattering, stimulated Brillouin.Optical fibre sensors based on stimulated Brillouin scattering have now clearly demonstrated their excellent capability for long-range distributed strain and temperature measurements. The fibre is used as sensing element and a value for temperature and/or strain can be obtained from any point along the fibre. While classical configurations have practically a spatial resolution limited by the phonon lifetime to 1 meter, novel approaches have been demonstrated these past years that can overcome this limit. This can be achieved either by the prior activation of the acoustic wave by a long lasting pre-pumping signal, leading to the optimized configuration using Brillouin echoes, or by probing a classically generated steady acoustic wave using a ultra-short pulse propagating in the orthogonal polarization of a highly birefringent fibre. These novel configurations can offer spatial resolutions in the centimetre range, while preserving the full accuracy on the determination of temperature and strain.The commonly accepted opinion that the spatial resolution of a pulse-based Brillouin sensor is limited to 1 m was seriously questioned when Bao et al observed an unexpected narrowing of the Brillouin gain spectrum down to its natural linewidth when pulses turned shorter than the phonon lifetime (6 ns) [1]. It is now unanimously accepted by all specialists that this special behaviour results from a pre-excitation of the acoustic wave through the presence of a continuous background pump [2]. Basically, the observation of this effect depends on the pre-existence of an important acoustic wave in the fibre medium vibrating at the exact Brillouin frequency resonance. This acoustic wave is conveniently generated through stimulated Brillouin scattering using a continuous wave at the probe frequency and another continuous wave (or a long pulse) at the pump frequency. Among the 3 waves involved in the interaction, the 2 optical waves can experience very fast changes in their amplitude and phase, while the acoustic wave presents a highly inertial behaviour and requires a typical time equal to a multiple of its 6 ns lifetime to adapt to a new situation. For instance, if the pump is suddenly turned off, the acoustic wave will gradually decay and will still exist during the typical duration of its lifetime, despite the absence of stimulated interaction. This inertial property is used to change very briefly amplitude or phase of the pump, during a time T so short that the acoustic wave does not experience a notable change (T << phonon lifetime. This way the pump will be reflected by the acoustic wave, but under transient conditions that do not correspond to those required by amplitude and phase matchin...