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Non-local effect is an important issue for a pulse-coded Brillouin optical time domain analyzer. Segmental frequency modulated probe, with a dedicated frequency step of half the natural Brillouin linewidth of the sensing fiber, is proposed to solve this issue. It can provide a wideband Brillouin gain as well as loss in the frequency band of the pump to alleviate pump distortions and thus non-local effects. This method can narrow the bit interval towards a level limited by the time of the Brillouin gain transition due to frequency switching, resulting in a bit interval as short as 900 ns for a 225 MHz frequency scanning range. A hot spot at the far fiber end is successfully detected even the probe power reaches −3 dBm under a cumulated Brillouin gain of 267.4%.