The invention relates to a system and a method for optical measurement of a target, wherein the target is illuminated, either actively illuminated, reflecting ambient light, or self illuminating, and a measurement radiation beam received from the target or through it is detected. The measurement system has optical fibers for guiding radiation from/to target positions. Radiation of several target positions is simultaneously filtered by a Fabry-Perot interferometer and detected by a row detector, for example.