Lidar system and method of operation

A method for environment mapping, comprising:

• at a lidar emitter, emitting a set of optical beams toward a beam director;
• at the beam director, directing each optical beam of the set outward of a sweep axis, wherein:
• the set of optical beams intersect a reference cylindrical surface at a set of points, wherein each optical beam of the set of optical beams intersects the reference cylindrical surface at a different point of the set of points;
• the reference cylindrical surface is coaxial with the sweep axis;
• and
• a plurality of points of the set of points define a linear array along an array direction, wherein the plurality of points are substantially arrayed along the array direction, wherein a reference line parallel to the sweep axis intersects the array direction at a substantially oblique angle;
• at the beam director, while directing each optical beam of the set outward of the sweep axis, sweeping each optical beam of the set about the sweep axis, wherein each optical beam of the set sweeps out a respective region of a respective right conical surface coaxial with the sweep axis;
• at a lidar receiver, receiving a plurality of reflected optical beams, each reflected optical beam originating from a reflection, off a respective object, of a different optical beam of the set of optical beams;
• and
• based on the plurality of reflected optical beams, determining, for each reflected optical beam of the plurality, a relative location of the respective object.