Method and apparatus for intensity calibration of multi-beam lidar sensors

An apparatus for multi-beam Lidar intensity measurement calibration comprising:

• a data acquisition unit which collects a plurality of data points, each data point including position information of a moving platform and intensity information from a plurality of beams;
• a processor configured to
• segment the plurality of data points into a plurality of voxels, based on the position information associated with each data point,
• find a subset of voxels in the plurality of voxels that include a point corresponding to a certain beam in the plurality of beams and an intensity value in a predetermined neighborhood of a certain intensity value;
• estimate a probability density based on the subset of voxels;
• and
• generate a calibration map that maps the certain intensity value of the certain beam to a calibrated intensity value for the certain beam, based on the probability density and a prior density.

A non-transitory computer-readable medium storing a program that, when executed by a processor, causes the processor to perform a method of multi-beam Lidar intensity measurement calibration comprising:

• determining, by a positioning device, position information of a moving platform within a global reference frame;
• collecting a plurality of data points, each data point including the position information and intensity information from a plurality of beams;
• segmenting the plurality of data points into a plurality of voxels, based on the position information associated with each data point;
• finding a subset of voxels in the plurality of voxels that include a point corresponding to a certain beam in the plurality of beams and an intensity value in a predetermined neighborhood of a certain intensity value;
• estimating a probability density based on the subset of voxels;
• and
• generating a calibration map that maps the certain intensity value of the certain beam to a calibrated intensity value for the certain beam, based on the probability density and a prior density.

A multi-beam Lidar intensity measurement calibration system comprising:

• a positioning device which determines position information of a moving platform;
• a plurality of beams;
• a data acquisition unit which collects a plurality of data points, each data point including the position information and intensity information from the plurality of beams;
• a processor configured to
• segment the plurality of data points into a plurality of voxels, based on the position information associated with each data point,
• find a subset of voxels in the plurality of voxels that include a point corresponding to a certain beam in the plurality of beams and an intensity value in a predetermined neighborhood of a certain intensity value;
• estimate a probability density based on the subset of voxels;
• and
• generate a calibration map that maps the certain intensity value of the certain beam to a calibrated intensity value for the certain beam, based on the probability density and a prior density.