Noise reduction in light detection and ranging based imaging

An apparatus comprising:

• an interface configured to receive voxel data for each of a plurality of voxels, each voxel associated with a unique volume of space associated with a geographic area, the voxel data for each respective voxel comprising one or more values based on one or more reflections from one or more light pulses from a light detection and ranging (LIDAR) system;
• and
• a processor coupled to the interface and configured to:
• identify noise values from among the one or more values for each respective voxel;
• determine a baseline threshold comprising a static value that is uniform for each of the plurality of voxels;
• determine a dynamic threshold that varies between the plurality of voxels, the dynamic threshold based on the identified noise values, wherein the variation of the dynamic threshold between the plurality of voxels corresponds to spatial variations inherent in the LIDAR system;
• apply the baseline threshold and the dynamic threshold to the voxel data to generate filtered voxel data;
• generate a three-dimensional image based on the filtered voxel data;
• determine an along-path histogram based on noise values from among the one or more values for each respective voxel along a flight path of the LIDAR system;
• determine a cross-path histogram, the cross-path histogram based on noise values from among the one or more values for each respective voxel perpendicular to the flight path of the LIDAR system;
• and
• multiply the along-path histogram by the cross-path histogram.

Logic embodied on a tangible non-transitory computer readable medium, that when executed is configured to:

• receive voxel data for each of a plurality of voxels, each voxel associated with a unique volume of space associated with a geographic area, the voxel data for each respective voxel comprising one or more values based on one or more reflections from one or more light pulses from a light detection and ranging (LIDAR) system;
• identify noise values from among the one or more values for each respective voxel;
• determine a baseline threshold comprising a static value that is uniform for each of the plurality of voxels;
• determine a dynamic threshold that varies between the plurality of voxels, the dynamic threshold based on the identified noise values, wherein the variation of the dynamic threshold between the plurality of voxels corresponds to spatial variations inherent in the LIDAR system;
• apply the baseline threshold and the dynamic threshold to the voxel data to generate filtered voxel data;
• generate a three-dimensional image based on the filtered voxel data;
• determine an along-path histogram based on noise values from among the one or more values for each respective voxel along a flight path of the LIDAR system;
• determine a cross-path histogram, the cross-path histogram based on noise values from among the one or more values for each respective voxel perpendicular to the flight path of the LIDAR system;
• and
• multiply the along-path histogram by the cross-path histogram.