Underwater sensing system

A Light Detection And Ranging (LiDAR) system, comprising:

• a light source;
• an on-axis sensor;
• an off-axis sensor;
• a computing system coupled to at least the on-axis sensor and the off-axis sensor, the computing system comprising a processor and a memory having stored therein instructions for causing the process to perform the steps of:
• obtaining, from the off-axis sensor, off-axis power return characteristics with respect to a first wavelength of light generated by the light source;
• obtaining, from the on-axis sensor, on-axis power return characteristics for at least the first wavelength of light;
• estimating at least one beam attenuation coefficient (c) based on the off-axis power return characteristics and common volume parameter function for the LiDAR system and an extinction coefficient (α) for the medium based on the on-axis power return characteristics;
• and
• extracting a value for at least one diffuse attenuation coefficient (Kd) for the medium using a beam spread parameter for the LiDAR system (D) and a pre-defined relationship between α, c, D, and Kd.

A computer-readable medium having stored therein a computer program for causing a computing device to characterize scattering in a medium of a Light Detection And Ranging (LiDAR) system, the computer comprising a plurality of code sections for:

• obtaining off-axis power return characteristics with respect to a first wavelength of light and on-axis power return characteristics for at least the first wavelength of light;
• estimating at least one beam attenuation coefficient (c) based on the off-axis power return characteristics and common volume parameter function for the LiDAR system and an extinction coefficient (α) for the medium based on the on-axis power return characteristics;
• and
• extracting a value for at least one diffuse attenuation coefficient (Kd) for the medium using a beam spread parameter for the LiDAR system (D) and a pre-defined relationship between α, c, D, and Kd.