Photocurrent pulse shape on the photodetector output depends on objects surface geometry when exposing laser pulse duration is smaller then the time of radiation propagation along objects surface:

,

where  – registered radiation intensity,  – photodetector pulse response,  – aspect ratio,  – laser radiation pulse envelope,  – radiation track impulse response function,  – objects pulse scattering signature.

When , ,  parameters is known, photocurrent pulse amplitude and time characteristics can be used for object surface dimensioning in pointing direction. Therefore or corresponding voltage pulse

,

on the photodetector system output with pulse response often named as long-range object portrait.

In account of a lot of factors, which affect range images, the most effective path of its detecting is computational modeling. We made bundled software which provides long-range portraits modeling for objects with arbitrary surface shape and different scattering signature of its parts in different location conditions.Range images drawing can be counted for different types of laser radiation sources with arbitrary positions of directional radiation pattern centers, different atmospheric propagation conditions and photodetector systems parameters. Adequacy of range images modeling confirmed by achieved experimental results.

 Arbitrary surface shape objects range images modeling bundled software flowchart 

Experimentally counted (black) and counted (red)
range images of cone with diffusing surface