What is the difference between intensity and reflectivity?

ouster-lidar / ouster-sdk

Ouster, Inc. sample code

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What is the difference between intensity and reflectivity? #412

Closed ywfwyht closed 2 years ago

ywfwyht commented 2 years ago

hi，guys.

What is the difference between intensity and reflectivity? Can they be interconverted?

Samahu commented 2 years ago

From our guide:

Signal Photons [16 bit unsigned int] - signal intensity photons in the signal return measurement.
Reflectivity [16 bit unsigned int] - sensor Signal Photons measurements are scaled based on measured range and sensor sensitivity at that range, providing an indication of target reflectivity.

Thus, the reported Reflectivity is a by-product of range and signal intensity that gives the user an indication of the target reflectivity.

ywfwyht commented 2 years ago

@Samahu Thank you for your reply, So intensity and reflectivity can be reciprocal? What is the transformation relation？ Is this sqrt(x^2+y^2+z^2) * intensity ?

Samahu commented 2 years ago

The relation is shown by the following equation but it is merely an approximation: $$reflectivity = α intensity range^2$$ Where $α$ is a constant

ywfwyht commented 2 years ago

OK! Thank you very much.