Purpose
Following the same concept as diurnal orthophotography, nocturnal orthophotography consists of an aerial images mosaic with relief distortion and perspective corrections, in order to be itself registered on a diurnal orthophotograph for analysis and classification. Night aerial photography makes possible to verify the light pollution coming from the ground that could have a negative impact on the environment by distinguishing several criteria:
- location: size of the place lit, quantity of lighting installed (over-illumination)
- the type of lamp: lamps prohibited to use (mercury vapor lamp), excessive diffusion (glare)
- the shape: orientation of the light diffusion (diffusion towards the sky)
The knowledge of the luminous environment makes it possible, thanks to night orthophotography, to respond effectively to economic needs by carrying out costs dedicated to public lighting by improving the current criteria, but also to decrease its impact on biodiversity.
An example of night orthophotography on the town of Moulins, France, carried out in 2020:
