To visualize more than what is visible to the naked eye, we supply multispectral images that extend our perception of the environment. We can acquire images in several spectral bands, the classic band being the near-infrared at around λ=800 nm, which allows a more accurate characterization of vegetation than visible light.
L’Avion Jaune uses arrays of digital cameras for image acquisition in the visible and near-infrared spectral bands. The infrared cameras have been professionally modified using custom-built optical components and are capable of providing a satisfactory spectral response within the spectral range of 430–900 nm. Several dedicated filters enable us to respond to remote sensing requests, in particular for agronomy:
- Infrared filter, broad band 715 nm–900 nm
- Infrared filter, broad band, 830–900 nm
- Special passband filters just 20 nm wide
The calibration measurements of the multispectral sensors are carried out by an optics laboratory. These enable us to provide precise information about the spectral response of our sensors to customers wishing to use our images for radiometric purposes.
Why do we use near-infrared?
Near-infrared (NIR) is a portion of the electromagnetic spectrum which objects absorb to a greater or lesser degree. The amount of NIR that is reflected and thus recorded in images is an important feature of their spectral signature. Capturing this signature is especially useful when studying wet zones, bare soil and vegetation. From it, we can calculate spatial indices on water content or the photosynthesizing activity of biomass that experts are then able to interpret and use in decision-making.