Description
Summary:A NIR camera allows a measurement of the reflectance of the snow profile wall to identify layers of snow grains with different specific surface area (SSA) with a spatial resolution of about 1 mm. The processing of the images of RGB-cameras must consider the sensitivity of the different color pixels. The setup of the reference targets, the flat surface and the diffuse illumination is important to get high-quality images. A geometrically corrected NIR-photo gives an objective measure of the snow stratigraphy and is observer independent. This efficient measurement has been adapted for use in polar night and day by blocking out external sunlight and packaging the camera and the illuminating infrared lights into a wooden box. The width and height of the inside of the box was 500 x 675 mm. A blanket was used to prevent any light seeping through. Inside the box, lambertian reflectance targets were mounted to account for any irregular light conditions. For MOSAiC, we used lights with two different wavelengths, 850 ...