Portable goniospectrometer with constant observation centre

A transportable goniospectrometer with a constant observation centre for the radiometric measurement of the reflexion behaviour of a natural surface, the goniospectrometer comprising:

• a spectrometer having an optical unit and a sensor, the optical unit being connected to the sensor via an optical fibre;
• a main pillar having a lower and an upper pillar end, the main pillar including a support with respect to the natural surface;
• an arc having a fixed and a free arc end;
• a slide disposed displaceably and fixably along the arc, the slide carrying the optical unit orientated towards the observation centre;
• and
• a cantilever having a fixed and a free cantilever end, the fixed cantilever end being connected to the upper pillar end of the main pillar via a screw connection, the free cantilever end having a suspension that is rotatable and fixable about a vertical axis aligned perpendicularly to the natural surface, the suspension being connected to the sensor of the spectrometer and to the fixed arc end of the arc, the suspension being configured to position the arc at a distance of the arc radius of the arc above the natural surface.