A solar radiation detector comprises a shading element that casts a shadow over one of a number of sensors disposed about the shading element. The shading element and the sensors are spaced in relation to each other that the shadow cast by the shading element always falls on one of the sensors, completely shading that one sensor, while at the same time leaves at least another one of the sensor completely exposed to direct solar radiation. The completely shaded sensor measures substantially only diffuse solar radiation.