Radiometric imaging for scanning a scene includes a radiometer for detecting radiation emitted in a predetermined spectral range from a spot of the scene and for generating a radiation signal from the detected radiation. Spot movement circuitry effects a movement of the spot, from which the radiation is detected, to various positions. Control circuitry controls the spot movement circuit to effect the movement of the spot from one position to another position so that radiation is detected at a number of spots distributed over the scene. The number is lower than the number of pattern signals of the high-density signal pattern and the radiation signals generated from the radiation detected at the number of spots form a low-density signal pattern. Processing circuitry processes the radiation signals of the low-density signal pattern and generates the high-density signal pattern by applying compressive sensing to the low-density signal pattern.