Sensor apparatus

A portable sensor apparatus (10, Fig.1) for surveying a building comprises a sensor unit 12. It comprises a rangefinder sensor 16 and multiple outwardly directed thermal imaging sensors 20 arranged to capture sensor data associated with its environment as the sensor unit is moved through a scanning motion (e.g. rotation). The field of view of each of the thermal imaging sensors overlaps both the FoV of the rangefinder sensor and the FoV of one of the other thermal imaging sensors. The unit may also comprise cameras 24. The principal axis (64, 66, Fig.5) of each thermal imaging sensor and camera may intersect the axis of rotation (62, Fig.5)). Also disclosed is apparatus comprising a sensor unit which is moveable in a scanning motion (or configured to rotate) and comprises a rangefinder, a thermal imaging sensor and a camera. Also disclosed is apparatus comprising a rotatable sensor unit wherein a field of view of a sensor encompasses first and second portions of the axis of rotation in respective opposite directions.