The invention relates to vehicle sensor health monitoring. A processor of a road-side station may receive first data from a vehicle 310 and receive second data from sensors associated with the road-side station 320. The processor compares the first data and the second data 330. In response to a result of the comparing indicating a difference between the first data and the second data, the processor generates a report 340, diagnosing the health of the sensors. This may indicate inaccuracy or anomalies present in the sensors. The data may relate to positioning, weather, error detection etc. The report has a health score which may be broadcast to other vehicles or a remote location 350, 360. Health reports from other vehicle may be received 370. The data may be transmitted wirelessly using V2X communication. This allows malfunction in the sensors of an autonomous vehicle to be detected.