Passive imaging of wind surface flow using an infrared camera

We present a method for passive imaging of wind motion against surfaces in a scene using an infrared video camera. Because the method does not require the introduction of contrast agents for visualization, it is possible to obtain real-time surface flow measurements across large areas and in natural outdoor conditions, without prior preparation of surfaces. We show that this method can be used not just for obtaining single snapshot images but also for real-time flow video, and demonstrate that it is possible to measure under a wide range of conditions.