Absolute time encoding for temporal super-resolution using de Bruijn coded exposures

Abstract

Many target tracking tasks require high spatial and temporal precision. High frame rate imaging at high spatial resolution is commonly used in these applications, but this approach is expensive and generates large amounts of data which can complicate implementation. When tracking a single object in motion, almost all of this information is unused. A technique has been developed to exploit this sparsity and track motion with a long exposure where absolute timing is encoded by modulating the exposure over time according to a de Bruijn sequence. This technique has been implemented in the Desert Fireball Network to track bright meteors entering the Earth’s atmosphere for orbit determination and successful meteorite recovery. An alternate proof of concept implementation was also developed demonstrating tracking at 36 megapixels and 1000 Hz using a consumer camera with an inexpensive modulated light source and retroreflective target. The technique could be applied to other tracking problems requiring high temporal and spatial precision such as particle image velocimetry and space surveillance and tracking.