Observing auroras with dynamic vision sensors

Auroras are a faint space weather light phenomenon caused by the interaction between the solar wind and the Earth’s magnetic field. This interaction can lead to processes that increase the energy of charged particles in the magnetosphere, enabling the particles to enter the ionosphere and cause diffuse or discrete auroras. Often, the images of auroras are captured using exposure times of 1-2 seconds to collect sufficient light. However, prolonged exposure times also intensify other light sources, such as urban- or moonlight, thus, dark night conditions are preferred. Long exposure times are also incapable of capturing fast dynamics, though some studies have carried out high-speed imaging with up to 160 frames per second (160Hz). 

Instead of traditional cameras, we propose to utilise the emerging optical technology, Dynamic Vision Sensors (DVS), that possess high dynamic ranges (110 - 120 dB) and sampling rates. DVS is a biologically-inspired silicon retina that detects negative or positive brightness change on a logarithmic scale similar to human eyes. In addition, pixels can independently adjust to lighting scenarios with an adaptable brightness threshold and without a static upper limit or constant frame rate. If no change occurs, no information is registered, providing a variable data rate and low power consumption.

Here, we present the first DVS observations of auroras in 5kHz, captured in March 2023 in Tromsø, Norway. We extract and interpret information based on reconstructed brightness and event frames. Further, we derive the incoming photon flux by mimicking a photometer. In all, we show that DVS is capable of observing auroras in challenging urban- and moonlight conditions while preserving the high temporal resolution that could enable a paradigm shift for aurora monitoring.