By using highly sensitive Andor iXon EMCCD cameras closely separated and aimed at the local magnetic zenith and custom processing, we estimate the electron precipitation characteristics causing the aurora. The cameras have a 9 degree field of view (FOV) and run at their respective maximum sustained frame rate ~50 frames/sec (fps). We thereby study the finest ground-observable auroral spatio-temporal scales and use the high-speed video to obtain the fastest possible (finest time scale) estimates of auroral precipitation.
First principles auroral physics model
To keep the kinetic physics quantitative, we have to consider wavelength-dependent extinction (attenuation) of the atmosphere. The whole-atmosphere expected UV extinction is there, along with big biteouts in IR and near IR. Zenith angle = 90 - horizon elevation angle.
Time synchronization of high-speed auroral cameras
More than just taking a series of pretty pictures, time transfer (synchronization) is a critical component of this work.
We use Jackson Labs Fury GPS Disciplines Oscillators (GPSDO) with a program I developed using National Instruments X-series ASICs for a tightly synchronized triggering and monitoring system. Even $40K cameras don’t always act the way they should.
Supporting auroral observation instruments
include the all-sky camera, spectrometer, and multi-megawatt 440 MHz incoherent scatter radar (ISR). The motivating YouTube video is here.