CODA

Coupling of Dynamics and Aurora

CODA's two specific scientific goals were to measure the magnitude and distribution of turbulent diffusion in the lower E-region of the atmosphere as a result of auroral forcing and to measure the meso-scale (10-100 km) horizontal variations in the vertical velocities of this turbulence.

SDL designed and built or reconditioned two of the six sensor systems onboard: a Plasma Frequency/DC Probe (PFP) combination to measure electron density, which was entirely SDL technology, and an Atomic Oxygen Experiment (ATOX) to measure atomic oxygen content.

The system launched in February 2002 into a decaying aurora following a moderate to strong auroral substorm. The CODA payload followed the launch of three chemical-release rockets. Instruments aboard CODA measured the dispersion of chemical plumes from those rockets to provide estimates of turbulent diffusion in the lower E-region. Data collected indicates the spatial scales over which composition changes can occur in the auroral regions and give insight into the O/N2 ratios measured by the Global Ultraviolet Imager (GUVI) on the TIMED spacecraft.