Constraints for a Saturn dust environment model based on in-situ data of the CDA instrument

The Cosmic Dust Analyzer (CDA) onboard Cassini characterized successfully the dust environment at Saturn from 2004 to 2017. The study of Saturn’s E ring and its interaction with the embedded moons was a major scientific goal of Cassini. After the end of the mission, the entire CDA data can be analyzed to derive the global parameters of Saturn’s E ring.

The CDA instrument measured the primary charge, speed, mass and composition of individual submicron and micron sized dust grains. The instrument was continuously collecting data of dust fluxes and apparent dust densities. Therefore the data cover radial distances between 3 and 20 Saturn radii and equatorial as well as high latitudes. However, the relative impact velocities varied with the dynamical properties of the Cassini spacecraft and with the dust particles. Small relative impact speeds lead to higher mass thresholds for impact detection such that this effect has to be considered in calculating apparent dust densities. Furthermore, the pointing profile of the instrument and the related observation geometry was highly variable. This paper describes an approach to define a dust environment model at Saturn based on the entire CDA dataset.