Fast Plasma Experiment 2-D Ion Moments (Density, Speed, Temp) 3S/12S

Description

This data set contains 2-dimensional ion moments from the Los Alamos/Garching Fast Plasma Experiment (FPE) at a time resolution of 3 seconds (high data rate) or 12 seconds (low data rate). The parameters include the ion density, flow speed, flow azimuth (zero azimuth is antisunward, negative azimuths are for flow toward dusk, positive azimuths are for flow toward dawn), the maximum and minimum temperatures, the azimuth of temperature maximum, and spacecraft position in GSE coordinates. The moments have been calculated assuming all the ions are protons, and that they uniformly fill the acceptance aperture of the FPE. Due to instrumental limitations, the data beyond the earth's bow shock are inaccurate and should be ignored. Solar wind data obtained during multiple crossings of the bow shock have not been edited out but can usually be recognized in the data. The experiment essentially measures only background when in the empty lobes of the tail; these data have not been edited out either. However, data contaminated by energetic particles (from the Earth's radiation belts or solar events) have been edited out. Changes in the efficiency of the instrument have not always been adequately accounted for in the data processing; the uncertainty in the absolute density is believed to be about 50%, while relative changes in density on any given day should be good to about 10%. The ISEE-2 FPE failed in April 1980, and there are no useful data beyond that point.