Gold Level L2 Peak Electron Density

The GOLD night disk scan (NI1) measurements are used to derive the peak electron density (NMAX, electrons/cm3) on the disk. GOLD performs NI1 scans in both hemispheres from 17:00 to 21:00 hours spacecraft local time each night. NMAX is retrieved on a 2D rectangular (latitude vs. longitude) grid of fixed dimensions for each scan. However, the actual latitude and longitude values in the grid vary from scan to scan as the NI1 sequence utilizes a pattern of short (15 minute) localized scans that progress from east to west across the disk throughout the sequence.