Fig. 2
From: High-energy electron experiments (HEP) aboard the ERG (Arase) satellite
a HEP mounted on ERG satellite and b instruments’ field of view. The HEP instrument located on the + Xsc panel of the ERG satellite (not to scale). The satellite rotates around the Zsc-axis. Fields of view of six detector modules are shown as gray areas; each module has a 60° (Elevation) × 10° (Azimuth) field of view. b Fields of view of three detector modules are shown as gray areas in the YZ-plane. Each module has a field of view of 60° and is divided into five channels such that each channel covered 12°. Elevation angle (θ) is the angle between + Zsc and the electron incident direction