Nanosatellite Optical Downlink Experiment (NODE) mission has 3 "signal":downlink, beacon uplink and RF.
According to a description of the mission, the high-rate downlink and beacon uplink are optical signals.
I thought we need a wide beam of the beacon signal to detect the position of the transmitter. If a beacon is optical, does that mean it has narrow beam?
What are the alternatives for beacon signals?