Gaofen-9 02 & HEAD-4

Gaofen (GF) is a series of Chinese civilian remote sensing satellites for the state-sponsored program China High-definition Earth Observation System (CHEOS).

HEAD-4 is a Chinese commercial satellite by HEAD Aerospace to track ships receiving their AIS (Automated Identification System) signals. The three-axis stabilized satellites are built by SAST (Shanghai Academy of Spaceflight Technology) and feature a high-performance AIS-receiver capable of processing 2 million AIS short messages and identifying 60000 ships per day. Future satellites will feature VEDS and ADS-B payloads for global ship detection and airplane monitoring services.