Optical Ground Station

To perform satellite-to-ground optical communications, the OGS needs to track, receive, and decode the transmitted signal. Simultaneously, it must provide its own beacon at a wavelength of 1064 nm in order for the satellite to be able to track the OGS. The satellite’s Payload transmits two beacons: a 1550 nm transmission laser and a 638 nm beacon laser. This three-laser system is at the core of PULSE-A’s design.

In order for the OGS to function as a receiving terminal for polarization-based optical communications, it must satisfy the following requirements on pointing, tracking, and decoding laser transmissions:

  1. The OGS shall transmit the ground station laser beacon to the satellite.

  2. The OGS shall point to the satellite.

  3. The OGS shall track the Payload beacon laser.

  4. The OGS shall detect the downlink transmission laser’s wave packets as bits based on separated polarization states.

  5. The OGS shall decode the downlink transmission laser into digital data.

These system requirements are accomplished by four assemblies within the OGS: Tracking, Polarization State Preparation, Signal Decoding, and Beacon.

The OGS design diagram is below.

ogs diagram