Configuring the Ground Station Modem

StellarStation collects modem configuration changes from authorized users, processes it, and provides it to the ground station.

These configurations include enabling carrier, changing modulation, enabling idle patterns, performing carrier sweep, changing the bitrate, etc.

(API) Near Real-time Streaming of Ground Station Modem Configuration Changes

This is done using the GroundStationConfigurationRequest.

Disclaimers:

1. Default initial configurations may vary between ground stations
2. Supported modem configuration requests vary between ground stations
3. Configuration changes only take effect for the duration of the reservation

Format

If a field is not set in the request, then the corresponding configuration for that field will not be changed on the ground station side.

For example, sending a request to change the receiver bitrate will not inadvertently affect the receiver modulation.

Timing

GS modem configuration request messages should be sent between AoS and LoS. Infostellar generally recommends the last one be sent at least 10 seconds before LoS. Modem configuration changes are made immediately upon receipt and cannot be pre-set to execute at a specific time.

Control

Only the commanding stream has control of configuring the GS modem. Please reference how command streams work.

(API) Carrier Sweep

Carrier sweep is generally used to correct for Doppler-shift and “guide” the satellite to the correct frequency. The satellite operator can command the GS modem to start sweeping the carrier up and down the frequency.

Example operation:

1. The operator requests sweep ON
2. The operator lets the sweep proceed until the satellite indicates in downlinked telemetry that the satellite is locked with the uplink
3. The operator turns sweep OFF