Studio: Ground Stations
Description
Ground stations are objects that sit on the surface of planets (typically the Earth) and can be used for communicating with spacecraft. Ground stations can have telecommunication systems (TT&C) on board and enable both uplink and downlinking of commands to the spacecraft. Nominal Studio currently does not support full-scale simulation of TT&C systems but does support access data for connections with spacecraft. This guide will demonstrate how to add ground stations to the simulation and how to check access with a spacecraft.
Adding Ground Stations
A ground station can be added to the simulation using the Inventory panel by selecting the Ground Station button. This will add a default (empty) ground station to the scene. By default, the ground station will be positioned at a latitude of 0 degrees and a longitude of 0 degrees. Depending on the time of day Nominal Studio is being run, this might be on the night side of the Earth.
To adjust the location of the ground station, select the ground station object in the Outliner panel and then head down to the Properties panel. Under the Transform tab, there will be a Geolocation section. This will enable the user to change the body it is located on and the appropriate geodetic coordinates for the ground station.
Visualization Cones
Under the ground station tab of the Properties panel, there is a Visualization section. To enable the visualization of the ground station field of view, select the checkbox in the section. The colour can be changed and cycled through a series of selected colours. The colour will change the cone colour displayed on the ground station.
The cone will display the appropriate region that is accessible from the ground station. This depends on both the Min Elevation (above the horizon of the ground station) and the Range of the ground station (from the ground station location). These properties, when changed, will affect the cone of visualization and the connection to any spacecraft that passes through overhead.
Accessing Spacecraft
When the spacecraft is within the range of the ground station, an event on the spacecraft will be triggered that will display the time that it is within the range of the ground station. Additionally, a line that points towards the ground station will be visualized on the Viewport, indicating an active connection to the ground station. This depends on the visualization cone of access to the ground station and the spacecraft’s position in orbit.
Note
For the accessing of ground station events, no TT&C or signalling components are required to be added to the ground station or the spacecraft. This will work with any generic spacecraft or ground station present in Nominal Studio.
Link Budgeting
An important factor of spacecraft simulations is to understand the length of time that a ground station pass runs for and information about the links between antennae. Nominal Studio can simulate the link budgets per spacecraft-ground station link. However, this requires an antenna to be located on both the ground station and the spacecraft. As an example, a Radion Receiver could attached to the ground station and a Radio Transmitter could be attached to the spacecraft. This would create a valid link.
Warning
For link budgeting to work, the frequencies in which both the receivers and transmitters must match exactly. The default assets are set such that the frequencies are all 6 GHz and are already configured to be the same.
When the simulation is running, under the ground station tab of the Properties panel, a link will be shown between the spacecraft and the ground station. It will include information about whether it is connected, the distance to the ground station, the signal-to-noise in decibels and the total length of time that the pass has gone for. This will only be displayed while the simulation is running.
