Satellite ground station terminology often comes from radio engineering, spacecraft operations, and telecommunications standards. While these terms are well defined in technical documents, their real-world meaning can be unclear without operational context. Operators frequently encounter these terms during live contacts, troubleshooting, and reporting, where practical understanding matters more than formal definitions.
This glossary is written specifically for ground station operators and operational teams. Each definition explains not only what a term means, but how it is used during day-to-day operations and why it matters. The goal is to bridge the gap between theory and practice, providing clear, usable explanations that support confident decision-making.
Table of contents
- How to Use This Glossary
- RF and Signal Terms
- Link and Performance Terms
- Operations and Contact Terms
- Network and Data Terms
- Control and Command Terms
- Why Practical Definitions Matter
- Ground Station Glossary FAQ
- Glossary
How to Use This Glossary
This glossary is organized around how operators encounter concepts in real operations, rather than strict alphabetical order. Terms are grouped by functional area so that related concepts can be understood together. This reflects how operators think during a pass, troubleshooting session, or post-contact review.
Each definition is intentionally longer than a traditional glossary entry. Operators benefit from understanding context, common failure modes, and operational impact. If a term appears elsewhere on the site, this glossary provides the practical grounding needed to interpret it correctly during live operations.
RF and Signal Terms
RF (Radio Frequency) refers to the electromagnetic signals used to communicate between satellites and ground stations. In practice, RF is what operators are monitoring when watching signal levels, spectrum displays, or lock indicators. RF quality determines whether a contact is even possible.
Signal-to-Noise Ratio (SNR) describes how strong the desired signal is relative to background noise. Operators see SNR change during passes as satellites rise and set, or when weather affects the link. A dropping SNR is often the first sign of pointing issues, interference, or environmental degradation.
Noise Floor represents the baseline level of unwanted energy present in the receiver. Operators rarely control the noise floor directly, but understanding it helps interpret why a signal may not be decodable even when it appears present. Elevated noise floors can indicate interference or hardware problems.
Link and Performance Terms
G/T, or gain-to-noise-temperature ratio, is a measure of receive performance. While operators may not calculate G/T during operations, they experience its effects when weak satellites are still decodable under poor conditions. Higher G/T generally means more forgiving operations.
EIRP, or Effective Isotropic Radiated Power, describes how strong an uplink appears from the satellite’s perspective. Operators see the impact of EIRP when commands fail to be acknowledged or when uplink margins are tight. Adjustments to power levels or antenna configuration often relate directly to EIRP.
Link Margin is the operational buffer that allows communication to continue despite degradation. Operators rely on margin during bad weather, low elevation passes, or unexpected interference. Running with minimal margin increases operational stress and risk.
Operations and Contact Terms
Pass refers to the time window during which a satellite is visible to a ground station. Operators plan their activities around passes, knowing that missed time cannot be recovered. Short passes demand efficient execution and clear procedures.
Contact is a successful communication session during a pass. A contact is not simply visibility; it requires establishing a link, exchanging data, and completing planned activities. Operators often track contact success as a key performance indicator.
Acquisition of Signal (AOS) marks the moment a usable signal is first detected. Operators use AOS timing to verify predictions and antenna tracking accuracy. Delays or early AOS events can indicate orbital prediction issues.
Network and Data Terms
Baseband refers to the digitally processed signal before it is converted into IP traffic. Operators encounter baseband systems when monitoring demodulator status or data framing. Issues here often appear as corrupted or missing data.
IP (Internet Protocol) represents the point where satellite data enters standard networks. Once data is IP-based, it can be routed, stored, and processed using conventional IT tools. Operators often coordinate with network teams at this boundary.
Latency describes the delay between transmission and reception. Operators experience latency when commanding satellites or monitoring near-real-time data. Understanding expected latency prevents misinterpretation of delayed responses as failures.
Control and Command Terms
Telemetry is health and status data sent from the satellite. Operators monitor telemetry continuously during contacts to detect anomalies early. Unexpected telemetry values often trigger escalation procedures.
Command refers to instructions sent from the ground to the satellite. Operators treat commands with special care, as incorrect execution can have lasting effects. Command authorization and verification are core operational responsibilities.
TT&C combines telemetry, tracking, and command into a single operational function. Operators recognize TT&C as the highest-priority traffic, protected above payload data. Losing TT&C capability represents a serious operational event.
Why Practical Definitions Matter
Operators work under time pressure, incomplete information, and real-world constraints. In these conditions, purely academic definitions provide limited value. Understanding how terms behave during operations improves judgment and response quality.
Practical definitions also improve communication between operators, engineers, and mission teams. When everyone shares the same operational understanding, issues are diagnosed faster and resolved more effectively.
Ground Station Glossary FAQ
Why are these definitions longer than a typical glossary?
Because operators benefit from context and examples, not just formal wording.
Longer explanations support better decision-making during live operations.
Is this glossary suitable for engineers as well?
Yes. Engineers can use it to understand how technical concepts are experienced
and interpreted by operators in real-world conditions.
Will these definitions change over time?
Possibly. As systems evolve and operational practices change, practical
interpretations may be refined to stay relevant.
Glossary
RF: Radio-frequency signals used for satellite communication.
SNR: Ratio of signal strength to background noise.
Noise floor: Baseline level of unwanted receiver noise.
G/T: Measure of receive performance combining antenna gain and noise.
EIRP: Effective strength of an uplink signal.
Pass: Time window when a satellite is visible to a ground station.
Contact: Successful communication session during a pass.
Baseband: Digitally processed signal before IP conversion.
TT&C: Telemetry, Tracking, and Command.
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