Key Points Causes attenuation in RF propagation Depends on frequency and atmospheric composition Relevant in satellite and microwave links Can reduce link margin and coverage Frequency-dependent absorption peaks (oxygen and water vapor) Increases with path length and atmospheric density Distinct…
Key Points Measures rotation or angular rate Used in inertial sensing and control Supports stabilization and navigation Constraints include bias drift, noise, and temperature sensitivity Requires sensor fusion with other sensors for long-term accuracy Definition Gyroscope is a sensor that…
Key Points Supports precise pointing control Transfers angular momentum without propellant Common in spacecraft attitude control systems Works by exchanging angular momentum between the wheel and spacecraft body Enables stable pointing for antennas, sensors, and payloads Definition Reaction Wheel is…
Key Points Maintains orbital position and geometry over time Uses scheduled or on-demand maneuvers to counter drift and perturbations Relies on periodic corrections and control planning Essential for preserving satellite service continuity and mission effectiveness Constrained by propellant budget, maneuver…
Key Points Raises signal power for transmission Feeds antennas or output paths Common in RF transmitters Must balance output power, linearity, and efficiency Constraints include thermal dissipation, spectral regrowth, and power supply stability Definition Power Amplifier is an amplifier that…
Key Points Connects end users to the service network Used in satellite and access architectures Often paired with a forward or return direction Important in terminal and link planning Definition User Link is the communication path between a user terminal…
Key Points Approximately fixed over one longitude Used for communications, broadcasting, weather, and observation services Provides wide regional coverage with simple user pointing Has higher latency than lower orbits Requires station-keeping maneuvers to maintain position Benefits from stable, continuous viewing…
Key Points Provides position over time Used for satellite tracking and planning Important in navigation and mission operations Based on orbital calculations or measurements Necessary for pointing, handoff, and orbital coordination Includes orbital measurements, models, and predictions Supports communications, Earth…
Key Points Uses passive or minimal processing relay mechanism Common in traditional satellite links and broadcast systems Depends heavily on ground segment for signal processing Contrasts with regenerative payload designs Reduces spacecraft complexity at the cost of onboard flexibility Amplifies…
Key Points Lower microwave band with strong propagation characteristics Known for weather resilience compared to higher microwave bands Used in satellite communications, broadcasting, and fixed wireless systems Moderate bandwidth capacity with robust coverage Often selected where stability and reliability are…
