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Precision Timing & Quantum Sensors
Indigenous Rubidium Atomic Frequency Standard (RAFS)
Ultra-Precise Atomic Timing for Satellite Navigation
The indigenous Rubidium Atomic Frequency Standard (RAFS) developed by ISRO's Space Applications Centre (SAC) provides nanosecond-level timekeeping onboard NavIC satellites. Atomic clocks calculate precise time delay signals to measure distance between satellites and ground receivers.
Development History & Milestones
Early IRNSS satellites imported European atomic clocks which experienced in-orbit drift issues. SAC Ahmedabad and SCL Chandigarh developed an indigenous Rubidium atomic clock. The first space-qualified RAFS was deployed on NVS-01 in May 2023.
Core Space Applications
- 1NavIC NVS-series navigation satellites
- 2Deep Space Network (DSN) ground tracking stations
- 3Quantum key distribution & synchronization
Frequently Asked Questions
Why are atomic clocks necessary for satellite navigation?
Navigation systems determine location by measuring signal travel time at the speed of light. A error of 1 microsecond results in a 300-meter position error.
Technical Specifications
Frequency Stability1 × 10⁻¹³ over 1 day
Time Drift< 1 nanosecond per day
Technology TypeOptically pumped Rubidium gas cell
Lead LabSAC Ahmedabad & ISRO Telemetry Centre