NavIC Navigation System | 17 Mar 2026

Source: IE  

Why in News?  

The Indian Space Research Organisation (ISRO) announced that the atomic clock onboard the Indian Regional Navigation Satellite System (IRNSS)-1F satellite of India’s regional navigation system stopped functioning. 

• This comes amid other technical setbacks in India’s navigation constellation, including the NVS-02 satellite’s failure to reach its final orbit, raising concerns about the reliability of NavIC (Navigation with Indian Constellation). 

What is IRNSS or NavIC? 

• About: The Indian Regional Navigation Satellite System (IRNSS), operationally known as Navigation with Indian Constellation (NavIC), is India's indigenous satellite navigation system. 
  • It was designed to provide accurate positioning information to users in India and up to 1500 km beyond its borders, which constitutes the Primary Service Area.  
  • In addition, an Extended Service Area covers the region between the primary area and the rectangle bounded by 30° South to 50° North latitude and 30° East to 130° East longitude. 
• Need for NavIC: The project was initiated to ensure strategic autonomy in navigation services. 
  • During the 1999 Kargil conflict, the US denied India access to GPS data, highlighting the risks of relying on foreign systems. To address this vulnerability, India approved the NavIC project in 2006. 
• NavIC Services:  
  • Standard Positioning Service (SPS) is available to all civilian users and offers positioning information for general navigation purposes.  
  • Restricted Service (RS) is an encrypted service available only to authorised users, primarily for strategic and defence applications.  
    • The system is designed to deliver position accuracy better than 20 metres within the primary service area. 
• Key Features: NavIC’s Standard Positioning Service provides accuracy of about 5–10 metres across India. 
  • Accuracy around 20 metres is expected in regions up to 1,500 km beyond India. 
  • Unlike GPS, NavIC uses dual frequencies (L and S bands), allowing better correction of atmospheric errors and potentially higher accuracy.  
    • Works better than global systems in difficult terrains such as valleys, forests, and urban areas where GPS signals may weaken. 
• Applications of NavIC: Supports terrestrial, aerial, and marine navigation, disaster management, and vehicle tracking and fleet management. 
  • Enables integration with mobile phones and smart devices, provides precise timing services, and supports mapping, geodetic data collection, and navigation assistance for drivers, hikers, and travellers. 
• NavIC Satellite Constellation Performance:  The NavIC constellation has been built through a series of satellite launches using the Polar Satellite Launch Vehicle (PSLV).  
  • First Generation (IRNSS Series): The first generation of NavIC satellites includes the IRNSS-1 series, launched between 2013 and 2018. 
    • Key satellites include IRNSS-1A, 1B, 1C, 1D, 1E, 1F, 1G, and the replacement satellite IRNSS-1I. 
    • IRNSS-1H (2017), intended to replace IRNSS-1A, failed to reach orbit due to heat shield separation failure. 
    • The IRNSS-1I was launched in 2018 as a replacement after the 2017 IRNSS-1H mission failed. 
    • Several satellites in this series have experienced atomic clock failures or are nearing the end of their mission life, affecting navigation services. 
  • Second Generation (NVS Series): The NVS series represents the second generation of NavIC satellites, developed to improve reliability and expand capabilities. 
    • It includes NVS-01, NVS-02, and the planned  (NVS-03, NVS-04, and NVS-05). 
    • NVS-01 (2023) is operational and hosts an indigenously developed rubidium (atomic) clock and L1 band signals. 
    • NVS-02 (2025) faced issues in reaching its final operational orbit due to an onboard technical problem. 
    • The newer satellites boast a mission life of 12 years, an upgrade from the 10-year lifespan of the previous generation. 
    • In addition to the L5 and S frequency signals, the new satellites transmit in a third frequency, L1. 
      • The L1 frequency improves interoperability with other global positioning systems like GPS and allows NavIC data to be used in low-power wearable devices, such as smartwatches. 
  • Active Satellites: Following the loss of the IRNSS-1F's atomic clock, only four satellites are currently capable of providing positioning data: IRNSS-1B, 1C, 1I, and the new-generation NVS-01. 
• Technological Developments in NavIC: 
  • Indigenous Atomic Clocks: ISRO developed Indian rubidium atomic clocks to reduce dependence on imported frequency standards.  These clocks will power the next generation of satellites (NVS series). 
  • NavIC-Compatible Chips: Qualcomm chipsets began supporting NavIC signals in 2020. 
    • Future devices will support L1 band signals, improving compatibility with smartphones and IoT devices. 
  • Indigenous Microprocessor: The AJIT microprocessor (the first ever microprocessor to be conceptualised, designed, developed and manufactured in India), developed by IIT Bombay, is planned for integration into NavIC receivers. 
• Policy and Regulatory Developments: NavIC-based vehicle tracking systems became mandatory for commercial vehicles in India in 2019. 
  • In 2019, the US recognised NavIC as an allied navigation system under the National Defense Authorization Act, 2020. 
  • NavIC will also serve as the reference time provider for India’s National Physical Laboratory from 2025.

What is an Atomic Clock? 

• About: An atomic clock is an extremely precise timekeeping device that measures time using the natural vibration frequency of atoms (frequency is essentially the inverse of time).  
  • Unlike ordinary clocks that rely on mechanical movement or quartz crystals, atomic clocks use the stable energy transitions of atoms, making them the most accurate clocks ever created. 
• Working Principle: Atomic clocks work by measuring the specific frequency of microwaves required to cause electrons in an atom to change energy levels. 
  • This frequency is constant for each type of atom and acts as a natural reference for measuring time. 
• Accuracy: Atomic clocks are extraordinarily accurate and stable. Some advanced atomic clocks may lose or gain less than a second over millions of years, making them ideal for applications requiring extremely precise timing. 
• Use in Navigation: Atomic clocks are widely used in satellite navigation systems such as GPS and NavIC, where they measure the exact time taken by signals to travel between satellites and receivers to determine precise location. 
• Importance: Highly precise atomic clocks also help track spacecraft, calculate trajectories, and enable autonomous navigation for deep-space missions.