QUANTUM NAVIGATION

Source: THEPRINT

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Context

• In May, the UK carried out two separate quantum navigation tests – one aboard a Royal Navy ship and another on a small jet plane.
• The following month, London’s underground transport system became a testing site for the technology.
• The tests successfully demonstrated that quantum navigation is ‘unjammable’, and the UK’s research is paving the way for the technology to be rolled out more widely in the future.

Details

Quantum Navigation

• Quantum navigation is an emerging technology that leverages quantum mechanics to provide precise location and navigation information.
• Unlike traditional GPS, which relies on satellite signals, quantum navigation focuses on the behavior of atoms under cryogenic conditions.
• This technology promises greater resilience against common GPS vulnerabilities such as signal jamming and spoofing.

Fundamentals of Quantum Navigation

• Core Principle:Quantum navigation uses the quantum properties of atoms to measure movement and position with extreme precision.
• Cryogenic Conditions:Atoms are cooled to near absolute zero to minimize thermal noise and enhance measurement accuracy.
• Measurement:The movement of a single atom or a group of atoms is tracked to determine location and velocity. These measurements are highly stable and less prone to drift.

How Quantum Navigation Works

• Quantum Sensors:Quantum navigation systems use highly sensitive quantum sensors that measure changes in atomic states.
• Atomic Interferometry:This technique involves splitting and recombining atomic wavefunctions to measure phase shifts caused by movement, providing precise positional data.
• Self-Contained:Unlike GPS, quantum navigation systems are self-contained and do not rely on external signals, making them immune to external disruptions.

Advantages of Quantum Navigation

• Unjammable:Since quantum navigation does not rely on external signals, it is not susceptible to jamming or spoofing.
• High Precision:Offers extremely high accuracy in location tracking, potentially surpassing the precision of GPS.
• Independence:Operates independently of satellites, providing reliable navigation in environments where GPS is unavailable or unreliable, such as underwater or in dense urban areas.

Applications of Quantum Navigation

• Military:Ensures reliable navigation for military operations in contested environments where GPS may be compromised.
• Aviation:Provides precise navigation for aircraft, enhancing safety and reliability, particularly in GNSS-denied areas.
• Maritime:Essential for underwater navigation where GPS signals cannot penetrate.
• Urban Navigation:Offers robust navigation solutions in urban canyons where GPS signals are often weak or blocked.

Challenges

• Size and Complexity:Current quantum navigation systems are bulky and complex, requiring significant miniaturization for widespread adoption.
• Cryogenic Requirements:The need for ultra-cold conditions makes the technology challenging to implement in standard environments.
• Cost:High development and operational costs may limit initial deployment to specialized applications.

Comparison with GPS

Aspect	GPS	Quantum Navigation
Signal Source	Satellites	Atomic measurements
Susceptibility to Jamming	High	Low
Susceptibility to Spoofing	High	Low
Precision	High (within a few meters)	Potentially higher (sub-meter accuracy)
Dependency	External satellite signals	Self-contained, no external signals
Operational Environments	Limited in GNSS-denied areas	Effective in all environments, including underwater
Development Stage	Mature, widely available	Emerging, experimental

Navigation Systems

• Navigation systems are crucial for determining the position, velocity, and trajectory of objects or individuals.
• They are used in various applications, from personal vehicle navigation to military operations and space exploration.

Working Principles of Navigation Systems

• Triangulation:Many navigation systems, especially satellite-based ones, use triangulation, which involves measuring distances from known points (e.g., satellites) to determine position.
• Dead Reckoning:This method estimates current position based on a previously known position, speed, and direction over time.
• Inertial Navigation:Utilizes accelerometers and gyroscopes to measure changes in velocity and orientation, calculating position from these changes.
• Celestial Navigation:Involves using the positions of celestial bodies (e.g., stars, sun) to determine location.
• Radio Navigation:Uses radio waves from terrestrial or satellite transmitters to determine position.

Types of Navigation Systems

Type	Description	Examples
Satellite Navigation	Uses a constellation of satellites to provide global positioning and timing information	GPS, GLONASS, Galileo, BeiDou
Inertial Navigation	Uses internal sensors (accelerometers, gyroscopes) to track position and orientation without external signals	INS (Inertial Navigation System)
Radio Navigation	Relies on terrestrial radio signals for position determination	VOR (VHF Omnidirectional Range), LORAN
Celestial Navigation	Uses positions of celestial bodies for navigation	Sextant, Marine Chronometer
Acoustic Navigation	Employs sound waves, usually underwater, for determining position	SONAR, Doppler Navigation
Dead Reckoning	Estimates position based on previous location, speed, and course	Marine dead reckoning, Air navigation

Key Components of Navigation Systems

• Receivers:Devices that receive and process signals from satellites or other sources.
• Sensors:Include accelerometers, gyroscopes, magnetometers, and barometers used in inertial and dead reckoning systems.
• Antennas:Essential for receiving signals in satellite and radio navigation systems.
• Processing Unit:Computes position, velocity, and trajectory based on received data and sensor inputs.
• Display/Interface:Provides navigational information to the user through maps, coordinates, or other formats.

Inertial Navigation Systems (INS)

• Principle:Measures changes in position and orientation using accelerometers and gyroscopes.
• Components:
  • Accelerometers:Measure linear acceleration.
  • Gyroscopes:Measure rotational movement.
  • Computing Unit:Integrates sensor data to determine position and orientation.
• Advantages:Independent of external signals, high precision over short distances.
• Applications:Aircraft, submarines, missiles, spacecraft.

Radio Navigation Systems

• VOR (VHF Omnidirectional Range):
  • Provides azimuth information to aircraft.
  • Uses VHF radio signals.
• LORAN (Long Range Navigation):
  • Utilizes low-frequency radio transmitters to determine position.
  • Historically used for marine and aviation navigation.
• DME (Distance Measuring Equipment):
  • Measures distance from an aircraft to a ground station.

Celestial Navigation

• Principle:Uses angles between celestial bodies and the horizon.
• Tools:
  • Sextant:Measures the angle between a celestial object and the horizon.
  • Chronometer:Provides precise time for calculations.
• Process:Determines position by solving spherical triangles formed by the observer, celestial body, and Earth's center.

Acoustic Navigation

• Principle:Uses sound waves to determine distance and position underwater.
• Techniques:
  • SONAR (Sound Navigation and Ranging):Sends sound pulses and measures their return time to determine distance.
  • Doppler Navigation:Uses the Doppler effect to measure velocity and determine position.

Applications of Navigation Systems

Field	Application
Aviation	Flight navigation, air traffic control, precision landing
Marine	Ship navigation, underwater exploration, fishing
Military	Troop movement, missile guidance, reconnaissance
Automotive	Vehicle navigation, fleet management, autonomous driving
Space	Spacecraft navigation, satellite positioning, exploration
Geospatial	Mapping, surveying, Geographic Information Systems (GIS)
Emergency Services	Search and rescue, disaster response, ambulance dispatch

Global Positioning System (GPS)

• The Global Positioning System (GPS) is a satellite-based navigation system that provides accurate location and time information anywhere on Earth.

History and Development

• Initial Concept:GPS was initially developed for military purposes by the United States Department of Defense in the 1970s.
• First Satellite Launch:The first GPS satellite was launched in 1978.
• Full Operational Capability:GPS became fully operational in 1995.
• Civilian Use:While initially restricted to military use, GPS was made available for civilian use in the 1980s, with significant accuracy improvement after the discontinuation of Selective Availability in 2000.

System Components

• Space Segment:
  • Consists of a constellation of at least 24 satellites orbiting Earth at approximately 20,200 kilometers altitude.
  • Satellites are arranged in six orbital planes to ensure global coverage.
• Control Segment:
  • Includes ground control stations that monitor and manage the satellite constellation.
  • Primary functions are satellite tracking, orbit determination, and clock correction.
  • Key control stations are located in Colorado Springs (Master Control Station), Hawaii, Ascension Island, Diego Garcia, and Kwajalein.
• User Segment:
  • Comprises GPS receivers used by civilians and military personnel.
  • Receivers calculate positions by processing signals from multiple GPS satellites.

Advantages

• Global Coverage:GPS provides accurate location information anywhere on Earth.
• High Precision:Offers high accuracy, typically within a few meters for civilian use and even better for military applications.
• Accessibility:Free and available for civilian use worldwide.
• Real-Time Information:Provides real-time location and time data.

Challenges

• Signal Blockage:GPS signals can be blocked or degraded by buildings, mountains, and dense foliage.
• Multipath Effects:Signals can reflect off surfaces, causing errors in position calculation.
• Atmospheric Conditions:Ionospheric and tropospheric conditions can affect signal propagation and accuracy.
• Reliance on Satellites:Dependence on satellite health and functionality; satellite failures can impact the system.

Summary of Global Navigation Systems

Aspect	GPS (Global Positioning System)	GLONASS (Global Navigation Satellite System)	Galileo	BeiDou	NavIC (Navigation with Indian Constellation)
Country/Organization	United States	Russia	European Union	China	India
Operational Since	1978 (initial launch), fully operational in 1995	1995 (initial), fully operational in 2011	Initial services in 2016, fully operational in 2020	2000 (initial), global coverage since 2020	2018 (regional), operational
Number of Satellites	Minimum of 24 operational satellites	24 operational satellites	24 operational satellites	35 operational satellites	7 operational satellites
Orbits	Medium Earth Orbit (MEO)	Medium Earth Orbit (MEO)	Medium Earth Orbit (MEO)	Medium Earth Orbit (MEO)	Geostationary and Geosynchronous orbits
Coverage Area	Global	Global	Global	Global	Regional (primarily India and surrounding areas)
Frequency Bands	L1, L2, L5	L1, L2	E1, E5, E6	B1, B2, B3	L5, S-band
Accuracy	5-10 meters (civilian), <1 meter (military)	5-10 meters (civilian), <1 meter (military)	1 meter (public), sub-meter (encrypted)	10 meters (public), sub-meter (encrypted)	10-20 meters (civilian), better with augmentation
Augmentation Systems	WAAS, EGNOS, MSAS, GAGAN	SDCM (System for Differential Correction and Monitoring)	EGNOS (European Geostationary Navigation Overlay Service)	SBAS (Satellite-Based Augmentation System)	GAGAN (GPS Aided GEO Augmented Navigation)
Uses	Civil, military, commercial, scientific	Civil, military, commercial	Civil, military, commercial	Civil, military, commercial	Civil, military, commercial
Unique Features	Widely used, high availability	Resilient to failures with GPS due to similar design	High precision, dual frequencies	Extensive coverage with more satellites	Focused on Indian region, complementary to GPS

Sources:

THEPRINT

PRACTICE QUESTION Q: With reference to quantum navigation technology, consider the following statements: 1.Quantum navigation utilizes quantum entanglement to improve the accuracy of positioning systems. 2.Quantum navigation systems can operate without relying on satellite signals. 3. Quantum superposition is the principle that allows particles to be in multiple states simultaneously, enhancing navigation accuracy. Which of the statements given above is/are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2, and 3 Answer: (a)