Unlocking Precision GNSSDO Applications in Action
From Drones to 5G: Timing Solutions for a Connected World
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In an era where precise timing underpins the functionality of global infrastructure, the need to incorporate a compact and resilient timing capability into a broad range of Position, Navigation, and Timing (PNT) systems has never been greater.
GNSS Disciplined Oscillators (GNSSDOs) are a popular and cost-effective method of delivering precise synchronization across various industries, including defence, telecommunications, financial markets, and critical utility infrastructure. Additionally, with the increasing number of GNSS jamming and spoofing incidents worldwide, it has become necessary to design resilient systems that can maintain time synchronization when GNSS is unavailable. As system designers seek to incorporate operational robustness into their system architecture, GNSSDO modules offer a viable method for achieving high-performance timing and GNSS resilience.
Microchip's GNSSDO modules are engineered for high performance, with a consistent design architecture across the portfolio. The modules can operate as a stand-alone system or can be incorporated into a larger system design, providing critical timing functionality. The portfolio has been designed around a standard hardware and software platform to make it as easy as possible to incorporate our GNSSDOs into your system.
This diagram illustrates the major components of our MD-015 GNSS disciplined atomic oscillator module, which is representative of the entire portfolio.
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A Microchip GNSSDO module can accept an external reference and synchronize (discipline) it to a local oscillator.
Typically, the external reference is the timing signal from a GNSS receiver, but Microchip's modules can also accommodate a 1 PPS or RF input from an external clock or timing source, such as a Microchip 5071B cesium atomic clock. The external reference signal provides timing accuracy and long-term frequency stability, while the local oscillator offers performance improvements, including short-term frequency stability, phase noise performance, holdover capability, and temperature stability. The combination of an external reference input and local oscillator enables the high levels of performance necessary for many of today's applications.
The choice of local oscillator varies across the portfolio, as it largely determines the overall performance of the module. The local oscillator is disciplined to an external frequency reference. This involves continuously adjusting the local oscillator's frequency and phase to align with the external reference. This approach ensures that the module maintains long-term accuracy and stability while compensating for the natural drift of the local oscillator. If the external frequency reference is no longer available, for example, if the reference is a GNSS signal and GNSS is being jammed, the module switches to auto-holdover mode and the local oscillator free-runs until a reliable reference is available to discipline. When the local oscillator is in free-run mode, the accuracy and stability of the module depends on the performance characteristics of the local oscillator.
The Microchip GNSSDO portfolio leverages in-house atomic and quartz oscillator technologies, including the Chip Scale Atomic Clock (CSAC), Miniature Atomic Clock (MAC), and Oven-Controlled Crystal Oscillators (OCXOs). As the manufacturer of these critical components, Microchip can easily adjust the modules to meet the performance requirements of end-user applications.
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Central to the Microchip GNSSDO module platform is a set of algorithms to improve the overall performance of the module. By designing and manufacturing the critical local oscillators, Microchip has a deep understanding of how aging and environmental factors affect their performance and has developed algorithms to compensate for these effects. The module platform has an integrated aging algorithm that measures and compensates for the aging of the local oscillator. Additionally, the holdover algorithms enhance the performance of the local oscillator when it is in holdover mode, which typically occurs during periods of GNSS denial. The disciplining algorithms and adaptive control loops measure the frequency offset of the local oscillator's output relative to the external reference and adjust the local oscillator's frequency to align with the external reference.
Finally, environmental compensation algorithms measure external factors, such as temperature or pressure change, and adjust the system to compensate for the changing environment, ensuring excellent performance in varied conditions.
Selecting which output to use from a GNSSDO module depends on the end-user application. The standard platform has several outputs on the 16-pin connector and directly off the module. The modules output a 1 PPS and 10 MHz signal off the board, a 1 PPS and HCMOS RF output over the 16-pin connector, and status and configuration information over the serial interface using the Vectron Serial Interface Protocol (VSIP), which is based on the NMEA-0183 communication protocol. The performance of a GNSSDO is largely dependent on the characteristics of the local oscillator. Therefore, choosing a local oscillator that has the performance characteristics required by the end application is one of the key considerations when deciding which GNSSDO to integrate into your system.
As a world leader in timing systems, Microchip has decades of experience in the timing domain and will work closely with you to understand your system requirements and provide guidance with your PNT system design.
PRODUCT PORTFOLIO >
The LM-010 is a PPS Disciplined Module designed to provide precise timing for Low Earth Orbit (LEO) applications that demand radiation tolerance coupled with stability and holdover capability.
As a standard platform module, the LM-010 provides both 1 PPS TTL and 10 MHz sinewave outputs that are disciplined to an external reference input. Internal to the module is Microchip's digitally corrected OCXO or low-power CSAC SA.45
MD-300 >
The MD-300 is Microchip's harsh environment GNSSDO module, coming in at a small 1.5 in by 2.5 in footprint.
The MD-300 has an embedded MEMS OCXO or TCXO as the local oscillator, enabling low g sensitivity, high shock and vibration tolerance, and low thermal transient response. Due to its small footprint (2.5 in by 1.5 in), weight and power, the MD-300 is ideal for applications like drones and manpacks. The module can discipline to an embedded GNSS receiver or external reference and output high performance 10 MHz and 1 PPS signals.
MD-013 >
The MD-013 ULTRA CLEAN GNSS Disciplined Oscillator Module outputs ultra-low phase noise and ultra-low Allan Deviation (ADEV) signals.
The module has an embedded 72-channel GNSS receiver for GPS, Galileo and GLONASS services. The module's ultra-low phase noise/ultra-low ADEV reference quartz crystal oscillator is disciplined to the external reference input or the GNSS receiver.
USE CASE STUDIES >
Modern radar systems are essential for a variety of military applications, including missile guidance and warning, surveillance, targeting, electronic warfare and navigation systems. Modern radar types include phased array, Active Electronically Scanned Array (AESA), multifunction, over-the-horizon and passive radar systems. These systems demand ultra-low noise and phase-coherent frequency references to achieve high performance in range resolution, target detection, Doppler processing, beamforming and clutter rejection.
GNSS Disciplined Oscillators (GNSSDOs) play a pivotal role in radar systems by providing the precise timing and frequency stability required for these advanced systems to operate effectively. The high-quality timing reference from a GNSSDO enables the following operations in modern radar systems:
SATCOM systems are critical to military operations, as they enable resilient global connectivity for voice, data, timing, ISR transmission and battlefield coordination. SATCOM systems can be deployed in a variety of environments and platforms including ground, airborne, maritime and space. These systems typically operate across a range of frequency bands including L-band, S-band, C-band, X-band, Ku-band, and Ka-band, making it difficult to jam the entire spectrum. SATCOM networks require precision timing for up/down conversion, carrier phase synchronization, modulation/demodulation and coordinated transmission protocols.
Operational Mechanics: In satellite communications, GNSS Disciplined Oscillators (GNSSDOs) provide precise timing for synchronization between ground stations and satellites, ensuring accurate frequency reference and timing alignment for voice, data and ISR applications. The disciplined oscillator ensures stable performance across various environmental conditions, supporting global connectivity for systems like the Defense Satellite Communications System (DSCS).
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SATCOM GNSSDO Application Considerations
Phase noise: An ultra-low phase noise reference is a critical requirement to ensure the spectral purity of transmitted signals and to minimize adjacent channel interference.
Frequency stability: Local oscillator instability can degrade the modulated signal quality and introduce phase errors into high-data-rate SATCOM links
Timing alignment: Networked SATCOM terminals require precise time alignment to ensure quality of service, reduce packet loss and enhance cryptographic key management.
Holdover: Tactical and airborne SATCOM systems often operate in GNSS-denied environments, where holdover timing is critical to maintaining performance
Size, Weight, and Power (SWaP): Tactical SATCOM systems operating on Unmanned Aerial Vehicles (UAVs) and vehicle platforms demand GNSSDOs with excellent shock and vibration tolerance, low-G sensitivity, low thermal transient response and low SWaP
Real-World Scenario
Teams on the battlefield communicate with each other and with the command-and-control center securely via satellite because local radio transmission is being jammed by the adversary. GNSSDOs ensure synchronized clocks for encrypted data transmission, maintaining accuracy in this contested environment.
Military vehicle platforms, including armored personnel carriers and main battle tanks, rely on precise time and frequency for navigation, communications, electronic warfare and battlefield networking.
Operational Mechanics: GNSS Disciplined Oscillators (GNSSDOs) provide time synchronization for networked operations, enabling command and control (C2) vehicles to distribute timing across systems and networks. They ensure rugged performance in harsh environments, withstanding temperature extremes, shock and vibration. Holdover supports missions during GNSS denial, while low phase noise enhances electronic warfare systems, like jammers.
Vehicle Platform GNSSDO Application Considerations:
Time Synchronization for Networked Operations: Precise timing is the cornerstone of enabling command and control vehicles to distribute synchronized timing across onboard systems, communications gear and battlefield networks.
Ruggedization for Harsh Environments: GNSSDOs used in vehicle platforms are subject to temperature extremes, mechanical shock and vibration, necessitating the use of local oscillators that can endure these environmental effects.
Holdover During GNSS Loss: GNSSDOs with atomic local oscillators or high-stability OCXOs provide timing holdover during periods of GNSS denial, enabling mission systems to continue normal operation.
Electronic Warfare (EW) Readiness: Platforms supporting EW systems require low-phase-noise frequency references to ensure performance of RF payloads like jamming, sensing and direction-finding systems.
Low SWaP for Platform Integration: Space-constrained vehicles benefit from highly integrated GNSSDOs with low SWaP requirements to reduce the overall power budget of the platform.
The deployment of 5G networks has transformed communication infrastructure on the battlefield, improving speed, latency, reliability, bandwidth and edge capabilities.
Military 5G networks enhance command and control, unmanned systems coordination and resilient mesh networking, all of which require precise timing for synchronization in dynamic, GNSS-denied environments. GNSS Disciplined Oscillators (GNSSDOs) provide stable references for Time Division Duplex (TDD) transmissions, accurate symbol timing and phase alignment across distributed 5G elements.
Application Considerations for GNSSDOs in 5G Networks
Dynamic Network Topologies: Mobile and ad hoc 5G deployments, common in military applications, require GNSSDOs that can maintain coherence without centralized control and that can support rapid synchronization across moving nodes.
Spectral Purity for High-Order Modulation: Modern systems using high-order modulation schemes like 1024-QAM are highly sensitive to impairments in signal quality, so they require GNSSDOs with excellent phase noise performance.
Phase and Time Synchronization: TDD-based 5G systems require tight phase alignment across all nodes in the network to avoid interference and ensure consistent quality of service.
High-Stability Holdover: In GNSS-denied environments, the network must maintain sub-microsecond time accuracy to prevent performance degradation or network outages.
A mobile command center sets up a 5G network to command-and-control (C2) unmanned vehicles and drones executing a surveillance mission in the area. GNSSDOs synchronize base stations, ensuring reliable, low-latency communication between the vehicle platforms and the C2 center.
Internet of Things (IoT) networks power smart cities, industrial automation, agriculture and environmental monitoring. These networks rely on precise timing to synchronize devices and ensure efficient communication from the core to the edge.
Operational Mechanics: GNSS Disciplined Oscillators (GNSSDOs) in IoT networks provide precise timing to synchronize distributed devices, such as sensors and actuators. They discipline a high-quality oscillator (e.g., TCXO or OCXO) to GNSS signals, generating stable 1 PPS (pulse per second) and frequency outputs (e.g., 10 MHz). This ensures accurate timestamping for data logging, synchronized communication protocols and coordinated device actions. When GNSS signals are lost due to urban canyons, foliage or jamming, the GNSSDO enters holdover mode and uses advanced algorithms to maintain timing accuracy by compensating for environmental factors like temperature and pressure.
Real World Examples:
Smart Cities: GNSSDOs synchronize traffic lights and Vehicle-to-Infrastructure (V2I) systems in cities, optimizing traffic flow and reducing congestion.
Industrial Automation: GNSSDOs can be used in factories to synchronize production line sensors and robots to enhance the efficiency of manufacturing processes.
GNSSDO Considerations in IoT Networks
SWaP: IoT networks require compact, low-power GNSSDOs for integration into edge devices and gateways.
Holdover Stability: GNSSDOs with good holdover enable continued performance in remote or urban environments with intermittent GNSS access.
Environmental Hardening: Environmental tolerance supports outdoor applications like smart city infrastructure.
In a smart factory, sensors and machines need to be synchronized for efficient production. GNSSDOs ensure precise timing between equipment, allowing robots and conveyor belts to operate in harmony.
Commercial radar systems, including weather radar networks, air traffic control, maritime navigation and emerging automotive applications, depend on GNSS Disciplined Oscillators (GNSSDOs) for synchronized data, accurate ranging and Doppler processing. These systems require precise timing to ensure reliable performance in critical applications like disaster preparedness, aviation safety and maritime operations.
Operational Mechanics: GNSSDOs in commercial radar systems deliver a stable reference frequency and timing signal to synchronize transmitters and receivers which is critical for accurate target tracking and surveillance. They discipline a high-quality oscillator (e.g., quartz or rubidium) to GNSS signals via a tracking loop, locking to GNSS time when signals are available. During disruptions like jamming or spoofing, the GNSSDO switches to holdover mode, maintaining the last known frequency and phase using advanced algorithms that compensate for environmental factors such as temperature and pressure.
Real-World Examples
Weather Radar: GNSSDOs are used in systems to monitor precipitation and wind patterns and provide data for severe weather warnings.
Air Traffic Control: GNSSDOs synchronize radar systems to track aircraft positions accurately, enhancing safety at airports.
Maritime Radar: In radar systems, GNSSDOs are employed for collision avoidance on commercial ships
Automotive Radar: GNSSDOs support ADAS and add features like adaptive cruise control to vehicles
Commercial radar systems require GNSSDOs with low phase noise for Doppler accuracy and high stability for distributed networks. Environmental tolerance is critical for outdoor deployments, such as weather radar stations exposed to extreme temperatures or maritime radars on ships.
A weather radar station tracks storm systems to provide early warnings for severe weather events. GNSSDOs are utilized for accurate timing, enabling precise measurements and estimations of the storm’s trajectory.
Commercial drones are transforming industries like mapping, agriculture, 5G network support and logistics. These industries rely on GNSS Disciplined Oscillators (GNSSDOs) for precise navigation, sensor synchronization and coordinated operations. GNSSDOs synchronize position data from sensor measurements for accurate 3D models, which enables high-precision georeferencing for mapping and surveying. GNSSDOs also support 5G network extension by providing timing references for drones acting as temporary base stations, ensuring network synchronization. In swarm operations, GNSSDOs enable coordinated flight patterns, which are critical for applications like drone light shows or search and rescue missions.
GNSSDOs in commercial drones provide precise timing for navigation systems to determine accurate positions using GNSS signals. They calculate the time of arrival of satellite signals to compute the drone’s location, which is essential for tasks like mapping and delivery. When GNSS signals are available, the GNSSDO locks to them for accurate timing. In areas with signal loss, such as urban canyons or dense foliage, it operates in holdover mode, using an internal oscillator and algorithms to maintain timing accuracy until signals are reacquired.
Agriculture: Drones use GNSSDOs for crop monitoring and mapping fields with centimeter accuracy.
Surveying: GNSSDOs support topographic mapping with drones, achieving high accuracy for land development projects.
Application Considerations
Size, Weight, and Power (SWaP): Commercial drones require GNSSDOs with ultra-low SWaP for small platforms with limited power budgets.
Environmental Tolerance: Commercial drones inherently operate in high-vibration environments, requiring GNSSDOs that are resistant to these effects.
Holdover: Drones operating in urban or remote environments, where the GNSS connection may be lost for short periods of time, require GNSSDOs with good holdover capabilities.
A fleet of agricultural drones relies on GNSSDOs for synchronized data collection, ensuring consistent measurements across varying terrain in support of precision farming.
The financial sector, particularly High-Frequency Trading (HFT), relies on precise timing to ensure accurate timestamping of transactions to maintain fairness, transparency and compliance with stringent regulatory standards. Financial markets are subject to stringent regulations that mandate precise timestamping to ensure accountability and prevent market manipulation.
Operational Mechanics: GNSS Disciplined Oscillators (GNSSDOs) discipline a high-quality oscillator-to-GNSS signals, delivering a stable reference frequency and time pulse (e.g., 1 PPS Regulations such as the Markets in Financial Instruments Directive II (MiFID II) mandate timestamp accuracy within 100 microseconds, making reliable timing solutions indispensable for stock exchanges, banks and financial technology (fintech) firms.
Timestamp accuracy is essential for:
Trade Execution Order: Financial exchanges rely on timestamps to determine the exact order of trade submissions. If timestamps are inaccurate, a later trade could be recorded as occurring before an earlier one, disrupting the first-come, first-served principle and undermining market fairness.
Preventing Exploitation: Precise timestamps prevent manipulative practices, such as “quote stuffing,” where traders flood the market with orders to delay competitors. Accurate timing ensures these activities are detectable and attributable.
Real-World Implications:
In 2010, the “Flash Crash” saw U.S. markets plummet due to rapid, automated HFT trades. Inaccurate timestamps could have hindered investigations into the event, delaying regulatory responses. Precise timestamping that is enabled by GNSSDOs ensures that events are accurately recorded so they can be analyzed.
Cost of Errors: A 2013 study estimated that a 1-millisecond timing error in HFT could cost a firm $1 million per trade in missed opportunities or losses.
Regulatory Fines: In 2018, a major exchange was fined $14 million for timestamp inaccuracies that obscured trade data, highlighting the financial stakes of precise timing.
Commercial navigation systems in aviation, maritime and land-based transportation depend on Positioning, Navigation, and Timing (PNT) to ensure accurate positioning, which is critical for safety.
GNSS Disciplined Oscillators (GNSSDOs) provide precise timing references that enhance the performance of navigation systems, particularly those relying on GNSS. GNSSDOs calculate vehicle positions by measuring the time of arrival of GNSS signals, ensuring that GNSS receivers and Inertial Navigation Systems (INS) maintain precise time synchronization to enable accurate Position, Velocity and Attitude (PVA) solutions. In GNSS-denied environments like tunnels or urban canyons, the GNSSDO operates in holdover mode, using an internal oscillator to maintain timing accuracy until signals are reacquired to ensure safe and reliable navigation.
Aviation: GNSSDOs support flight management systems in commercial aircraft for precise navigation
Maritime Navigation: GNSSDOs are used in ship navigation systems for accurate positioning.
Land-Based Transportation: GNSSDOs enable fleet management for logistics companies and support autonomous vehicle navigation.
Key Requirements
High Positioning Accuracy: Essential for safety-critical applications, such as aviation’s ADS-B with < 2-second latency
Environmental Resilience: Operation in diverse conditions, including high altitude, high shock and vibration and maritime environments
Holdover Performance: To maintain accuracy during GNSS outages ranging from a few minutes to several hours
Commercial aircraft use GPS-based navigation systems for precision landing in low-visibility conditions. GNSSDOs provide accurate timing to the landing and navigation systems, enhancing safety and efficiency in air travel.
Scientific research in fields like physics, astronomy and metrology relies on ultra-precise timing references to conduct accurate experiments and observations. Whether the application is synchronizing particle detectors, timing celestial events, or maintaining time standards, precise timing is fundamental to advancing scientific knowledge.
GNSS Disciplined Oscillators (GNSSDOs) provide nanosecond accuracy and low jitter, which are critical for scientific applications. In particle physics, precise timing is essential for time-of-flight measurements and synchronizing data from multiple detectors, as seen in experiments at facilities like CERN. In astronomy, GNSSDOs coordinate global telescope networks to study transient phenomena like pulsars or gravitational waves. Metrology laboratories use GNSSDOs to maintain traceable time standards that support critical infrastructure like telecommunications and power grids.
Particle Physics: Synchronize detectors in particle accelerators for precise particle collision timing
Astronomy: Used in pulsar timing arrays to measure signal arrivals from space
Metrology: Serve as reference clocks to maintain UTC time standard
Ultra-High Stability: For long-term experiments and observations
Low Phase Noise and Jitter: To ensure precise measurements
Customizable Outputs: To integrate with various scientific instruments
Telescopes worldwide use GNSSDOs to synchronize and timestamp observations, capturing detailed images of celestial events with high accuracy.
The rollout of 5G networks marks a transformative era in telecommunications, delivering ultra-fast speeds, minimal latency and massive device connectivity to power applications like smart cities, industrial automation and enhanced mobile broadband. At the heart of these networks lies the critical need for precise timing and synchronization to ensure seamless operation. Our GNSS Disciplined Oscillators (GNSSDOs) provide the high-precision timing solutions required to meet the stringent demands of commercial telecom and 5G networks.
In 5G networks, GNSSDOs synchronize macro base stations, small cells and edge nodes, enabling cohesive operation across distributed infrastructure. They support critical features like beamforming—where precise timing aligns antenna arrays to focus signals—and massive Multiple-Input, Multiple-Output (MIMO), which increases network capacity through multiple simultaneous connections.
Application Considerations:
Sub-Microsecond Synchronization: GNSSDOs deliver timing accuracy within nanoseconds, exceeding the 1.5 microsecond requirement for TDD synchronization to ensure interference-free operation.
Low Phase Noise: Critical for high-order modulation schemes (e.g., 1024-QAM), low phase noise maintains signal clarity to reduce errors and improve data throughput.
Holdover Performance: During GNSS outages, GNSSDOs switch to holdover mode using high-stability oscillators to maintain timing accuracy for hours, ensuring network continuity in urban canyons or disrupted environments.
Environmental Resilience: Designed to operate across wide temperature ranges (−40°C to 80°C) and withstand vibration, GNSSDOs are well suited for outdoor 5G infrastructure.
Compact and Low-Power Designs: Optimized for Size, Weight and Power (SWaP), GNSSDOs support small cell deployments and edge devices, reducing operational costs.
Real-World Scenarios:
A city-wide 5G network supports autonomous vehicles and smart city infrastructure. GNSSDOs synchronize base stations across the city, including small cell sites, ensuring wide coverage and low-latency communication.
From nano drones to high-altitude, long-endurance platforms, Unmanned Aerial Vehicles (UAVs) have become critical for military Intelligence, Surveillance and Reconnaissance (ISR) and electronic warfare.
In UAV platforms, GNSS Disciplined Oscillators (GNSSDOs) provide precise timing for navigation, communication and payload synchronization, ensuring accurate positioning and swarm coordination. They discipline a lightweight oscillator to GNSS signals to maintain lock under normal conditions. When GNSS signals are lost due to obstructions like urban canyons or jamming, GNSSDOs enter holdover mode, using advanced algorithms to maintain timing accuracy until signals are reacquired.
UAV Application Considerations
UAV swarms require tight synchronization for coordinated mission execution. GNSSDOs provide the necessary coherent clock source for shared time/frequency domains between platforms.
ISR and electronic warfare UAVs benefit from GNSSDOs that contain advanced holdover clocks to maintain system functionality when GNSS is denied or jammed.
Communication links, especially in the L-band or C-band, demand ultra-low phase noise GNSSDOs to minimize spectral regrowth and ensure signal clarity.
A military UAV is conducting reconnaissance and is using the timing from a GNSSDO for accurate navigation and timestamping of intelligence data. The UAV also relies on the holdover timing from the GNSSDO in the event of GNSS denial and RF jamming from the adversary.
Tactical radio systems provide secure and reliable voice and data links in challenging environments including urban canyons, indoors and electromagnetic jamming.
Modern tactical radio systems require precise time and frequency synchronization for advanced functions like frequency hopping, secure and encrypted communications, timing synchronization across distributed radio networks and the operation of advanced waveforms. GNSS Disciplined Oscillators (GNSSDOs) are often implemented within tactical radios to provide the essential timing stability required to maintain synchronization and holdover during GNSS denial and RF jamming.
GNSSDO Importance in Radio Operations:
Stable frequency reference for secure communications protocols (e.g., frequency hopping spread spectrum and encryption keys)
Phase coherence for advanced waveform generation and signal processing
Low phase noise for reduced signal distortion and adjacent channel interference
Holdover capability for continued operation when GNSS signals are unavailable or jammed
Synchronization of mobile ad-hoc networks (MANET)
Special operations use tactical radios with frequency hopping to avoid detection. GNSSDOs provide the timing for synchronization between dismounted radios, ensuring secure and reliable communication in combat zones.
