Search Results

Stay ahead in PNT technology with MOSA & CMOSS. Learn how open systems architecture is revolutionizing the industry. Home • Applications • MOSA & CMOSS MOSA & CMOSS: Advancing PNT Through Open Systems Architecture What is MOSA? • What is CMOSS? • What is CMFF? • Why CMOSS? • How is CMOSS Being Implemented? • CMOSS Architecture What is MOSA? The Modular Open Systems Approach (MOSA) is a DoD-mandated strategy that ensures interoperability, scalability, and rapid modernization across defense platforms. CMOSS is a direct implementation of MOSA, enabling cross-service compatibility and vendor-agnostic solutions. MOSA prioritizes open standards, such as: CMOSS – Standardized architecture for C5ISR/EW systems SOSA™ – Sensor Open Systems Architecture for joint-service interoperability VITA 65 / OpenVPX™ – Open hardware standards for embedded systems By aligning CMOSS with MOSA principles, the DoD ensures that future systems are: More affordable due to vendor competition More flexible through plug-and-play technology More resilient with built-in cybersecurity & anti-obsolescence strategies What is CMOSS? CMOSS is a suite of open standards designed to reduce size, weight, power, and cost (SWaP-C) of C5ISR and Electronic Warfare (EW) systems. By enabling hardware and software interoperability, CMOSS enhances flexibility , adaptability , and modularity across military platforms. CMOSS moves away from traditional “stove-piped” systems that require separate, proprietary hardware. Instead, it leverages a modular, standards-based approach that allows multiple vendors to develop interoperable solutions. What is CMFF? The CMOSS Mounted Form Factor (CMFF) expands CMOSS-based architectures for mounted vehicle platforms, providing: Compact, ruggedized hardware for combat vehicles & mobile platforms Seamless integration of communications, EW, & SIGINT functions Standardized interfaces for rapid capability upgrades CMFF ensures that ground vehicles benefit from the same CMOSS-based advantages seen in other military domains. Key Acronyms MOSA = Modular Open Systems Approach EW = Electronic Warfare CMOSS = C5ISR/EW Modular Open Suite of Standards CMFF = CMOSS Mounted Form Factor C5ISR = Command, Control, Communications, Computers, Cyber, Intelligence, Surveillance, and Reconnaissance CMOSS and the SOSA Initiative CMOSS is a foundational component of the Sensor Open Systems Architecture (SOSA)™ initiative, which the U.S. Military actively participates in. SOSA aligns with MOSA (Modular Open Systems Approach), ensuring common standards for open, adaptable, and rapidly upgradable military systems. LEARN MORE Safran Federal Systems is a proud member of the Sensor Open Systems Architecture™ Consortium. Why CMOSS? Historically, C5ISR and EW systems have been developed independently, leading to incompatibility and inefficiencies. CMOSS creates a unified architecture that integrates these technologies into a single, interoperable framework, delivering key advantages: Reduces Integration Costs & Risks Standardized interfaces simplify development and deployment Extends System Lifespan Modular upgrades prevent costly full-system replacements Facilitates Interoperability & Reuse Multiple vendors can contribute to a common ecosystem Accelerates Fielding & Deliveries Open architecture speeds up new technology adoption By converging multiple functions into a shared hardware and software ecosystem, CMOSS provides military forces with a future-proof, scalable solution for modern battlefield operations. How is CMOSS Being Implemented? CMOSS is actively shaping next-generation military systems by standardizing hardware, software, networking, and data sharing across platforms. There are several key components of CMOSS implementation: Universal A-Kit Enables plug-and-play fielding of new capabilities via modular cards in a common chassis Pooled RF Resources Shared antennas & amplifiers for Communications, Electronic Warfare (EW), and Signals Intelligence (SIGINT) systems Integrated Processing & Displays Shared computing resources enhance situational awareness & decision-making Common PNT Data Services Standardized Position, Navigation & Timing (PNT) services for all mission-critical systems CMOSS Architecture Software Layer • Enables portability of software applications across hardware platforms • Allows mission-specific software framework Functional Decomposition • Enables resource sharing (e.g., RF components, antennas, amplifiers) • Defines standardized interfaces for seamless integration • Supports best-of-breed rapid technology upgrades Hardware Layer • Enables capabilities to be fielded as cards in a common chassis • Standardizes physical, electrical, and environmental specifications Network Layer • Provides connectivity and defines interfaces within the platform • Enables legacy systems to integrate with the converged architecture U.S. Army Selects Safran Federal Systems as a Top-5 Winner in XTech CMOSS PNT Plugfest Competition Safran Federal Systems (formerly Orolia Defense & Security) was recognized for its outstanding technology achievements at the 2021 xTech Plugfest competition. Selected as a Top-5 Winner, the company demonstrated the potential of CMOSS-based Positioning, Navigation, and Timing (PNT) solutions to impact military operations within the United States Army and Department of Defense Read the Full Press Release Open Systems PNT Card Open-Architecture Framework Delivering Assured PNT LEARN MORE WHITE PAPER Addressing Assured PNT Needs through Open Standards This white paper guides engineering staff, integrators, and decision makers in recognizing the need for assured PNT in modernized systems. The benefits of assured PNT can be realized and addressed through the adoption of open standards. Read the White Paper

Safran Federal Systems is a trusted DoD mission partner providing cross-cutting Position, Navigation and Timing (PNT) solutions from the lab to the field. Built for the Threat. Ready for the Mission. Safran Federal Systems is a trusted defense mission partner and industry leader in Assured Positioning, Navigation, and Timing (A-PNT) and Geospatial Intelligence. Our cross-cutting capability set spans GNSS simulation, NAVWAR, inertial navigation, and AI — with continued investment in emerging areas like Quantum Sensing. Through open systems architecture and a commitment to relentless innovation, we deliver proven solutions to the warfighter across all domains. NEWS Safran Federal Systems Achieves CMMC Level 2 Certification, Ensuring Uninterrupted Support for Defense Customers Safran Federal Systems, a trusted provider of positioning, navigation and timing solutions for U.S. federal and defense operations, Thursday announced it has achieved Cybersecurity Maturity Model Certification (CMMC) Level 2, positioning the company among an early wave of Defense Industrial Base suppliers to meet this critical compliance benchmark ahead of broader enforcement deadlines. PRESS RELEASE Dominate the Battlefield with Advanced NAVWAR Tools— Test, Detect, Defeat LEARN MORE → Safran Presents on Next-Generation MEMS Gyro at Joint Navigation Conference LEARN MORE → OUR EXPERTISE Safran helps customers succeed by designing the highest quality products at the best value, leveraging subject matter experts to provide unparalleled solutions, reducing cost, risk and schedule. GNSS Testing & Simulation Navigation Warfare (NAVWAR) Assured Positioning, Navigation & Timing (PNT) Inertial Navigation and IMUs Artificial Intelligence Custom Solutions INDUSTRY LEADING CAPABILITIES CRPA Testing Our CRPA testing solutions provide unrivaled scalability, phase-coherency and calibration, from testing entire PNT systems to antenna electronics. Discover why groups like the U.S. Air Force Guided Weapons Evaluation Facility trust us to support their test environment. M-Code Our M-Code PNT solutions support you during all phases of your mission, from testing and simulation to operating in the field. Discover why the world's most critical defense systems rely on us to provide M-Code. We are delivering today with no additional lead time. Navigation Warfare Navigation Warfare is emerging as a powerful non-kinetic strategy to counter adversaries. Our solutions, forged through years of operational expertise and relentless innovation, empower you to dominate the spectrum in the face of evolving threats. LEARN MORE LEARN MORE LEARN MORE MOSA and CMOSS Open Systems Architecture is the DNA behind our rapid prototyping and customer-focused solutions. As MOSA and CMOSS shape the future, we’re committed to aligning with these standards to deliver flexible, scalable, and enduring PNT within the CMFF framework. Search and Rescue Our signaling technology ensures safety in the most rugged and remote environments, with the world’s first Cospas-Sarsat certified second-generation capability. Discover why the U.S. Army chose us to produce beacons to meet their specific requirements. LEARN MORE LEARN MORE Success Story : Accelerating Innovation for U.S. Special Operations Forces In a fast-paced defense landscape, Safran Federal Systems, in close partnership with Anduril, played a pivotal role in rapidly delivering advanced capabilities to support U.S. Special Operations Forces. SUCCESS STORY Elevate Your Career Safran Federal Systems is growing and in need of high-quality talent. We offer competitive salaries, benefits, and flexible positions. A creative environment and fun culture can be checked off your list! Think you have what it takes to be on our team? Apply today. VIEW OPEN ROLES SPEAK TO SALES

Protect your PNT systems from emerging threats like GPS jamming and spoofing. Learn how to safeguard your devices effectively. Home • Applications • GPS Jamming and Spoofing GPS Jamming and Spoofing: Protect Your PNT Systems from Emerging Threats GPS jamming and spoofing attacks are a growing concern as the accessibility of software-defined radios (SDRs) has made these threats more widespread than ever before. In order to safeguard PNT systems from potential disruptions, it is crucial to conduct proactive testing against real-world interference. Understanding the Threats of GPS Jamming and Spoofing Attacks Interference in GPS systems, such as jamming and spoofing attacks, can pose serious threats to the reliability and security of navigation systems that rely on global navigation satellite systems. Spoofers can generate false signals that can mislead GPS receivers about their position, potentially leading to dangerous consequences. As these evolving threats continue to grow in sophistication, it is crucial for organizations to implement effective detection and mitigation strategies to protect their PNT systems and ensure the integrity of their GPS data. By understanding the potential impact of GPS jamming and spoofing , governments can better protect their critical infrastructure and uphold the reliability of accurate position data. What is the difference between GPS Jamming & Spoofing? Jamming involves the intentional interference with GPS signals, disrupting communication between satellites and receivers. This can result in inaccurate positioning data or a complete loss of signal. Spoofing involves the manipulation of GPS signals to deceive receivers into believing they are in a different location. Testing Against Real-World Interference Testing against real-world interference is crucial in ensuring the reliability and accuracy of GPS and GNSS systems. With the increasing threat of jamming and spoofing attacks, it is essential to detect and mitigate these interferences effectively. By replicating real-world environments and simulating simultaneous generation of jamming and GNSS signals, this mitigation technique can accurately assess the system's ability to withstand interference and ensure genuine signals are being received. This proactive testing approach is key to ensuring accurate position data and the uninterrupted functionality of PNT systems in the face of growing security challenges. Challenges & Limitations with Traditional Jamming Testing When it comes to traditional jamming testing for PNT systems, there are various challenges and limitations that organizations face. One of the main challenges is that traditional testing methods may be limited in their ability to accurately replicate real-world jamming scenarios, leading to potential gaps in assessing the resilience of GNSS signals. This highlights the need for more advanced technology to effectively protect PNT systems from the increasing threats of jamming and spoofing attacks. Users required to attach a separate signal generator for each interference waveform to be generated The number of interference sources is limited to the number of signal generators available Signal generators would need to be integrated into software or be operated real-time by an engineer Jamming power levels were determined based on what signal level was to be received at the receiver front end independent of the location of the simulated jammer or transmit power BroadSim : The Ultimate GNSS Jamming & Spoofing Simulator BroadSim is transforming GNSS testing by allowing simultaneous generation of jamming and spoofing GNSS signals— all within a single system, making it easier than ever to replicate complex real-world environments. With BroadSim, generate high-fidelity interference signals across multiple types, including Carrier Wave , Additive White Gaussian Noise (AWGN), IQ File Playback , and more . Featuring intuitive Skydel software control and 4 RF outputs, BroadSim supports multiple simultaneous constellations. Hundreds of interference signals can be generated with 1 RF output Each interference signal within 1 RF output can have different power levels, modulations, and locations Jamming can be turned on and off through the Skydel GUI and API during runtime Users can specify the location, power, and movement of jamming transmitters and BroadSim will calculate the received power at the receiver based on the location to the transmitted and user-selected loss model Enables users to create real-world threat scenarios to better support the warfighter A Look Inside BroadSim Jamming Scenario Jamming Scenario Play Video Facebook Twitter Pinterest Tumblr Copy Link Link Copied Our team developed a plugin to showcase BroadSim’s hardware-in-the-loop (HILT) and advanced jamming capabilities via the Kerbal Space Program (KSP) computer game. BroadSim generates and transmits the corresponding RF signals to a GNSS receiver and a spectrum analyzer , whose data is collected and plotted on the same screen. 6 red spheres appear in the flight space, each representing a jammer with a unique frequency, power level, and modulation. The aircraft nears a jammer made up of CW tones offset by 1MHz with varying power levels. The aircraft in the video is controlled through a joystick. The path of the actual flight is shown by the red trail . As the airplane is maneuvered, its real - time location is sent to BroadSim. The reported location of the receiver is shown by the green trace and the spectrum from the spectrum analyzer is shown in the lower right-hand corner (center at GPS L1). When the aircraft flies directly through the jammer, the receiver is jammed to the point that it cannot track the GNSS signals and begins to drift in a straight line away from the jamming source. Simultaneous simulation of GNSS signals across multiple constellations can be achieved leveraging the Skydel Simulation Engine , including advanced jamming and spoofing . LEARN MORE Securing Your PNT Systems from GPS Jamming and Spoofing Attacks Protecting your PNT systems from the evolving threats of GPS jamming and spoofing requires advanced testing capabilities against real-world interference. Testing is particularly important for critical applications such as aircraft navigation, where false location information could have disastrous consequences. By utilizing signal generators such as BroadSim , warfighters can simulate different types of GPS interference, including jamming and spoofing, to ensure that PNT systems remain secure in the face of evolving threats. Leveraging the use of M-code for classified testing environments can further provide a secure platform for assessing the capabilities of PNT systems under various threat scenarios. By staying proactive and implementing comprehensive strategies, warfighters can better understand the vulnerabilities of their systems to defending against GPS spoofing and jamming to maintain the integrity of their operations.

Interested in a navwar career with Safran? See if you qualify for any of our open positions. Home • Company • Open Roles Open Roles Safran Federal Systems is committed to providing a work environment that is free from unlawful discrimination and harassment in any form. Safran Federal Systems will make reasonable accommodations for qualified individuals with disabilities unless doing so would result in an undue hardship. If you are interested in applying for employment and feel you need a reasonable accommodation pursuant to the ADA, you are encouraged to contact us at careers@safranfs.com . Browse Open Roles Financial Analyst Rochester, NY Permanent Full-Time Finance Button Principal GNSS/PNT Systems Engineer Rochester, NY Permanent Full-Time Engineering Button Senior Software Engineer Rochester, NY Permanent Full-Time Engineering Button Engineering Technician Rochester, NY Permanent Full-Time Engineering Button Lead Project Manager Rochester, NY Permanent Full-Time Project Management Button Manufacturing Technician II Rochester, NY Permanent Full-Time Production Button Lead Program Manager Rochester, NY Permanent Full-Time Program Management Button Senior Sales Manager Washington, DC Permanent Full-Time Sales Button Senior Sales Manager Rochester, NY Permanent Full-Time Sales Button

This paper outlines how to turn on/off spoofers and repeaters, adjust their power, and set a pseudorange offset. An example scenario will show the manual process by configuring the Skydel instances and the automated process by utilizing Skydel’s Python API. Home • PNT Library • Controlling Power & Pseudorange Offsets of a Repeater Threat Controlling Power & Pseudorange Offsets of a Repeater Threat DOWNLOAD PDF By Jaemin Powell DOWNLOAD PDF

This guide discusses applications and use cases for CRPAs, and methods for testing them. It explores various test solutions available today, and helps you choose the right solution for your specific application. Home • PNT Library • An Engineer’s Guide to CRPA Testing An Engineer’s Guide to CRPA Testing DOWNLOAD PDF By Tim Erbes Introduction In the ever-evolving landscape of GPS navigation and positioning, Controlled Reception Pattern Antennas (CRPAs) are revolutionizing defense and critical infrastructure. These advanced systems are crucial for protecting against jamming and spoofing threats, which can disrupt operations in high-stakes environments. We are providing a comprehensive overview of CRPA testing methods, technologies, and best practices based on the insights from Safran Federal Systems' white paper, Engineer’s Guide to CRPA Testing. For the full white paper and in-depth analysis, download the PDF . Who Should Read This White Paper? • GNSS/RF Test Engineers • GNSS/RF Systems Engineers • PNT Engineers • Navigation Engineers • NAVWAR Engineers • Signal Processing Engineers • Avionics Engineers • Program Managers What Are CRPAs, and Why Are They Important? CRPAs, or Controlled Reception Pattern Antennas, are multi-element antenna systems designed to reduce RF interference. By forming nulls in the direction of jammers or spoofers, CRPAs ensure that GPS receivers only process true satellite signals. These antennas are increasingly common in the defense sector, where robust anti-jamming and anti-spoofing capabilities are essential. Key benefits of CRPAs include: • Dynamic Threat Adaptation : Nullifies interference in real-time. • Enhanced Navigation Security: Maintains signal integrity under adverse conditions. • Wide Application: Used in UAVs, ground vehicles, and naval systems. Why Is CRPA Testing Critical? Rigorous testing ensures that CRPAs perform reliably in real-world scenarios. Without proper validation, these systems may fail to counteract advanced jamming and spoofing threats. Testing not only validates the design but also identifies performance limits and areas for improvement. CRPA Testing Methods 1. Record Replay Testing This cost-effective method uses recorded GPS data for simulations. While realistic, it lacks flexibility since recorded data cannot be modified. 2. GNSS Simulation GNSS simulators, like Safran’s Skydel-powered systems, allow for fast iteration speeds and high flexibility. These simulators support: • Threat simulations (jammers and spoofers). • Encrypted signals for classified defense systems. • Scalable architecture for multi-element testing. 3. Anechoic Chamber Testing An anechoic chamber provides a controlled environment for over-the-air (OTA) testing of CRPAs. It evaluates both antennas and electronics, ensuring comprehensive system performance validation. However, it requires significant upfront investment and setup. 4. Field Testing Field testing replicates real-world conditions by introducing actual threats. While effective, this method is costly and limited by environmental variables and regulations. Wavefront Simulation: A Game-Changer for CRPA Testing What is Wavefront Simulation? Wavefront simulation uses software-defined radios to simulate GNSS signals and threats, delivering unmatched precision and scalability. Key features include: • Phase Alignment: Ensures accurate signal timing across antenna elements. • Real-Time Jamming and Spoofing: Simulates hundreds of threats simultaneously. • Scalability: Supports up to 16 antenna elements and thousands of signals. • Automation: Enables quick setup and repeatable tests with minimal manual intervention. Advantages Over Traditional Methods Wavefront systems are lab-ready and do not require complex installations like anechoic chambers. They allow for dynamic simulations, enabling engineers to test under extreme conditions without leaving the lab. Key Features of a Robust CRPA Testing System When selecting a testing system, look for the following: • Built-In Jamming and Spoofing: Essential for simulating real-world threats. • Encrypted Signal Support: Critical for classified defense applications. • Scalability: The system should adapt to future needs, including additional elements or signals. • Automation: Streamlined calibration and testing workflows to save time. • Cost Efficiency: Long-term savings through software-defined, upgradeable systems. Common Questions About CRPA Testing How do CRPAs counter jamming and spoofing? CRPAs dynamically nullify interference using null steering and beamforming techniques, isolating true satellite signals while ignoring others. What’s the best way to test CRPAs? The ideal approach combines methods. GNSS simulation offers flexibility and speed, while anechoic chambers provide comprehensive OTA testing for full systems. How scalable are modern CRPA testing systems? Safran’s wavefront systems are highly scalable, supporting additional elements, signals, and future updates with minimal hardware changes. Is it possible to convert scenarios from my legacy platform? Short answer—Yes! Switching systems can be overwhelming—we feel you. Let us handle the heavy lifting: we make it easy to migrate your scenarios so you can transition seamlessly—without starting from scratch. Conclusion Testing CRPAs is no longer an optional step—it’s a critical process to ensure navigation security in high-threat environments. Safran Federal Systems’ innovative solutions, including wavefront simulation and Skydel technology, provide defense professionals with the tools needed to validate performance, identify vulnerabilities, and prepare for evolving threats. DOWNLOAD PDF

This white paper guides engineering staff, integrators, and decision makers in recognizing the need for assured PNT in modernized systems. The adoption of open standard elements leads to improvements in technical performance and sustainment of systems... Home • PNT Library • Addressing Assured PNT needs through Open Standards Addressing Assured PNT needs through Open Standards DOWNLOAD PDF By Brent Abbott Executive Summary With all military services actively focused on modernizing system capabilities and bringing the latest enhanced capabilities to the warfighter, Orolia continues to align our capabilities to include the integration of Military Code (M-Code) and advanced sensors to maintain trusted and assured PNT data even in a GPS denied and/or threatened environment. The benefits of assured PNT can be realized and addressed through the adoption of open standards. Section 1 of this document describes the need for assured PNT in any modernized system. Section 2 describes the adoption of open system architectures and its impact on process and business rules. Section 3 describes the adoption of SOSA and FACE and the impacts on competition generation. Section 4 covers the ability of the Air Force to rapidly innovate and plan. This document is intended to guide engineering staff, integrators, and decision makers in recognizing the need for assured PNT in modernized systems. The adoption of open standard elements leads to improvements in technical performance and sustainment of systems through the use of assured PNT in modernized systems. Section 1 - Assured PNT backbone Assured PNT is more than just beneficial. It is an integral part to any system as the basis of assured position, navigation and timing needed to maintain system operability. Position and navigation are required to update the warfighter with critical, real-time accurate location that can be used to act and react as necessary. Timing, arguably the most critical piece, ensures that the combination of system components operate at the highest capacity possible. Maintaining high operational performance is paramount to warfighter safety and success. Achieving and maintaining high operational performance is not an easy task. With each new mission, the environment will have an impact on the PNT solution used to drive system performance. Maintaining the integrity and trust of the PNT solution is of the utmost importance. For example, a simple delay in time of 1 millisecond or more can cause the navigation solution derived from an inertial navigation solution to diverge and provide incorrect position and velocity information. Likewise, the same millisecond (or even microsecond) inaccuracy in time can and will impact the integrity of a radar, EW, or SIGINT system. The need for resiliency is there. The need for a system that the warfighter can reliably trust is there. Through SOSA and FACE, Orolia provides a means for an Assured PNT that can protect, detect, and mitigate the impacts of emerging threats. Figure 1: The importance of integrity in Assured PNT With all military services actively focused on modernizing PNT and bringing the latest enhanced capabilities to the warfighter, vendors and government continue to align capabilities to include the integration of new technologies such as Military Code (M-Code) and advanced sensors to maintain trusted and Assured PNT data even in a GPS denied and/or threatened environment. The A-PNT solution must be layered. These PNT capabilities can be incorporated into an open standard architecture that allows for modular upgrades to any fielded platform. Alignment with an open standard makes this possible. Remaining agnostic to the platform allows for streamlined integration based on mission requirements. Figure 2: The layers of protection in a Resilient PNT solution The most versatile assured PNT card utilizes a layered approach. A timing reference with performance characteristics tailored to the system. A GPS or GNSS reference that can be hardened, easily updated, secure, and encrypted. An integrated sensor fusion platform capable of quick, seamless integration of new sensor and technologies to address emerging needs. An inertial measurement unit (IMU) that can provide high fidelity measurements in at least 6 degrees of freedom. Alternate assured PNT sources, such as odometry and RF signals, that are available and can be coupled and IMU and timing reference to provide reliable data even through GPS degraded and denied environments. A jamming and spoofing detection and mitigation platform, such as BroadShield, that provides integrity monitoring and statistical information both used in the sensor fusion platform as well as provided to other systems through a standard distribution interface. PNT distribution over a standardized data interface allowing for assured PNT distribution across cards. An A-PNT solution is backed by a solid foundation of sensors that play a large role in the performance of the navigation and timing solution. This solid foundation is built around two core competencies - timing and position. For timing, this can be an Oven Controlled Crystal Oscillator (OCXO) up to miniaturized rubidium oscillators (mRO) and chip scale atomic clocks (CSAC). There are trade-offs that should be considered by a system designer which will determine which timing reference to use. Two of these items, phase noise and stability, are important for different reasons. Phase Noise – Phase noise is the noise generated from the rapid, short-term fluctuations in the phase (frequency) of the timing reference. These fluctuations spread the power of the signal to adjacent frequencies, causing noise and interference. In systems where the frequency reference is used to send and receive signals, the impacts may be viewed as amplitude variations of received signals, channel interference, and random rotations of received signals. Phase noise is unavoidable, but the impacts of phase noise can be mitigated by choosing low phase noise timing references. Stability – Stability can be ability for the timing reference to transmit at the designated frequency for the entire life of the device without any deviation. Short-term stability, frequency accuracy, and aging are important for signal integrity and co-channel interference. In systems that require very accurate frequencies with little drift or accurate phase coherence may look for stable timing references. Phase Noise and stability are important criteria to take into consideration but not all timing references support both low phase noise and stability. To complicate matters, vibration and system dynamics will have a large impact on the performance specifications for both phase noise and stability. Each system design has different requirements and using a modular approach, the requirements can be met through a signal A-PNT form factor. Through using an open standard, the difficulties behind integrating different timing references are mitigated by common architectures and platforms that facilitate rapid development, testing, and deployment. For position and navigation, the absolute reference typically used is an IMU. These devices can be described as commercial (automotive), tactical, navigation, and strategic grade. Figure 3: IMU grade comparison (leveraging Petovello) These grades directly correlate to the performance specifications and errors inherent to the IMUs. Figure 4: Comparison of IMU technologies and grades (Passaro) The errors and specifications will have an impact on the drift of the IMU, the lower the bias and noise, the less the IMU will drift. However, there is a trade-off in size, weight and power and cost when using higher grade parts. Not all systems require higher grade, larger IMUs when the smaller IMUs are adequate for the mission. Figure 5: Comparison of IMU technologies and grades (Passaro) An IMU will impact navigation performance in GPS degraded and denied environments when the only sensor to rely on is an IMU. Thus, incorporating other sensors like barometers, alternative signals, and location references can provide high fidelity estimations of position, velocity, heading and orientation. Not all these sensors are available in different platforms, so ensuring a modular approach to the A-PNT solution allows for swapping out different sensors, fusion algorithms, and capabilities to meet the system needs. As technology advances, IMUs capabilities will increase. Systems will soon be able to utilize high performance gyroscope in a small form factor meant for modular form factors. A modular A-PNT solution is the difference between operating over seconds to minutes without GPS versus operating for hours without GPS. Inside the A-PNT solution lies an integrity checking and monitoring solution. Through tests in the lab and during other test event opportunities, interference detection and mitigation (IDM) software must be thoroughly updated to address the ever-present threats. Using updated IDM software, the A-PNT solution introduces dual purpose situationally aware sensor fusion platform and protected system driver for the important PNT data. At a top level, PNT distribution over the VICTORY Data Bus allows for accessibility and information distribution that is agnostic to any system. Taking advantage of an open system architecture allows for system integrators to design systems around performance specifications and mission requirements without the need to also modify system components outside of the PNT card. A multi-layered A-PNT approach is needed to (1) maintain and improve situational awareness, (2) enable GPS denied mission operations, and (3) keep our warfighters safe through threatened environments. A-PNT solutions address these challenges by providing encrypted GPS M-Code signals, multiple layers of protection, and unprecedented capability to defeat and function in the presence of Electronic Warfare (EW) threats. An A-PNT sensor card that adheres to an open standard tackles very important criteria for any system used by warfighters today: Military Off-The-Shelf components – Procurement and sustainability are addressed through use of off-the-shelf components. Flexibility, Scalability and Upgradability – The system is flexible, scalable, and upgradable to newer sensors and technologies with developer support. Ease of Use and Ease of Integration – Easy for the integrator and user to operate with familiarity. PNT subject matter expertise – Allows for integrity and trust of the technology as a system designed around an integrated PNT sensor core. Not all systems are the same. As emerging missions evolve, so must the technology that is relied on by the warfighter. Historically, this has not been an easy task. Modular Open System Architecture (MOSA) has provided a means to address the need for rapid development, test, and integration of new technologies for emerging missions. The benefit of this should not be understated. Rapid development and test leads to simplifying the procurement challenges that confront acquisition efforts. Leveraging the open standards in SOSA and FACE alongside simulation technologies allows the Air Force to be ready when needed. Section 2 - The impacts on culture and practices Organizational structure is very delicate detail. Bureaucracy exists in all large organizations. The most successful organizations are methodical in their approach towards achieving success. These approaches are typically unique to the business or organization as there is not a “one size-fit-all” solution. The impacts of the differences in cultures and practices between organizations can and does impact the timeliness and effectiveness of decisions being made. Altering culture and practices that prevent timely and effective decisions is difficult, but it starts by making open systems available to the Air Staff. In the ecosystem that provides warfighters with the latest and greatest technology, intellectual property is owned by the vendor. This is problematic when trying to develop, test, and field systems for the warfighter. Adopting open standards like SOSA and FACE reduce the restrictions that impact information flow between governing bodies and vendors. Intellectual property is owned by vendors. This makes it difficult for the same information to be shared between vendors, between governing bodies, and between vendors and governing bodies. The goal of SOSA and FACE is to not own the intellectual property of the vendor but to make the interfaces and modules, used by the proposed solution, widely available. In removing the intellectual property barrier and making the interfaces and modules widely available reduces another pain point in the development of products. With known requirements for interfaces and modules, time is not spent on making the design decisions but rather on the development, test, and integration of the solution. This allows for the air fighter to improve speed, quality of decision support, and achieve greater alignment among Air Staff. Orolia had the opportunity to participate in an Open Innovation Lab (OIL) Plugfest. A Plugfest is typically an event, based on a technical standard or system, where the designers of some technology (electrical equipment or software capabilities) test the interoperability of their products or designs with those of other manufacturers. The technical goal is twofold: check compliance to the standard and test the effectiveness of the standard. Besides helping the vendors improve their interoperability, Plugfests help create awareness about the standard and can improve transparency on compliance. These Plugfests can be formal, providing public test scores or informal and private. SOSA and FACE provide opportunities through Plugfests and technical exchange meetings for vendors and government to not only stay informed of compliance and alignment success but also collaborate and innovate. Such opportunities are only made possible through the application of open standards and modular frameworks. During the OIL Plugfest, multiple vendors were asked to provide CMOSS, and SOSA aligned products to integrate alongside other cards and chassis. Years ago, such an event could not exist due to vendor restrictions. Open standards reduced the overhead requirements of designing the electrical and mechanical interface, understanding the software modules, and deciding on the form factor that would be implemented. In as little as 6 weeks, Orolia adapted a boxed based A-PNT solution to a card based A-PNT solution that was plug-in compatible with the system. Systems that adopt the Modular Open System Architecture (MOSA) provided by SOSA, CMOSS and FACE have proven to be modular, easily accessible, and easy to integrate. The end goal of any business or organization may not change, but the methods that may be employed must often adapt. Adaptation does not come easy but is necessary for constant improvement. Section 3 - Addressing long-term strategic competition MOSA is meant to enhance the department’s ability to modify weapon systems effectively. Modularization simplifies system design by making complexity manageable, enables programs to conduct parallel development efforts, and accommodates future uncertainty by allowing incremental changes to a system. A statement from the Summary of the 2018 National Defense Strategy: “A long-term strategic competition requires the seamless integration of multiple elements of national power – diplomacy, information, economics, finance, intelligence, law enforcement, and military. More than any other nation, America can expand the competitive space, seizing the initiative to challenge our competitors where we possess advantages, and they lack strength. A more lethal force, strong alliances and partnerships, American technological innovation, and a culture of performance will generate decisive and sustained U.S. military advantages.” Key edicts from the national defense strategy that can prove paramount to warfighter success. Open standards are a key differentiating factor that benefit both industry and government. As the needs of the warfighter continues to expand, technological capabilities employed by the warfighter must also continue to expand. Be strategically predictable, but operationally unpredictable . Adopting an open standard in SOSA and FACE provides the means to innovate and bring about new technologies. These technologies, either being improvements upon existing technologies or completely new technologies, will allow the warfighter to address this mission critical piece to competitiveness. Frustrating their efforts . Assured PNT is the backbone of any mission critical system. Knowledge of position and time will impact the functionality of any system. As such, position and time are very critical, and very susceptible components to a system designer or integrator. Competitors are aware of such a bottle neck and will try to disrupt these capabilities through this point of weakness. The need to protect, detect, and mitigate against such threats emerges every day. The need to rapidly address, innovate, and deploy the new technologies should not be slowed by proprietary interfaces, communication protocols, and process. Open System Architectures provide a means to counteract and even accelerate development and procurement to ensure success. Integrate with U.S. interagency . This edict expands to all aspects of U.S. interagency, including applying internally as well. The need to identify and build partnerships amongst military entities is an absolute requirement to address areas of economic, technological, and informational vulnerabilities. Such a task must not be hindered by the development or acquisition of systems caused by lack of information sharing and lack of common architectures. The deployment of common platforms, supported by MOSA, facilitates this agenda. Foster a competitive mindset . To succeed, new technologies must be robust and resilient. The key is to out-think, out-maneuver, and out-innovate the competitors. The use of resources to verify compliance and credibility is paramount to ensure any newly developed technology is deployable. New technologies can be developed using simulated environments without the overhead of working through proprietary methods which inevitably delays the development process and loses the competitive advantage. Using internal testing and hardware-in-the-loop capabilities that can emulate real world threats, developers and integrators can take that next step to developing resilient and assured capabilities. GPS simulators, either used on mobile test platforms or coupled with hardware-in-the-loop capabilities to simulate inertial movement, can shorten the development and testing that would be required for final integration. An evolving technological capability is an absolute requirement. Minimal impact to system interoperability is a key goal to ensuring that the edicts mentioned above are achieved. By allowing for modular open system architectures, rapid improvements can be made to A-PNT cards that include: Encryption – Layering and improving encryption methodologies (such as upgrading receivers in the field), it would be possible to harden GPS. A robust PNT ecosystem allows for a unified effort to improve encryption through affordable solutions. Threat Detection and Mitigation – Various algorithms can drive and improve filtering and help operators detect potentially malicious interference in navigation and timing systems. Through modular software components and hardware architectures, updating threat detection and mitigation capabilities using algorithms and layered PNT remains seamless. As new threats emerge, protecting the A-PNT through on-board interference detection and mitigation algorithms is a need. Improved signal processing – Emerging tools on the consumer side have improved the ability to process radio frequency signals. The NATO Research and Technology Organization points to improved signal processing as one of several key measures needed “to boost the resistance of GPS to [adversarial] jamming technologies.” High-end simulators can help the military to test such capabilities and get them into the field more quickly. Improved signal processing could also support more robust uses of PNT data leading to more effective systems. Higher receiver bandwidth, more accurate position and navigation, and phase coherent timing solutions are all results of the improved signal processing. Using analytics and modeling and simulation analyses, continuous testing can be performed to challenge the current systems and the potential to create new requirements to provide the correct PNT information. Advanced antennas – An advanced antenna creates focused beams and antenna patterns, focusing on where the satellites are and avoiding any potential interference. Strategically predictable yet unpredictable with the ability to adapt quickly. A high-level view of this approach and the different PNT information opportunities can be found in Figure 6: Figure 6: Available assured sensors for more robust solutions Each individual item adds a unique solution that is incorporated into the PNT solution provided by an A-PNT card. With opportunities to use these sensors, the ability to adapt, foster competition, and frustrate the competition is easier to achieve. While not all sensors may be available all the time, having choices allows for an adaptable solution that remains unpredictable and fosters interagency communication. Finally, the use of GPS simulators and other various test events drive collaboration among government and vendors alike. The Air Force must take advantage of operational tests that exercise the new technologies. With modular technologies and open, available standards that vendors have access to, the Air Force can quickly test these new technologies, fostering not only an atmosphere of collaboration but competitiveness as well. Section 4 - Preparing for the future starts now The goal is for any leveraged system to be the state of the art. Integration of the newest sensor and system technology, the highest operational performance, and the advancement of software design and implementation are of the utmost importance. These goals are shared both by vendors and government alike. Despite the common goal set, the approach has been different. As each approach is different, systems today result in tightly coupled integration without portability and flexibility. State of the art at the cost of flexibility decelerates the transition from the force that exists today to the Air Force the nation needs. To achieve technological preparedness, the groundwork must be laid now. Adopting a common framework through open standards is a means to do so. Utilizing a standard reference architecture helps remove the barriers prohibiting modularity, portability, and interoperability. Modularity . Software and sensor components drive the capability of the system. Vendor specific software leads to tightly coupled integration which prohibits the modularity of the software and system. The hardware modules must be decoupled from the software components such that software components and hardware modules can be developed and tested independently. This independence cuts down on development time and promotes the development of test tools that can be further leveraged to verify compliance and compatibility. VICTORY, as an example, promotes a standardized software interface. Along with a test tool and standards body, conformance and capability can be tested and verified without the need for specific hardware implementations. This allows developers to continue addressing near term implementation goals without relying on supply chain management or other roadblocks. Portability . Sensor components found in fielded systems are the backbone of the system functionality. These items must be easily replaced and updated to sustain and increase system performance. The same is applied to software components developed for systems and solutions. The need to port existing software solutions to newer processors or platforms will assist in reducing the impacts of supply chain or procurement initiatives. The adoption and implementation of open standards leads to portability between platforms. Ease of portability allows for integrators and decision makers to address emerging needs with resilient, tested, and trusted solutions. As an example, the Orolia C-PNT solution has been ported to multiple different platforms and iterations. The software is built to remain agnostic to sensors such that the inclusion of VICTORY, SOSA, CMOSS and FACE allow for easy portability to more available processors. Interoperability . Communication between components and modules is important for any functioning system. Plugfest opportunities help test the compliance, the interoperability, and performance of newly designed systems. Such events may only exist due in part to the adoption of MOSA and standards that are managed and agreed upon. As open standards bodies, SOSA and FACE host opportunities for vendors and government to test this interoperability. A key importance of interoperability is found in the ease of replacing technologies as well as updating technologies. For example, if the need arises to swap out an inoperable sensor or the need to update a sensor itself with a newer version, the interoperability of the sensor card is important to reduce integration and development time. Take, for example, the Modular Open RF Architecture established through SOSA. Figure 7: The MORA topology The VICTORY Position Navigation and Timing (PNT) is abstracted from the system software component types such that an end user can address and update components through a common standard data bus. The only limitation for an A-PNT solution to be updated or upgraded is the adherence to an established standard in VICTORY. With the communication and component level standardized, the three key aspects of modularity, portability and interoperability can easily be addressed with no impact on other devices or components of the system. The importance of removing these barriers allows for the Air Force to transition to the next level and take advantage of the state-of-the-art technologies. Removing the focus on integration and development and spending more time focusing on the strategic targets allows for success and safety of the warfighter. Giving the Air Force more time to address the areas of need allow for greater attention to be paid to the near term and long-term strategic mission. Evaluating acceptable levels of risk to mission, force and security is paramount to the success of any organization. Leveraging open system architectures and standards remains beneficial to this end goal. Conclusion Modernized systems require modernized technology. As the emerging needs grow and evolve, the technology needs to advance with it. As a mission critical piece to any modernized system, assured position, navigation, and timing technology cannot be hindered by tightly locked solutions that do not allow for modularity and growth. The capabilities must rapidly and effectively evolve. The adoption of open standards is a unified approach to addressing the needs of the air fighter today and for the future. To rapidly evolve, designers should not be burdened by lack of modularity, interoperability, or information flow. To effectively evolve, decision makers should not be burdened by information flow and process which detracts from more focus on planning and strategy. Promoting the collaboration between industry, academia and government will allow the Air Force to overcome any technical challenge. Such a change in culture and process can be facilitated through the adoption of open standards. They allow us to go fast, be effective, and most importantly, be successful. References ( Please note that the links below are good at the time of writing but cannot be guaranteed for the future .) Modular Open Systems Approach (MOSA) Reference Frameworks in Defense Acquisition Programs, published by the Office of the Under Secretary of Defense for Research and Engineering, Director of Defense Research and Engineering for Advanced Capabilities, May 2020, refer to: https://ac.cto.mil/wp-content/uploads/2020/06/MOSA-Ref-Frame-May2020.pdf Summary of the 2018 National Defense Strategy of The United States, authored by Jim Mattis, refer to: https://dod.defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf FACE™ Technical Standard, Edition 3.1 (C207), published by The Open Group, July 2020; refer to: www.opengroup.org/library/c207 Technical Standard for SOSA™ Reference Architecture, Edition 1.0 (C212), published by The Open Group, September 2021; refer to: www.opengroup.org/library/c212 Gyroscope Technology and Applications: A Review of the Industrial Perspective, authored by Passaro, Cuccovillo, Valani, De Carlo, and Campanella. Methods for Accuracy Verification of Positioning Module authored by Patric Jansson Beyond GPS: A Multilayered Approach to Addressing PNT Vulnerabilities, authored by Adam Stone, refer to: https://www.orolia.com/beyond-gps-a-multilayered-approach-to-addressing-pnt-vulnerabilities/ Real-Time Integration of a Tactical-Grade IMU and GPS for High-Accuracy Positioning and Navigation, authored by Mark G. Petovello. About the Author Brent Abbott is an R&D technical lead and manager for Orolia Defense & Security, a leader in Assured Position, Navigation, and Timing products. He has a Bachelor’s and Master’s in Signal Processing and has worked in the DoD space for more than 13 years. He constantly seeks to promote the advancement of technology as seen through several PNT related patents, publications, and presentations. About The Open Group FACE™ Consortium The Open Group Future Airborne Capability Environment™ (FACE) Consortium, was formed as a government and industry partnership to define an open avionics environment for all military airborne platform types. Today, it is an aviation-focused professional group made up of industry suppliers, customers, academia, and users. The FACE Consortium provides a vendor-neutral forum for industry and government to work together to develop and consolidate the open standards, best practices, guidance documents, and business strategy necessary for acquisition of affordable software systems that promote innovation and rapid integration of portable capabilities across global defense programs. Further information on the FACE Consortium is available at www.opengroup.org/face . About The Open Group SOSA™ Consortium The Open Group SOSA™ Consortium enables government and industry to collaboratively develop open standards and best practices to enable, enhance, and accelerate the deployment of affordable, capable, interoperable sensor systems. The SOSA Consortium is creating open system reference architectures applicable to military and commercial sensor systems and a business model that balances stakeholder interests. The architectures employ modular design and use widely supported, consensus-based, non-proprietary standards for key interfaces. Further information on the SOSA Consortium is available at www.opengroup.org/sosa . About The Open Group The Open Group is a global consortium that enables the achievement of business objectives through technology standards. With more than 870 member organizations, we have a diverse membership that spans all sectors of the technology community – customers, systems and solutions suppliers, tool vendors, integrators, and consultants, as well as academics and researchers. The mission of The Open Group is to drive the creation of Boundaryless Information Flow™ achieved by: Working with customers to capture, understand, and address current and emerging requirements, establish policies, and share best practices. Working with suppliers, consortia, and standards bodies to develop consensus and facilitate interoperability, to evolve and integrate specifications and open-source technologies. Offering a comprehensive set of services to enhance the operational efficiency of consortia. Developing and operating the industry’s premier certification service and encouraging procurement of certified products. Further information on The Open Group is available at www.opengroup.org . DOWNLOAD PDF

GPS jamming and spoofing attacks pose a great risk to vessels at sea, causing them to drift into hostile waters unknowingly. A solution is here and available today, ready to defend and protect. Home • PNT Library • How to Defend Against Interference at Sea How to Defend Against Interference at Sea DOWNLOAD PDF By Safran Federal Systems DOWNLOAD PDF

Impact of Temperature and High Vibration in Ground, Shipboard and Aircraft Platforms on GPS-disciplined, Low Phase Noise, Time and Frequency References. Home • PNT Library • ION Joint Navigation Conference 2019 Abstract ION Joint Navigation Conference 2019 Abstract DOWNLOAD PDF By Timothy Tetreault DOWNLOAD PDF

Synchronizing time to coordinate critical operations isn’t just a challenge—it’s essential in today’s high‑stakes environments. Explore NTP & PTP key differences. Home • PNT Library • NTP vs PTP Choosing the Right Time Sync Solution NTP vs PTP Choosing the Right Time Sync Solution DOWNLOAD PDF By Kevin Stottler How Modern Devices Keep Perfect Timing: Understanding NTP and PTP Synchronization With the increasing connectivity of everyday devices such as phones, cars, and televisions, manually setting clocks is becoming a thing of the past. Have you ever wondered how this technology works? This post will explain and compare Network Time Protocol and Precision Time Protocol, two methods for automatically synchronizing devices over IP networks, and provide some historical context. Carrying out activities at coordinated times applies to activities as simple as meeting a friend for coffee or as complex as military operations. In earlier decades, radio systems like NIST’s WWVB broadcast were used, phone modems dialed time references, and clocks were set by hand. As computer networks grew to hundreds or thousands of nodes, it became less practical for each node to use one of these methods. This historical context is crucial to understanding the evolution of time synchronization methods. What is Network Time Protocol (NTP)? How it Works and When It’s Accurate Enough The development of the Network Time Protocol solved this problem. In a network with a thousand nodes, only a few now had to synchronize themselves directly to primary references such as radio broadcasts, satellites, or atomic clocks. NTP is hierarchical, with servers connected to primary references considered “Stratum 1.” Additional servers can synchronize with Stratum 1 servers, becoming Stratum 2, and so on. This allows more capacity to be added and the network to scale up without adding more satellite receivers or atomic clocks. Some networks also use Anycast, which directs traffic to the nearest server, or Round Robin or pooling, where DNS is used to direct clients to one of many servers. These methods distribute requests evenly among a group of servers to balance load or provide redundancy. Like many other protocols, NTP works by a client sending a request to a server and receiving a response. With NTP, the client keeps track of the time at which the request was sent (t1), the server responds with the times the request was received (t2), and the reply sent (t3) to account for processing time. The client records when the response is received (t4). Using these four timestamps, the client can estimate how long the response took from the server (path delay) and calculate the difference between its own clock and the server’s. Without this delay compensation mechanism, the client’s clock would be offset by the path delay, which can be around 50ms on the Internet. This relatively simple technique, requiring only software on most nodes, can often synchronize machines to within 10ms over the Internet, and within 1ms over local networks where routing is more predictable. The primary source of error is if the delay is not symmetrical, such as on congested networks. However, this technique is plenty accurate enough for many use cases, such as timestamping log events or messages. Public vs. Private NTP Servers: Should You Rely on Public NTP Servers? There are many public servers on the Internet that can provide accurate time for free, operated by various software vendors, telecom providers, universities, and governments. This is usually fine for synchronizing workstations. However, these services are not guaranteed, and network conditions outside local control may affect accuracy or availability. Consider deploying a dedicated local NTP server such as the Safran SecureSync to provide resilient network synchronization for use cases needing greater accuracy, availability, or control. What is Precision Time Protocol (PTP)? High Accuracy Time Sync for Critical Systems For many general use cases, NTP is plenty accurate and cost-effective. For synchronizing humans, NTP works well. However, if you’re synchronizing machines, especially fast-moving ones, you may need the Precision Time Protocol (PTP). Precision Time Protocol (PTP) is defined in IEEE 1588 and is designed to enable tighter synchronization within a local network. PTP can usually synchronize two nodes to within microseconds, and with hardware timestamping, even sub-microsecond accuracy is possible. These are orders of magnitude better than NTP. The trade-off is greater complexity and cost to implement. There are no public servers like with NTP, so each network requires its own grandmaster to be configured at the top of the hierarchy. How PTP works: Sync Messages, Hardware Timestamps, and Network Aware Devices The protocol functions very similarly to NTP, with the timeTransmitter and timeReceiver nodes exchanging messages to calculate both the network delay and the offset of their clocks. However, the timeTransmitter initiates the exchange by sending a sync message, often as a multicast to all timeReceivers. Network interfaces designed to support PTP are also capable of hardware timestamping, recording the time when a packet is received or sent on the wire rather than relying on the operating system. Another significant difference is the behavior of the protocol when traversing routers or switches. In a PTP network, most intermediate devices like routers and switches must be PTP-aware. They should account for queuing or processing delays in passing PTP messages. These devices, referred to as either boundary clocks or transparent clocks, play a vital role in the seamless operation of the PTP network. Transparent clocks update the timestamps in the PTP messages and “transparently” pass them along. Boundary clocks act as timeReceivers to upstream devices and then act as timeTransmitters to downstream devices. Sectors where PTP is common are generally those where specialized networks are used, and increased accuracy is required. This includes telecom and other utilities, such as coordinating cellular handoffs or grid switching, high-frequency trading, and industrial automation, to ensure that separate machines can make coordinated movements. Safran offers several products, including SecureSync , that can provide PTP time, NTP and other outputs such as IRIG. For enhanced resilience, M-Code can be supported. PTP vs NTP: Key Differences in Accuracy, Use Cases, Complexity, and Cost Example Use Cases Choosing Between NTP and PTP: What’s Right for Your Application? The problem of synchronizing time to coordinate action is not just an old one, but a crucial one in our modern interconnected world. NTP and PTP, two common approaches, play a significant role in solving this problem. While NTP can synchronize humans, PTP is often needed to synchronize machines. The trade-off for the higher performance of PTP is its increased cost and complexity. Beyond PTP, a technology called White Rabbit is capable of nanosecond-level synchronization but requires dedicated hardware and infrastructure. Poor time synchronization can lead to out-of-order actions or event logs when designing a system, which can be challenging to troubleshoot. However, by considering this need earlier in the design process, scheduled tasks execute at the correct time, and logs reflect the actual time of events. This proactive approach can significantly enhance the efficiency of your system. Talk to us about NTP or PTP for your application by emailing sales@safranfs.com or filling out our inquiry form here . DOWNLOAD PDF

The interference threat information provided from a Controlled Reception Pattern Antenna (CRPA) combined with reliable PNT sources, such as the Safran VersaPNT and Geonyx systems, can deliver situational awareness information, such as the approximate position of interference threat sources. Home • PNT Library • Interference Threat Position Awareness Interference Threat Position Awareness DOWNLOAD PDF By Garrett Payne and Dylan Dayton Real-time interference detection for Situational Awareness (SA) The interference threat information provided from a Controlled Reception Pattern Antenna (CRPA) combined with reliable PNT sources, such as the Safran VersaPNT and Geonyx systems, can deliver situational awareness information, such as the approximate position of interference threat sources. A CRPA was integrated with a Geonyx system and tested operationally.. The CRPA, combined with the accurate heading of the Geonyx, proved to provide robust threat direction finding abilities. Technology Used CRPA Antenna A CRPA is a type of antenna system featuring multiple antenna elements designed to enhance the resilience and performance of Global Positioning System (GPS) receivers by mitigating interference VersaPNT The VersaPNT is a robust Position, Navigation, and Timing (PNT) solution and can be configured to use external PNT sensors and devices which include but are not limited to a CRPA. Geonyx The Geonyx is a land true-inertial navigation, target geolocation & artillery pointing system. CRPA Interface The interference direction-finding system utilized a Novatel GAJT-710 (7-element CRPA) for detecting interference and providing information on detected signals. The GAJT-710 provides interference detection on both GPS L1 and L2 bands and can detect up to 6 simultaneous threats per band. The system parsed the data feed from the CRPA to get information of detected interference and calculate relative directions to suspected threat emitters. Geonyx Interface The interference direction-finding system utilized a Geonyx system for providing position and heading data for absolute positioning. The VersaPNT has also been used to provide position and heading data, similar to the Geonyx. With knowledge of the absolute position and heading of the system, the absolute direction to detected interference can be calculated. The CRPA provides interference relative to antenna heading. Assuming the pointing angle between the CRPA and the Geonyx is known, the relative angles of interference can be converted to absolute angles. GUI Creation and Use The prototype UI shows the threat information detected from the CRPA in real time: • Signal strength, azimuth angle, and elevation angles are shown for detected threats on L1 and L2 bands. • Lines of bearing are calculated using the absolute position and heading from the Geonyx and can be shown on a map. Future Work The prototype ran on separate hardware, so the next step of integration will be to integrate directly on existing navigation/timing systems. Systems will directly intake the CRPA feed and use internal position and heading for calculating absolute bearing to threats. Threat lines of bearing will be shown on system WebUI and updated in real time. Algorithms will be developed and refined for calculating the absolute position of threats based upon lines of bearing. With enough system movement, the changes in lines of bearing over time can be used to detect the position of threat emitters. DOWNLOAD PDF

More space missions are taking place in Lower Earth Orbit (LEO). Newer, more advanced receivers are needed to have sufficient PNT capabilities. Doppler shifts experienced on these missions will be high, however, robust testing to ensure mission success is achievable... Home • PNT Library • Doppler Effects on Spaceborne PNT Applications Doppler Effects on Spaceborne PNT Applications DOWNLOAD PDF By Joshua Prentice Since the very first space missions positioning, navigation, and timing (PNT) have been crucial for spaceborne applications. Traditionally, space vehicle PNT has been achieved through various combinations of ground stations, optical navigation, onboard high-precision clocks, inertial measurement units, and other methods. Only recently, however, has existing global navigation satellite systems (GNSS) been added to that list. GNSS constellations were designed to provide PNT for Earth-borne applications taking place on the ground, sea, or in the atmosphere. As such, those GNSS waveforms are primarily aimed toward the Earth, but there is a small amount of spill-over of the main lobe beyond the silhouette of Earth and into space. Additionally, the side lobes of most GNSS waveforms are also broadcast into space beyond Earth. Because these signals are visible from orbit, they can conceivably be used for the PNT of space vehicles. In terms of spaceborne navigation from GNSS constellations, there are generally two main orbital regions of concern. Altitudes between Earth and the GNSS altitude, known as being under the “canopy”, and altitudes above the GNSS canopy as shown below in Figure 1. Figure 1: Below and Above the GNSS Canopy When orbiting the Earth underneath the GNSS canopy the receiver antenna must point “skyward” towards the GNSS constellations. This scenario is more closely related to traditional GNSS navigation, although satellites will rise and set more frequently. The full spectrum of these signals is available with the advantage of stronger signal strength compared to surface and low-atmospheric operations. In scenarios where the receiver vehicle is orbiting above the GNSS canopy, navigating based on GNSS constellations becomes much more difficult as the only available portions of the waveform are the main lobe spill-over and the side lobes. For simplification and to limit the scope of this tech brief, the primary area of concern will be space vehicles in geocentric orbits beneath the GNSS canopy. When navigating from GNSS signals Doppler shift is always present no matter how close to the GNSS canopy the receiver is. However, when the navigating receiver is traveling at velocities necessary to maintain a stable orbit, the Doppler shift is much greater. Figure 2: Doppler shift diagram The Doppler shift change in frequency can be expressed as (Parker, 2017): In equation (1) 𝑓₀ is the source carrier frequency, Δ𝑣 is the relative velocity of the space vehicles, and 𝑐₀ is the speed of light. This equation does not account for ionospheric and tropospheric effects encountered when GNSS signals pass through the Earth’s atmosphere. When considering equation (1) for multiple scenarios and orbital altitudes, the speed of light is a constant, and depending on the GNSS constellation being used so is the source carrier frequency. Thus, the biggest factor affecting Doppler shift is the relative velocity of the space vehicles. Because the satellites that make up GNSS constellations are held to very strict orbits with known orbital velocities and those orbits are maintained throughout the lifetime of the constellation, the determining factor of the relative velocity for any given mission is the orbital velocity of the receiver vehicle. It follows that the goal in computing a theoretical maximum Doppler shift a spaceborne receiver may encounter is to maximize the relative velocity between the receiver vehicle and the GNSS vehicle. A scenario that would accomplish this would be a receiver vehicle in very low earth orbit (VLEO) tracking GNSS signals. Spaceborne missions taking place in LEO are a unique case of GNSS PNT due to the high relative velocity compared to the GNSS constellation vehicles while still being beneath the GNSS canopy. The dynamics of such a scenario are some of the highest that a receiver may experience during typical PNT operations. As such, the Doppler search space of receivers deployed in LEO must be much wider than needed for ground, sea, and airborne missions. One example of a very low earth orbit mission (VLEO) is the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE). The GOCE mission required extremely precise orbit determination to carry out its scientific objective of mapping Earth’s gravity field to an accuracy of 1-2 cm. The GOCE space vehicle maintained an average orbital altitude of 255 km, placing the average orbital velocity around 8 ᵏᵐ⁄ₛ (European Space Agency, 2022). The GOCE mission tracked GPS signals to assist in orbit determination. GPS satellites orbit at an altitude of 20,200 km with an average orbital velocity of roughly 4 ᵏᵐ⁄ₛ (US Space Force, 2022). Figure 3: GOCE Missions in VLEO have much shorter durations than other spaceborne missions due to the need for constant orbital maintenance maneuvers to counteract the atmospheric drag, and as such, it can be considered the lower limit of possible orbital altitudes. To estimate a maximum possible Doppler shift the worst possible case scenario would be the receiver satellite travelling in exactly the opposite direction (±180°) of the GNSS vehicle. While this is generally a very rare situation some space vehicles do travel in non-standard orbits, so it is possible. Thus, the relative velocity of the space vehicles can be expressed as: Where: So that: Note that all velocities are expressed as linear for simplification. With an established relative velocity, the maximum estimated Doppler shift can be calculated using the following values: Calculating the Doppler shift using the equation (1) results in: With a worst-case-scenario Doppler shift of 63 kHz, it is imperative to ensure the receiver being placed into orbit can perform under such conditions. Skydel Simulation Engine of the BroadSim product line is capable of simulating spaceborne scenarios, even under conditions where Doppler shift is maximized. One of the default vehicle profiles within Skydel is an Earth-orbiting spacecraft with highly customizable Keplerian elements to define the exact orbit thereceiver vehicle will experience. Should the default spacecraft profile not provide enough customization, Skydel can also be interfaced through hardware in the loop (HIL) where exact positions are pushed to the simulator to simulate the specific trajectory of a receiver vehicle. Unlike some simulators where the Doppler shift will have to be either predetermined or manually added to the scenario, Skydel handles Doppler, ionospheric, and tropospheric effects automatically based on the scenario without requiring user input. Figure 4: Skydel Screenshot LEO and VLEO missions are becoming more and more popular especially in the fields of PNT, from both from a provider and user standpoint. To make sure those missions will have sufficient PNT capabilities advanced receivers will need to be used and new receivers will be developed to fill specific roles and advance current capabilities. While the Doppler shifts experienced by receivers on these missions will be high, robust testing to ensure mission success is capable using BroadSim simulation products powered by Skydel. Commonly Asked Questions About Doppler Effects Why are GNSS signals now being used for space navigation? Historically, space vehicles relied on methods like ground stations, inertial sensors, and onboard clocks for navigation. GNSS was originally designed for Earth-based applications, but signal spillover (main lobe and side lobes) into space now allows satellites to use GNSS for autonomous navigation. Why is this topic important? Reliable, autonomous PNT in space is critical for military satellites, ISR platforms, and scientific missions, especially when access to ground-based navigation aids is unavailable or denied. What causes Doppler shift in spaceborne GNSS reception? The Doppler shift arises from the relative velocity between the receiver spacecraft and the GNSS satellite. The faster the receiver moves in orbit, the more pronounced the frequency shift in received GNSS signals. References European Space Agency. (2022). GOCE Facts and Figures. Retrieved from https://www.esa.int/Applications/Observing_the_Earth/FutureEO/GOCE/Facts_and_figures Parker, M. (2017). Digital Signal Processing 101. Elsevier Inc. US Space Force. (2022). GPS: The Global Positioning System. Retrieved from https://www.gps.gov/systems/gps/space/#orbits DOWNLOAD PDF