The SEL-2488 satellite-synchronized network clock. Photo: SEL
SEL has released a new network clock designed for critical infrastructure and harsh environments. Model SEL-2488 receives GNSS time signals and distributes precise time via multiple output protocols, including IRIG-B and NTP.
The SEL-2488 provides time-delay compensation for antenna cables and output cables on per-port basis to further optimize time distribution accuracy. For security, the clock features the Syslog Ethernet standard for event messaging, role-based accounts and LDAP for user authentication, and secure HTTPS web interface.
The clock synchronizes with precise time accuracy to within ±40 nanoseconds to UTC for power protection applications. The standard TCXO holdover accuracy is 36 µs/day and the optional OCXO holdover accuracy is5 μs/day.
Time can be distributed from eight time outputs configurable for IRIG-B or time pulse outputs. The SEL-2488 also includes four standard Ethernet ports, which provide NTPv4 and are available in copper as well as single- or multimode fiber.
With Satellite Signal Verification, the SEL-2488 uses signals from a second satellite constellation to validate the GPS time signals, providing a layer of protection from GPS spoofing attacks. The SEL-2488 also provides an option for a second, redundant power supply and operates in a temperature range of –40° to +85°C (–40° to +185°F).
The SEL-2488 supports DHCP with a captive portal, LDAP, an HTTPS device webpage, and acSELerator QuickSet SEL-5030 software for easy and secure configuration.
Abstract submissions are now being accepted for The Institute of Navigation’s (ION) Pacific PNT Conference, to be held April 20-23, 2015, at the Waikiki Beach Marriott, Honolulu, Hawaii. Abstracts are due November 14, 2014.
Pacific PNT, where “East Meets West in the Global Cooperative Development of Positioning, Navigation and Timing Technology,” brings together policy and technical leaders from Japan, Singapore, China, South Korea, Australia, the United States, and more for policy updates, program status and technical exchange.
“Global cooperative interoperability” will frame the technical program. Leaders representing academia, government, industry and the scientific community will convene to solve PNT challenges that impact Pacific Rim development.
Pacific PNT 2015 is organized by a Pacific Rim advisory board and will feature technical papers presented on a diverse array of topics including:
Aircraft Navigation and Surveillance
Agricultural, Construction and Mining
Algorithms and Methods
Alternative Navigation and Signals of Opportunity
Aviation Applications of GNSS
Challenging Navigation Problems
Collaborative Navigation Topics
Earthquake & Tsunami Prediction and Monitoring with GNSS
GNSS Augmentations
GNSS Correction and Monitoring Networks
GNSS Environmental Monitoring
GNSS Policy/Status Updates
GNSS Signal Structures
Inertial Navigation Technology and Applications
Interference and Spectrum
Ionosphere Monitoring with GNSS
Magnetic Field Navigation and Mapping
Maritime Navigation
Nature-Inspired Navigation
PNT and Automobile Safety
PNT and Social Media
PNT for Domestic and Healthcare Applications
Precision Agriculture and Machine Control
Time and Frequency Distribution
UAS Technologies
Abstracts are being accepted through November 14, 2014. For more information the ION’s Pacific PNT 2015, visit www.ion.org/pnt.
PTTI 2014 Registration Opens
Registration is now open for the ION Precise Time & Time Interval Meeting (PTTI) 2014 to be held December 1-4 at the Seaport Boston Hotel, Boston, Massachusetts. The technical program is available online.
The annual PTTI conference has a technical program designed to disseminate and coordinate PTTI information at the user level; review present and future PTTI requirements; inform government and industry engineers, technicians, and managers of precise time and frequency technology and its problems; and provide an opportunity for an active exchange of new technology associated with PTTI.
The Distinguished PTTI Service Award, which recognizes outstanding contributions related to the management of PTTI systems, will be presented on Thursday, December 4.
Mitre’s new Time Anomaly Detection Appliqué (TADA) protects modern digital systems from spoofing attacks that can corrupt time source signals.
Successful spoofing attacks could result in navigational systems going haywire and grounding airplanes, jumbling of buying and selling orders, a shutdown of the stock market, or power-grid failures. Infrastructure and defense systems often rely on GPS’s unencrypted position, navigation, and timing (PNT) signal as their source of accurate time, accurate to about 14 nanoseconds.
The TADA system detects and, for certain users, mitigates timing attacks. “Almost every system has a need for precise and accurate time,” said Darrow Leibner, the Mitre TADA project lead. “Because GPS is accurate and ubiquitous, users have gotten away from implementing other time-keeping methods. That’s where the potential vulnerability comes in.”
TADA is designed to provide a cost-effective, reliable, and easy-to-use method for protecting GPS receivers against spoofing attacks. The system defends against spoofing by continuously comparing a trusted input, such as a known frequency or location, with those provided by the GPS receiver. When a difference between these two inputs is detected, TADA alerts the user to the suspected PNT anomaly.
For a trusted input, TADA uses an atomic clock frequency. For each second measured by the incoming GPS timing signal, TADA counts the number of frequency cycles generated by a Cesium clock. If the incoming GPS signal is valid, TADA will count exactly the expected number of Cesium frequency cycles. If TADA measures a higher or lower number of timing signals than expected, it will display the difference. A difference outside the acceptable margin of error will prompt TADA to alert its users that the GPS timing signal is possibly being spoofed.
In the same way it uses a trusted time source, TADA can also use a known location to detect a spoofing attack. To do this, the user inputs the location of a GPS receiver antenna into TADA. TADA monitors the reported position for any changes. Any reported change of the stationary location would most likely be due to spoofing attack and prompt an alert to the user. Once alerted by TADA to a spoofing attack, users can quickly switch to existing backup systems.
“This is not the invention of the lightbulb,” Leibner said. “Rather, it’s a clever use of existing technologies packaged in such a way that users obtain a greatly increased level of protection for a minimum of investment. None of the TADA components on their own are brilliant. But as one manufacturer said after seeing a detailed description of TADA, ‘It’s brilliantly simplistic.’”
The next stage in TADA’s development is to provide it with the capability to not only detect spoofing attacks, but to mitigate its effects and pinpoint their origin. Mitre will also continue to advocate that to bolster the nation’s infrastructure defenses against spoofing, TADA-like monitoring techniques be included within commercial product design.
Spectracom, a business of the Orolia Group, has extended its global service capability through a partnership with EZU Technologies. Joining Spectracom service centers in North America and Europe, EZU Technologies will support Spectracom users throughout the Asia-Pacific region from its facility in Hong Kong. Initially, services will include equipment calibration and repair services. Over time, more capability will be added to deliver Spectracom’s full range of services in the region.
Spectracom’s portfolio of GNSS signal management solutions include a variety of services to ensure their customers gets the most out of their application for positioning, navigation and timing. “We understand our customer’s needs for fast access to services. Our strong growth in Asia, particularly for GNSS simulation and enterprise-class timing, will be supported by localizing services in the region,” said Thierry Delhomme, general manager, Spectracom Europe.
This new service center is the first of several partnerships to deliver global services in support of Spectracom solutions. Lisa Withers, Spectracom President and CEO, said, “We are pleased to expand our existing partnership with EZU Technologies to develop a regional service hub. This will enhance the local service provided by our strong set of local distributors and resell partners throughout the region.”
Anritsu Company is launching an internal atomic clock option for its MS2720T Spectrum Master handheld spectrum analyzer that allows users to acquire excellent frequency accuracy, including in environments in which the GPS cannot be used.
Integrating the atomic clock inside the MS2720T provides field engineers and technicians with a durable, handheld spectrum analyzer that can deliver the extremely high accuracy necessary to prove regulatory compliance.
By using the atomic clock, users can acquire a very accurate frequency reference without the need of the GPS. Calibration accuracy of the atomic clock is 1×10-9. The MS2720T can be configured with the GPS receiver and the atomic clock to achieve both high-frequency accuracy and GPS location stamping of measurements.
Because the atomic clock module mounts inside the instrument, there are no loose cables that can potentially snag on branches, antennas or other extensions prevalent in the field environments in which the MS2720T is used, the company said. The atomic clock is automatically used once it is installed.
The Spectrum Master MS2720T series features the highest performance handheld spectrum analyzers on the market, the company said. Providing field technicians and engineers with performance that rivals a benchtop spectrum analyzer, the MS2720T features a touchscreen and best-in-class performance for dynamic range, DANL, phase noise, and sweep speed, providing unprecedented levels of spectrum monitoring, hidden signal detection, RF/microwave measurements, and testing of microwave backhauls and cellular signals.
Continuous frequency coverage from 9 kHz to 20 GHz is provided by the MS2720T with the option 1 internal atomic clock. An improved sweep mode allows users to set resolution bandwidth from 30 kHz to 10 MHz with minimal effect on sweep speed. Because the sweep speed with a 30 kHz bandwidth is nearly the same as a 10 MHz RBW, sensitivity can be selected without the need for long sweep times.
The MS2720T has dynamic range of > 106 dB in 1 Hz RBW, DANL of -163 dBm in 1 Hz RBW, and phase noise of -112 dBm @ 10 kHz offset at 1 GHz. These best-in-class specifications are complemented by unprecedented measurement capabilities. A burst detect sweep mode function allows emitters as short as 200 microseconds to be captured every time, allowing the MS2720T to detect bursty signals that can lead to finding intermittent or bursty emitters. The burst detect sweep mode increases sweep speed more than 1,000 times in a 15-MHz span.
The internal atomic clock has a U.S. price of $5,900 and is available in 6 to 8 weeks.
Personnel with the U.S. Naval Observatory-Detachment Colorado and 2nd Space Operations Squadron move the rubidium fountain clock into its new home Tuesday at Schriever Air Force Base. The USNO monitors the GPS constellation and provides time offsets to the 2nd Space Operations Squadron for their daily navigation uploads to each individual GPS satellite. (U.S. Air Force photo/Christopher DeWitt).
The U.S. Naval Observatory’s Alternate Master Clock on Schriever Air Force Base received its second rubidium fountain clock February 4 to ensure it has the most precise time in the world.
Both the USNO’s Washington D.C.-based primary and its local Alternate Master Clock facility serve as the Department of Defense’s common time reference. Additionally, the USNO monitors the GPS constellation and provides time offsets to the 2nd Space Operations Squadron for its daily navigation uploads to each individual GPS satellite.
“With the new rubidium fountain clock, we are going from the time standard of 1 to 2 nanoseconds down to 300 picoseconds,” said Bill Bollwerk, Head of USNO Detachment Colorado.
One nanosecond is equivalent to one billionth of a second, while a picosecond is equal to one trillionth of a second. Though these small slices of time may not sound important, every nth of a second is significant, especially in GPS operations.
“A nanosecond matters because it is equivalent to a 1-foot of error for GPS,” Bollwerk said. “If the GPS satellite clocks were off by 3 nanoseconds, you have 1-meter of error introduced into GPS.”
Designed and produced by physicists at the USNO laboratory in Washington D.C., the powered rubidium fountain clock traveled by dedicated truck to Schriever. Once the fountain clock arrived at Colorado base, with the help of members of the 2nd Space Operations Squadron, the 50th Security Forces Squadron and 50th Civil Engineering Squadron, the USNO team moved it to a climate controlled chamber in the USNO’s laboratory via an airsled hover lifter.
“The 2 SOPS men and women are able to operate and provide accurate instantaneous reliable support to U.S. military forces around the world, thanks to our partnership with the U.S. Naval Observatory,” said Lt. Col. Thomas Ste. Marie, 2 SOPS commander. “We are happy to be able to work together to support their upgrade. Our relationship allows 2 SOPS to continually reach our goal of record breaking time-transfer performance and navigation accuracies.”
Although 2 SOPS was happy to support the move, it’s not as easy as one might think.
“The process of moving the rubidium fountain was very complicated,” said Ken Dreiling, USNO Detachment Colorado. “We had to ensure the fountain clock was not actually in contact with the floor or the walls as we moved it from the loading dock through the hallways and elevator into our facility.”
The careful transport of the fountain was essential to prevent damage that could affect the clock’s performance.
“The fountain clock collects billions of rubidium atoms, encased in a spherical vacuum chamber and laser-cooled to a millionth of a degree above absolute zero degrees Kelvin, approaching the coldest temperature anything can be,” Bollwerk said. “The reason we do that is because we want to observe and measure the atoms for long time in an environment that minimizes unwanted noise like the Doppler Shift.”
Though the Alternate Master Clock provides precise timing for several communication and space systems, Missile Defense Agency, DOD facilities and several civilian infrastructures around the world, the new system was installed primarily to support GPS operations.
“It is great to have the most precise time standard in the world but it is useless unless you can get it to the user, not everyone can come to the facility and set their watch,” said Bollwerk. “GPS is USNO’s primary means of providing global precise time to the warfighter. It is a great partnership between the Navy and the Air Force.”
Dreiling said the new fountain clock will help improve GPS operations.
“The new rubidium fountain clock is the next-generation new frequency standard,” Dreiling said. “This will boost the GPS’s timing by 10-fold.”
Jackson Labs Technologies, Inc., a designer and manufacturer of GPS, timing and frequency equipment, is offering the DROR-II, a 10-MHz/5-MHz/1-PPS GPS-Disciplined Atomic Frequency and Timing Reference (GPSDO).
The DROR-II is a ruggedized frequency and timing reference with a Cesium Vapor Atomic Oscillator followed by a precision SC-cut Crystal Double-Oven Oscillator and an actively vibration-compensated VCXO oscillator, with specific emphasis on ultra low phase noise performance under extreme vibration and acceleration such as could be encountered in aircraft, tracked vehicles, and wheeled vehicles.
The DROR-II unit is optimized for operation in high-vibration and high-acceleration environments that require ultra-low phase noise performance and high frequency stability under extreme conditions. The DROR-II combines the strengths of three different on-board oscillators to provide an overall performance that has not been achievable with legacy products, at a steady-state power consumption of less than 3.85W, the company said.
The DROR-II uses a GPS receiver to provide long-term phase and frequency accuracy of the built-in CSAC atomic oscillator which is followed by an SC-cut, Double Oven OCXO (DOCXO) for very high short-term stability and low phase noise, which is itself followed by a three-axis electronically vibration-compensated crystal oscillator for ultra-low-noise under high vibration. Using these four signal sources cascaded to each other allows unmatched Phase Noise and Short Term Stability (ADEV) while also providing long-term atomic holdover, very fast warmup, and long-term phase-lock to UTC. Short term stability of 1E-012 (1ppt), and phase noise floors of -162dBc/Hz are achieved. Frequency stability over 24 hours is better than 5E-013 (0.5ppt) typically when locked to GPS.
The DROR-II supplies three isolated 10-MHz Sine Wave outputs, two CMOS 1PPS, and one 5-MHz output that is phase-synchronized to UTC via the internal GPS receiver. DROR-II contains a 50-channel WAAS/EGNOS/MSAS-enabled GPS receiver that provides support for avionics systems through integrated three-axis gyro-accelerometers and a -160-dBm GPS tracking capability. DROR-II power requirements are less than 3.85W steady-state, and only a single supply of between 11.0V to 32V is required. Support for an external LCD display is standard.
The unit can be monitored and controlled by an RS-232 port or a USB port via industry standard SCPI-99 Commands (GPIB commands), and is capable of generating numerous NMEA-0183 output sentences for easy integration into existing infrastructure. The DROR-II can be ordered with various OCXO options and with different temperature ranges.
COSPAS-SARSAT beacons are battery operated emergency distress transmitters for locating ships or persons when time is critical for survival. The new Connor-Winfield series CSBxx Series are Surface Mount, 5x7mm, 3.3V, LVCMOS or Clipped Sinewave Temperature Compensated Crystal Oscillators (TCXO) designed to be emergency beacon frequency references requiring tight ± 0.2 ppm frequency stability and frequency slope control of only ±0.7 ppb/min.
The low power dissipation of 6mW allows it to power-up immediately with an accurate frequency. Class 1 devices operate over –40°C to 55°C and Class 2 devices operate–20°C to 55°C. Standard frequencies are 10.0, 12.688375, 12.688575, 12.688656, 12.68875, 16.367, and 20.0 MHz. To save time during the beacon certification process, temperature test data is available from a special on-line URL for each serialized TCXO.
Features:
3.3 Vdc Operation
Frequency Stability: ± 0.20 ppm
Mean Slope = ±0.7 ppb/min
Temperature Ranges Available:
Class I -40 to 55°C , Class II -20 to 55°C
LVCMOS or Clipped Sinewave Output
Ceramic Surface Mount Package
Tape and Reel Packaging
RoHS Compliant / Pb Free
Each unit is serialized and data is available on-line
Swiss-based u‑blox has unveiled the LEA-M8F precision timing GNSS module. The compact, surface-mount module generates a precise 30.72 MHz reference clock crucial for synchronizing industrial data and communication systems such as small, femto and macro-cell mobile networks. High accuracy is achieved by disciplining a local oscillator or other clock source with timing signals received from satellite-hosted atomic clocks.
To ensure satellite availability, LEA-M8F is able to acquire and track all 50+ GPS, GLONASS and BeiDou satellites. High sensitivity enables quick autonomous start-up even inside structures with limited sky-view.
“A reliable, compact and cost-effective precision reference clock is a crucial component used in many systems in the Critical Infrastructure and Key Resource sectors (CIKR),” said Thomas Nigg, vice president of product marketing at u-blox. “Our LEA-M8F GPS/GNSS satellite-disciplined timing module enables the proper operation of many mission-critical infrastructure systems including mobile and fixed-line communication networks, power generation and distribution systems, gas and chemical processing plants, banking, postal and goods distribution processes.”
Measuring 17 x 22 mm, the LEA-M8F module includes a low-noise 30.72 MHz VCTCXO (voltage and temperature controlled oscillator), meeting the master reference requirements for LTE Small Cells while providing 100 parts-per-billion autonomous hold-over accuracy. The module is also suitable for TD-LTE, LTE-Advanced and other applications requiring extended hold-over times when integrated with small cell platforms.
External sources of synchronization are supported through time-pulse and frequency inputs and a message interface. This allows measurements from macro-sniff, Sync-E or packet timing to be combined with measurements from GNSS to extend the availability of accurate synchronization and in doing so maximize cellular service availability.
LEA-M8F can track signals from satellites from any two constellations simultaneously (e.g. GPS and GLONASS, GPS and BeiDou, GLONASS and BeiDou). Compatibility with multiple GNSS systems gives the LEA-M8F access to a large number of satellites, allowing synchronization even in urban or indoor areas with limited sky view. For stationary applications, once a location is known, accurate timing can be maintained based on the signal from just a single satellite.
For more information, download the u-blox whitepaper “GNSS Timing and the Rise of Small Cells”. Detailed information about the LEA-M8F and evaluation kit EVK-M8F can be found on the u-blox website. Samples of the LEA-M8F will be available in Q1 2014.
Also, the LEA-M8F will be demonstrated at the Small Cells Americas exhibition in Dallas, Dec. 3-4, at u-blox stand number 3.
The FTS500 Xenith TBR (Time Base Reference) by Connor-Winfield is designed for DVB/DAB, wireless communications, time-stamping, or any other timing vital application.
The Xenith TBR module is a GPS-driven, mixed-signal phase lock loop, providing a 1PPS CMOS output and generating a 10-MHz SINE output from an intrinsically low jitter voltage controlled crystal oscillator (VCXO). The 10-MHz output is disciplined from an on-board GPS receiver, which drives the long-term frequency stability. Its on-board CW25 timing GPS receiver along with a dual-oven system provides the highest quality timing and synchronization signals combined with superb hold-over characteristics. The unit is housed in a 106 x 125 x 56 millimeter strong aluminum enclosure.
The CW46S GPS sensor by NavSync is a fully integrated module that includes a CW25 GPS receiver, DC/DC converter, RS232 or RS422 interface options, and active GPS antenna housed in a small weatherproof (IP67-rated) enclosure.
When mounted with a good sky view, the CW46S receiver can provide high-quality timing and synchronization. The 1 pulse per second (PPS) timing signal can provide accuracies to within 30nS RMS of Coordinated Universal Time (UTC).
The 1PPS is transmitted via RS422 signal format; this two-wire method allows the pulse to be transmitted with cable lengths exceeding 100 meters.
The CW46S utilizes the CW25TIM GPS receiver, which allows the CW46S to act as a complete timing module capable of outputting a GPS-disciplined 10-MHz frequency.
Microsemi Corporation has entered into a definitive agreement with Symmetricom to acquire the precision time and frequency company for $230 million. Microsemi is a provider of semiconductor solutions differentiated by power, security, reliability and performance.
Microsemi, headquartered in Aliso Viejo, California, will pay $7.18 per share through a cash tender offer, representing a premium of 49 percent based on the average closing price of Symmetricom’s shares of common stock during the 90 trading days ended October 18. The board of directors of Symmetricom unanimously recommends that Symmetricom’s stockholders tender their shares in the tender offer. The total transaction value is approximately $230 million, net of Symmetricom’s projected cash balance at closing.
Headquartered in San Jose, California, Symmetricom provides highly precise timekeeping technologies and solutions that enable next-generation data, voice, mobile and video networks and services. It provides timekeeping in GPS satellites, national time references, and national power grids as well as in critical military and civilian networks.
“The acquisition of Symmetricom will create the largest and most complete timing portfolio in the industry today,” stated James J. Peterson, Microsemi president and chief executive officer. “From source to synchronization to distribution, Microsemi will offer an end to end timing solution for an expanded range of markets, driving increased dollar content opportunity and revenue growth.”
“The acquisition of Symmetricom by Microsemi will create a powerful combination,” said Elizabeth Fetter, Symmetricom’s chief executive officer. “I believe Microsemi is the ideal company to leverage Symmetricom’s technology and capabilities further into the communications market along with the scale to accelerate the adoption of the company’s innovative new chip scale atomic clock (CSAC) technology into broader markets.”
Microsemi expects significant synergies from this immediately accretive transaction. Based on current assumptions, Microsemi expects the acquisition to be $0.22 to $0.25 accretive in its first full calendar year ending December 2014.
Microsemi reaffirms its fiscal fourth quarter guidance included in its fiscal third quarter earnings release issued on July 25. Microsemi currently intends to announce its fiscal fourth quarter results on November 7. Further details will be forthcoming.
Tender Offer and Closing. Under the terms of the definitive acquisition agreement, Microsemi will commence a cash tender offer to acquire Symmetricom’s outstanding shares of common stock at $7.18 per share, net to each holder in cash. Upon satisfaction of the conditions to the tender offer and after such time as all shares tendered in the tender offer are accepted for payment, the agreement provides for the parties to effect, as promptly as practicable, a merger which would result in all shares not tendered in the tender offer being converted into the right to receive $7.18 per share in cash. The tender offer is subject to customary conditions, including the tender of at least a majority of the fully diluted shares of Symmetricom’s common stock and certain regulatory approvals, including the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act, and is expected to close in Microsemi’s fiscal first quarter, ending Dec. 29, 2013. No approval of the stockholders of Microsemi is required in connection with the proposed transaction. Terms of the agreement were unanimously approved by the boards of directors of both Microsemi and Symmetricom.
Under the terms of the merger agreement, Symmetricom may solicit superior proposals from third parties for a “go shop” period that extends through November 8. It is not anticipated that any developments will be disclosed with regard to this process unless and until Symmetricom’s board of directors makes a decision to pursue a potential superior proposal. Jefferies LLC, which is acting as Symmetricom’s financial adviser, will assist Symmetricom with Symmetricom’s go-shop process. There are no guarantees that this process will result in a superior proposal. The merger agreement provides Microsemi with a customary right to match a superior proposal. The agreement also provides for certain termination fees payable to Microsemi in connection with the termination of the agreement in certain circumstances.
Conference Call. Microsemi will host a conference call, solely to discuss details of the transaction. A live webcast relating to the transaction will be available in the “Investors” section of Microsemi’s website at www.microsemi.com in advance of the conference call.
