GPS World

Tag: GPS simulator

  • Portable Time-Loader ready for field deployment

    Portable Time-Loader ready for field deployment

    Image: Focus Telecom
    Image: Focus Telecom

    Focus Telecom has introduced a new timing product for defense and mission-critical applications, the Time-Loader.

    The Time-Loader can be deployed in environments where GNSS signals are denied or disrupted, to support any ground, naval and airborne system that needs real time of day (TOD) and 1PPS external synchronization aligned to UTC or GNSS.

    In this emerging era of rapid tactical deployment of defense systems, communications intelligence, missile defense systems, radar/electro-optical sensors and UAS batteries in the field are often in GNSS-denied or jammed environments. This situation creates challenges for access to real time and accurate time of day.

    To solve this problem, the Time-Loader generates a GPS L1 C/A code RF output as if the signal were coming from a live-sky GPS antenna. It provides full-constellation GPS output and is compatible with external GNSS receivers. It encodes times with nanosecond accuracy for GPS timing receivers.

    The Time-Loader’s GPS-disciplined oscillator (GPSDO) is the Microsemi MAC-SA53/55, which provides excellent UTC accuracy with outstanding hold-over rubidium clock performance.

    The Time-Loader is the size of a suitcase, hand-carried and easily deployed. It activates quickly from a cold start or when sensors are deployed for the first time.

    Included in the Time-Loader is a self-contained, miniature GPS simulator that provides real-time extremely accurate signals. The 18-channel full-constellation simulator stores location/time/date data in internal memory and stores complex vector data to simulate dynamic scenarios. The simulator also can be used to transcode NMEA or SCPI position/velocity/time (PVT) data into GPS RF signals.

    Learn more about the Time-Loader.

  • New JLT Micro-Transcoder provides GPS firewall retrofit

    New JLT Micro-Transcoder provides GPS firewall retrofit

    Jackson Labs Technologies Inc. (JLT) released its tiny, new Micro-Transcoder, a full-constellation, stand-alone, real-time 10-channel GPS simulator. The unit can act as a GPS firewall to identify and block jamming and spoofing attempts, and to provide an alternate PNT source during fully GPS-denied operation.

    JLT is a designer and manufacturer of GNSS, timing and frequency equipment.

    Photo: JLT
    Photo: JLT

    The one-inch-square Micro-Transcoder module allows glueless retrofitting of existing GPS equipment by upgrading systems with secure and assured positioning, navigation and timing (PNT) capability, the company said. It achieves hardening of the customers’ GPS equipment by splicing the unit in between the existing antenna and the users’ GPS receiver.

    It takes the output of any secure PNT source — inertial navigation system (INS), SAASM, M-code, Iridium STL, or concurrent GNSS receiver — and encodes (RF modulates) the baseband PNT and UTC timing information into a standard GPS L1 RF signal.

    This RF signal can then be received by any legacy GPS receiver.

    The unit is based on JLT’s CLAW GPS simulator and RSR transcoder technologies, and includes a stand-alone full-constellation 10-channels real-time GPS simulator with integrated high-stability timing reference, as well as an internal GNSS receiver for monitoring the RF output signal for quality and accuracy.

    The unit will transmit a standard UTC time, position, velocity and heading GPS L1 RF signal by simply applying 3.3V power to it.

    The Micro-Transcoder can also be operated as a generic high-performance GPS simulator with built-in GPS Disciplined Oscillator, and is supported by a comprehensive free Windows application program downloadable from the JLT website.

    The Windows application allows control of all the simulation aspects, creating and storing simulation vector commands, and testing user equipment for leap-second and GPS week rollover event compatibility to identify weaknesses in user equipment.

    The unit does not require a PC to be connected to it to function. This makes embedded operation as easy as applying power, and connecting the units’ RF output to the antenna input of any GPS receiver.

    By generating a legacy RF GPS signal from any secure PNT source, the Micro-Transcoder allows users to maintain their investment in fielded legacy GPS equipment. Example applications include retrofitting financial transaction time servers with CSAC or rubidium atomic clock holdover capability, and adding GPS RF output capability to concurrent GNSS receivers to allow reception of L1, L2, L3, L5 GPS, GLONASS, Galileo, BeiDou, QZSS, Iridium STL, or any other satellite-based navigation signal to legacy GPS receivers.

    It can also be used to add inertial navigation system (INS) capability to vehicles and aircraft.

    None of these applications require any modifications to be made to the legacy GPS receiver system; all configurations are done externally using the Micro-Transcoder Windows application or a standard terminal program, and on the assured PNT source.

    A real-world customer application is a data-center where communications equipment required a GPS signal to operate. The user wanted to prevent vulnerabilities that an external antenna would have introduced. In this scenario, the Micro-Transcoder provided a fixed-position GPS RF signal to a number of the data centers’ GPS receivers, and allowed the GPS user equipment to operate properly without exposing it to the possibility of external jamming or spoofing.

    At 0.97 x 0.97 x 0.4 inches and with less than 0.95W power consumption, the Micro-Transcoder is small enough to be designed into emerging assured PNT products, allowing them to communicate gluelessly to existing legacy GPS infrastructure.

  • Jackson Labs offers CLAW simulator

    Jackson Labs offers CLAW simulator

    Jackson Labs Technologies Inc. (JLT) is offering the CLAW GPS/GNSS simulator. Designed with small size, weight and power (SWAP), the CLAW is only slightly larger than a standard deck of cards.

    CLAW targets applications that require small, low-power and low-cost GNSS synthesis with repeatable and highly accurate GNSS RF signals such as production testing of GNSS receivers, simulating GNSS anomalies such as leap-second events, 1023 GPS Week roll-overs, simulated operation in inaccessible locations around the world, real-time transcoding of different GNSS systems, and testing using dynamically user-configured RF signal levels.

    jackson_labs-claw-wWith nanosecond-accurate encoding, CLAW is particularly suited to allow easy stress-testing of GPSDO frequency and timing reference products such as JLT’s GNSDOs under various different mission scenarios, the company said.

    The CLAW GNSS simulator is a no-frills solution that contains real-time processing hardware to simulate GPS constellations without the need to connect any external equipment other than a USB power source or power supply.

    Providing a real-time computed RF output signal rather than an offline file-playback differentiates CLAW from competitive solutions that are only capable of recording and playback operation in non-real-time, or require offline computation of data files using external computers that are played back on the simulation device.

    CLAW is a completely self-contained, ruggedized, miniature, real-time hardware GPS simulator.

    Navigation coordinates and 1PPS timing pulses can be provided in real-time through the NMEA and SCPI compatible USB interface or via the built-in RS-232 interface, and are encoded in the CLAW into RF GPS signals in real-time with nanosecond-level accuracy and minimal delay.

    Position, velocity and timing (PVT) information may be provided as a simple NMEA stream from an external source such as an inertial navigation system (INS), Galileo/GLONASS/BeiDou/SAASM GNSS receiver, and CLAW will encode this PVT data into standard L1 C/A GPS RF signals in real-time with minimal phase/position shifts. This allows real-time GNSS transcoding of any other GNSS standard simply by connecting an external GNSS receiver, INS system or PVT source to the RS-232 inputs of the CLAW, allowing retrofit of existing legacy equipment with the latest GNSS systems.

    CLAW includes glueless drivers for Rockwell Collins Remote Secure Receiver (RSR Puck) among others, allowing transcoding of assured, secure L2 P(Y) code into legacy L1 C/A code in real time to retrofit commercial receivers with military P(Y) capability. CLAW also allows user-entry of ephemeris and almanac information, providing a means to simulate any past or future GPS constellation and time/date event, the company added.

    CLAW was designed with a particular emphasis to encoding the optional externally-provided 1PPS GPS system time with nanosecond-level accuracy targets, allowing accuracy testing of GPS timing and frequency devices on top of simply providing a positioning/velocity reference. CLAW initially will support GPS L1 C/A code encoding with up to 12 satellites, and later versions will support additional GNSS systems such as L2 GPS, GLONASS, BeiDou and Galileo.

    A comprehensive cost-free optional user application for Windows will be offered that allows control and monitoring of the unit, creation of simulation scenarios using Google Earth and manual waypoint entry, among other options. The unit also can be controlled via simple serial terminal commands, or various other available public-domain freeware programs.

    Once position information is stored in the units’ NVRAM, the unit will generate GPS RF constellations within seconds upon power-up and thus does not require any user interaction other than plugging in the power supply.

    CLAW contains a highly accurate and stable internal 10-MHz reference oscillator that may optionally be synchronized by an external 1PPS reference, 10-MHz reference, or both. CLAW supports a user-selectable RF signal attenuation range of 63 dB in 0.5-dB steps, allowing a wide range of RF signal levels to be generated with high accuracy and power-level resolution. Antenna DC power consumption also can be controlled via software command.

    CLAW can be powered by its USB interface, or by a 6.5V to 28V DC power feed, and consumes less than 1.7W allowing extended operation of 24 hours or more from low-cost ubiquitous USB consumer battery packs.

  • ION GNSS+ 2015: Spectracom presents GPS, GNSS simulator product line

    Rohit Braggs, vice president of sales and marketing for Spectracom, talks about the company’s GPS and GNSS simulator product line at ION GNSS+ 2015 in Tampa, Fla.