Jackson Labs Technologies Inc. (JLT) has entered the GNSS simulation and synthesis market with the small size, weight and power (SWAP) CLAW GPS/GNSS simulator. 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.
With 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.
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.
CLAW pre-production GPS simulator evaluation units are shipping to select customers, and are priced at $2,995 each.
