CLAW GPS Simulator

GPS Simulator and GNSS-to-GPS Transcoder

Unique simulator for standalone applications in manufacturing and R&D.

CLAW GPS Simulator CLAW GPS Simulator

The CLAW GPS Simulator is a small, low-cost, 18-channel full constellation, GPS/GNSS simulator for converting NMEA and SCPI PVT (position/velocity/time) data into GPS RF signals and for simulating GNSS jamming and GPS spoofing scenarios.

The CLAW can also be used to retrofit legacy GPS clocks with the latest generation of GNSS receivers, such as Galileo, GLONASS, BeiDou, SAASM, M-code, or even with INS capability.

The CLAW is ideal for the following applications:

  • Manufacturing environments and R&D applications that require consistent and repeatable local GNSS signals at low price points.
  • Simulating GNSS jamming scenarios as well as GPS spoofing scenarios.


  • 18-Channel GPS Simulation
  • Real Time Transcoding
  • Fully Self-Contained
  • Powered by USB or external source
  • Highly Accurate simulation
  • Wide-range RF output power control
  • Store extensive dynamic simulation scenarios

Frequently Asked Questions

  • Does the CLAW have a simulation time limit, or can it run forever?
    • Yes, the CLAW can run forever and there are simulation time limits.
  • Do I have to specify the Time and Date of the simulation? Can it simulate future time and dates?
    • The Simulation can use real-time and date, or it can be started with any user-defined time and date (past and future dates).
  • How does the CLAW determine the constellation that is simulated? Can I upload live-sky conditions, and my own Almanac?
    • Live Sky or customer-supplied Almanacs (available from a NASA website) can be uploaded and stored in the CLAW NV Memory to align the simulation with the real-world GPS constellation at any specified time.
  • How is the CLAW typically used?
    • The CLAW can be operated in the following ways:
    • Manual control of ToD, Position and Navigation, and/or jamming signals via the SimCon application.
    • Real-Time “hardware in the loop” Transcoding of NMEA data streams from external NMEA RS-232 sources.
    • Uploading of NMEA files.
    • Creating and storing complex vector files in the CLAW NV memory using the Graphical SimCon tool
    • Automatically executing stored vector files or stationary position simulations as soon as power is applied, so only an external USB power source is needed.
    • Sending scripted control command to the unit using the USB or RS-232 serial ports.
  • Can I broadcast the CLAW output signal in my anechoic chamber to use it to test my GPS devices with built-in antenna from a distance of perhaps ten feet?
    • The CLAW output signal can be amplified with low-cost external L1 amplifiers to be able to transmit the RF signal inside, e.g. an anechoic chamber using a passive GPS antenna (available from VIAVI).
  • How can I monitor the CLAW RF output? Why is there a GNSS receiver built-into the CLAW?
    • The CLAW GPS Simulator has a built-in uBlox GNSS receiver that is connected to the L1 RF output of the CLAW. This allows real-time tracking of the GPS Simulation performance without having to connect an external GPS receiver to the CLAW output.
  • How do I use the CLAW GPS Simulator to help me verify how well my GPS device is working?
    • The CLAW GPS Simulator has a built-in RS-232 port, and any industry-standard external GNSS receiver with standard NMEA output (and some custom receivers) can be connected to the CLAW. The CLAW can then display the horizontal, vertical, and 1 PPS timing offsets and errors that the customer's GNSS receiver has versus “simulator truth”. This allows an easy feedback loop to check any kind of GPS equipment on-the-line in real-time in aircraft, vehicles, or handheld GPS devices. All that is needed from the customer's GPS receiver is an RS-232 serial port output with standard NMEA sentences on it.

  • Fully self-contained, stores location/time/date data in internal NV memory, or by storing complex vector data to simulate highly dynamic scenarios.
  • Accurate control of RF output power ranging from  100 dBm to less than –130 dBm, with 0.1 dB resolution, and typically better than 1.5 dB accuracy over the controllable power range.
  • Random scenario generation, including the simulation of Leapsecond events, week 1023 rollover events, or any other GPS Live-Sky scenarios.
  • Multipath simulation, using the entire 18 channel simulator capability.
  • Easy in-field software upgrade feature.
  • Built-in RF signal generator with sweep, CW and random noise functions that are useful in simulating GNSS jamming scenarios, as well as GPS spoofing scenarios.
  • FCC-certified, has 10 MHz and 1 PPS I/O, accepts an external 10 MHz reference, and is kitted with various accessories. 
  • Easy-to-use, configurable freeware SimCon Windows application.
  • Standalone simulator does not require an external computer for processing or control.

SimCon Application

The SimCon Windows application is an easy to use, yet highly configurable application for use for operating the CLAW simulator.

Download Now