GPS (Global Positioning System) has evolved into critical devices deployed for a variety of industrial, commercial, and security applications, from international defense to environmental mapping down to tracking cargoes and parcels. The GPS is constantly augmented with other technologies, according to CAST Navigation, to make it as powerful and fail-proof as possible. Testing for the performance of GPS entails the use of a GPS signal simulator.
GPS Signal Simulator
GPS Signal Simulator (also called GPS signal generator) is an instrument that generates radio frequency that can transmit the exact data to a ground receiver in the form of GPS satellites. The satellites transmit identification information and navigation message containing the synchronized time, ephemeris (orbital data) and almanac (expected positions of all the satellites). From these data, you can calculate the position and distance of the object.
How GPS Signal Simulator Works
Signal acquisition, retention, and performance in different environments are key elements in ensuring the success of a GPS device. GPS Signal Simulator can convert a variety of data parameters during testing, enabling GPS developers to come up with a device with optimized capabilities of current and advanced GNSS systems and guarantee performance. The combination of these data makes up the simulation scenario:
1. Satellite data (date and time, satellite ID or PRN code and the Ephemeris and almanac data)
2. Receiver Condition data (number of satellite signals, atmospheric and antenna-induced errors, power level and multi-path conditions)
3. Receiver Position data (latitude, longitude, elevation and motion path or object trajectory)
Benefits of Using GPS Signal Simulator
Aside from GPS Signal Simulator, there are also other ways to test a GPS device: Live Sky (over-the-air signal testing that cannot be repeated) and Recording and Playback.
By far, the signal simulator offers the best option for test engineers as it gives them flexibility as well as full control over the signal generation, translating to guaranteed top performance of the GPS hardware and software under any condition. It also validates more firmly the plan of assembly, thanks to the availability of the data parameters from which the device is being tested. For businesses, it saves on development time and cost due to the repeatability of simulation and reliability.
What to Look for in GPS Signal Simulators
- Multi-channel that can simultaneously generate signals from many satellites
- Can test multi-GNSS capability and other global navigation satellite systems.
- Can generate signals from multi-point SBAS (satellite-based augmentation systems).
The GPS signal simulator is crucial in testing a GPS device to ensure flexibility in reading and transmitting data. It guarantees the top performance of the GPS, especially in mission-critical applications. It also has enabled many companies, even without huge research and development budgets, to participate in the development of navigation devices.