What Is a GPS Signal Generator?

What Is a GPS Signal Generator?
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A cost effective GPS signal generator is a device primarily used by manufacturers of GPS receivers to test their GPS capabilities. These generators emulate GPS satellite signals that can be used by GPS receivers to determine their location. Using these in tests can determine whether a GPS receiver is built correctly with all its required parts functioning properly such as the antenna. GPS receivers that are tested with this device include mobile phones with GPS capability. It is a fast and efficient way of doing controlled tests on these GPS-enabled devices so companies find these low cost signal generators very useful.

Examples of GPS Signal Generators

The most popular GPS signal generator is the GSG-L1 by Pendulum Instruments. It provides accurate GPS generated signals via a single channel with a wide RF output power range that allows for air-to-air, as well as conducted testing. This is what GPS receiver manufacturers use in their production testing. Its input and output protocol is easily programmable, allowing manufacturers to customize their testing procedures or perform different tests with different settings.

The GSG-54 is the next step in the evolution of the GSG-L1. Instead of using a single channel for signal emulation, it uses eight channels. It also includes preset test scenarios that makes testing GPS receivers more efficient. It is designed to be compact and portable with all the intuitive controls accessible through the front panel. It does not just make the whole testing procedure faster and more effective, it also adds new features like navigational fixes and position testing that are not found in the GSG-L1 device.

These generators give manufacturers the ability to test their GPS receivers in multiple controlled scenarios in a quick and efficient manner that ensures their products’ quality without putting too much effort in it. These devices are very handy and don’t require a lot of training for their operation. Allowing users to upload their own GPS data in a standard format makes these devices flexible and versatile, adding strong value to their low cost price.

The Threat of GPS Signal Generators

A GPS signal generator is not just used in the production testing of GPS receivers. It can also be used to spoof GPS signals, which basically means it tricks users of GPS receivers that what they are seeing on their devices is their actual location. In industrial situations, there is no harm in generating and receiving fabricated GPS data from the generators. It is an essential part in testing GPS receivers. However, outside industrial settings, emulation of GPS data can be used for malicious attacks or activities.

It is quite difficult to say if the signal being received by a GPS data receiver is real or not because the signals used in civilian GPS receivers are in a common format and is usually unencrypted. It is almost impossible to detect which signals are true and which ones are fabricated by a signal generator. Since the signal generators are low cost, they can easily be acquired by people with enough resources to be used any way they want.


Usinenouvelle, https://www.usinenouvelle.com/industry/pendulum-instruments-8630/gsg-l-gps-signal-generator-p99799.html

Aspen Electronics, https://www.aspen-electronics.com/page.asp?page=pendulum

GPS World, https://www.gpsworld.com/gnss-system/expert-advice-location-assurance-4165

Photo Courtesy of Wikimedia Commons / Supplied by DevCom