GNSS SOLUTIONS

摘要

Q:What is your most proven GNSS solution? A: CAST Navigations most popular and proven solution is the CAST-Inertial System, which is an inertial-output-capable EGI tester. This simulator has been in production since the early 1990s. With it, we have successfully been able to simulate both the Honeywell and Northrop Grumman embedded GPS inertial (EGI) navigation units. Since then, we have added the capability to drive Kearfott, Emcore (formerly known as Systron Donner) and the ability to add other IMU definitions and outputs if needed. By executing a test scenario on the EGI tester, we can drive an EGI so that it "thinks" it is moving through 3D space, even though it is sitting stationary in a laboratory. Because an EGI unit consists of both a GPS receiver and an inertial measurement unit (IMU), this is not an easy task. The navigation unit will override any GPS signals that do not agree with the measurements the IMU is sending. Providing a dynamic GPS signal is not sufficient. CAST drives the EGI's computer with both GPS and inertial signals that are coincident, that is, virtually identical in overall stimulus. The EGI is put into test mode, which allows the CAST-Inertial System to input dynamic, simulated inertial data based on the track of the host vehicle that is being simulated.