RT4020

	Higher Accuracy Unit: RT4002 Lower Cost Unit: RT4100

The RT4020 Inertial and GPS Navigation System is an advanced six-axis inertial navigation system that incorporates an L1 RTK GPS receiver and delivers better than 0.2m CEP positioning under dynamic conditions using differential corrections. The RT4020 delivers 1.8m CEP using the standard positioning service.

The RT4020 Inertial and GPS Navigation System includes three angular rate sensors (gyros), three servo-grade accelerometers, the GPS receiver and all the required processing in one very compact box. The RT4020 works as a standalone, autonomous unit and requires no user input before it starts operating.

The outputs from the RT4020 Inertial and GPS Navigation System are derived from the measurements of the accelerometers and gyros. Using the inertial sensors for the main outputs gives the RT4020 system a fast update rate (250Hz) and a wide bandwidth. All the outputs are computed in real-time with a very low latency.

The RT4020 Inertial and GPS Navigation System outputs its real-time measurements over CANbus, RS232 and Ethernet. Optional outputs can be made using Analogue.

The internal processing includes the strapdown algorithms (using a WGS-84 earth model), Kalman filtering and in-flight alignment algorithms. The internal Pentium-class processor runs QNX real-time operating system to ensure that the outputs are always delivered on time. The Kalman filter monitors the performance of the system and updates the measurements using GPS. By using the measurements from GPS, the RT4020 system is able to maintain highly accurate measurements and correct its inertial sensor errors.

To obtain measurements accurate to 0.2m, the RT4020 requires differential corrections from a suitable base-station. The RT-Base-20 can provide suitable corrections for the RT4020.

All the members of the RT4000 share a common platform; lots of documentation is available about the RT4000 Family and applies to the RT4020. Use the following links to obtain more information on the RT4000 products.

	Overview Get and overview of the RT4000 family.			Operation Operation of the RT4000 is very easy. Learn why.
	Technologies Learn more about the technologies used in the RT4000.			Output Formats Learn more about the output formats of the RT4000.
	Measurements Learn more about the measurements made by the RT4000.			Connectivity Learn more about how to connect your RT4000 to your current system.