RT User Manual
Revision: 190902
7
Introduction
The RT family of inertial navigation system (INS) devices are instruments for making
precision measurements of motion in real time.
There are three divisions within the RT family – RT500s (v1) RT3000s (v3) and
RT1003s (v1) – and each division has performance options. The RT500 and RT3000
products are covered in this manual. The RT1003 product has its own manual, which
can be downloaded from the OxTS Support Site
From September 2019 the RT3000 became v3 with new functionality. v2 devices are
now end of life and include: RT2000s, RT3000s (v2), and RT4000s. The RT1003 is
unchanged.
The “RT-Range Hunter” is a variant of the RT3000 v3 that runs the OxTS RT-Range
processing engine for vehicle-to-vehicle and vehicle-to-lane testing inside the RT
itself. This functionality used to be available from the RT-Range S Hunter accessory
but now runs on board the RT3000 v3 as an optional feature. If you are configuring an
RT-Range S Hunter for ADAS testing then you will need to refer to the RT-Range
user manual – available to download at support.oxts.com.
To obtain high-precision measurements, the RT uses mathematical algorithms
developed for use in fighter aircraft navigation systems. An inertial sensor block with
three accelerometers and three gyros (angular rate sensors) is used to compute all the
outputs. A WGS 84 modelled strapdown navigator algorithm compensates for earth
curvature, rotation and Coriolis accelerations, while measurements from high-grade
kinematic GNSS receivers update the position and velocity navigated by the inertial
sensors. This innovative approach gives the RT several distinct advantages over
systems that only use GNSS:
•
The RT has a high (100 Hz, 200 Hz or 250 Hz) update rate and a wide bandwidth.
•
The outputs are available with low, 1 ms latency.
•
All outputs remain available continuously during GNSS blackouts when, for
example, the vehicle drives under a bridge.
•
The RT recognises jumps in GNSS position and ignores them.
•
The position and velocity measurements the GNSS makes are smoothed to reduce
the high-frequency noise.
•
The RT makes many measurements GNSS cannot, for example acceleration, angular
rate, pitch and roll.