Odometer Automatic Pulse Length Calibration Procedure; Reversing Detection; Motion Analysis; Raim - Advanced Navigation Spatial FOG Dual Reference Manual

10.9.1

Odometer Automatic Pulse Length Calibration Procedure

1. Ensure that the signal is connected correctly and that the GPIO pin is configured
as an odometer input using the GPIO configuration dialogue in Spatial FOG
Manager, see section 11.8.6.
2. Open Spatial FOG Manager, connect to Spatial FOG Dual and open the odometer
configuration dialogue. In the odometer configuration dialogue tick the
automatic pulse length calibration check box and press the write button, see
section 11.8.7.
3. Wait until Spatial FOG Dual has a continuous GNSS fix and then drive 1000
metres over flat terrain with as little turning as possible.
4. If Spatial FOG Dual loses a GNSS fix for any extended period of time during the
calibration, the distance travelled will be reset. The distance travelled can be
checked in the odometer configuration dialogue to ensure that it has passed
1000 metres.
5. Once 1000 metres has been driven, press the read button and check that the
automatic pulse length check box becomes un-ticked and the pulse length value
is read.
10.10

Reversing Detection

Reversing detection is an algorithm that can detect when the vehicle is travelling in
reverse. Knowledge of reverse motion is important when using velocity heading or
odometer input to provide correct results. If Spatial FOG Dual is fitted to a vehicle that
does not reverse or doesn't use velocity heading or odometer, this function should be
disabled. Reversing detection is enabled by default and it can be disabled using the
filter configuration dialogue in Spatial FOG Manager, see section 11.8.2.
10.11

Motion Analysis

Motion analysis is an artificial intelligence algorithm that associates patterns in high
frequency inertial data with the speed of the vehicle. After power on it takes some
time to match patterns with speed before it will become active. Motion analysis only
activates when dead reckoning and is most effective when the vehicle is near
stationary. Motion analysis does not work in all situations and it's primary benefit is in
ground vehicles. When active it can be recognised by 2Hz steps in velocity data.
Motion analysis is disabled by default and can be enabled using the filter configuration
window in Spatial FOG Manager, see section 11.8.2.
10.12

RAIM

RAIM stands for receiver autonomous integrity monitoring. It allows a GNSS receiver to
detect and exclude both faulty and fraudulent satellite signals. Spatial FOG Dual's
internal GNSS is equipped with RAIM and it is enabled by default.
10.13

RTK

Spatial FOG Dual's internal GNSS receiver supports RTK GNSS which uses correction
Spatial FOG Dual Reference Manual
Page 44 of 138
Version 1.0
26/06/2015