SPAN Operation

Chapter 3

3.2.5.3Set up a Wheel Sensor

1. Send the following commands to setup the wheel sensor.

ENCLOSUREWHEELSENSOR ENABLE 1HZ

SETWHEELPARAMETERS ticks circ spacing

The parameters entered in the SETWHEELPARAMETERS command depend on the wheel sensor being used. See the OEM6 Family Firmware Reference Manual (OM-20000129) for more information about this command.

2.Send the following commands to log the wheel sensor data.

LOG TIMEDWHEELDATAB ONNEW

LOG WHEELSIZEB ONCHANGED

3.3Azimuth Sources on a SPAN System

The SPAN system use three different methods to calculate the azimuth.

•Course Over Ground

•Inertial Azimuth

•ALIGN Azimuth

3.3.1Course Over Ground

The course over ground azimuth is determined using the position delta between two position solutions computed by the SPAN-IGM. This is the simplest way to compute an azimuth and is done using either the GNSS solution or the INS solution. This method does not work when the vehicle is stationary as any position difference is due to position error and the computed azimuth is meaningless.

Course over ground azimuth is of greatest advantage in aerial or marine environments where the actual direction of travel may not match the forward axis of the aircraft/boat due to winds or currents. This effect is known as the crab angle. Course over ground azimuth is a great way to compute the offset if another means of computing the vehicle azimuth are available.

Course over ground azimuths are available in several different velocity logs. See Table 6, Logs with Azimuth data on page 36.

3.3.2Inertial Azimuth

The inertial azimuth computed by the SPAN inertial navigation filter. It uses the sensors in the IMU to compute the azimuth of the IMU (this can be rotated to another reference if desired). For more information, see the APPLYVEHICLEBODYROATION and VEHICLEBODYROTATION commands in the SPAN on OEM6 Firmware Reference Manual (OM-20000144).

This azimuth is the one provided in the majority of the INS logs available to a SPAN user. See Table 6, Logs with Azimuth data on page 36.

3.3.3ALIGN Azimuth

On SPAN systems with dual antennas, an azimuth is available from the dual antenna baseline. This is the same azimuth that is used as an update to the SPAN solution. It is noisier than the inertial azimuth and is available at a much lower rate, but will have a stable mean. This azimuth is computed from the master antenna to the rover antenna based on how the antennas are oriented on the vehicle.

There is a specific subset of logs that output this azimuth. See Table 6, Logs with Azimuth data on page 36.

SPAN-IGM User Manual Rev 2

35

Page 34 Page 36
Page 35
Image 35
Novatel OM-20000141 user manual Azimuth Sources on a Span System, Course Over Ground, Inertial Azimuth, Align Azimuth
Page 34 Page 36

OM-20000141 specifications

The Novatel OM-20000141 is a high-performance multi-GNSS (Global Navigation Satellite System) receiver designed for various applications including precision agriculture, autonomous vehicles, and surveying. This state-of-the-art device combines cutting-edge technologies to provide accurate and reliable positioning data, making it an indispensable tool for professionals in fields that rely on geolocation.

One of the standout features of the Novatel OM-20000141 is its multi-frequency support, allowing it to receive signals from GPS, GLONASS, Galileo, and BeiDou systems. This capability significantly enhances the accuracy and reliability of positioning information, particularly in challenging environments where signal interference can occur. By utilizing multiple frequencies, the OM-20000141 can mitigate errors caused by atmospheric disturbances and multi-path signals, resulting in improved precision.

In addition to its multi-GNSS capabilities, the receiver incorporates advanced RTK (Real-Time Kinematic) technology, enabling centimeter-level accuracy. This is particularly beneficial for applications that require pinpoint geolocation, such as precision agriculture, where farmers need to optimize crop yields and resource usage. The RTK technology allows users to achieve real-time positioning corrections, making it a vital tool for surveying and construction projects that demand high precision.

The Novatel OM-20000141 also features built-in connectivity options, including Bluetooth and USB interfaces, facilitating seamless integration with other devices and systems. This connectivity is crucial for enabling real-time data sharing and remote monitoring, enhancing the usability of the device in various operational environments.

Robustness is another significant characteristic of the OM-20000141. Designed to withstand harsh conditions, the receiver features a durable housing that protects it from dust, moisture, and extreme temperatures. This resilience ensures that the device operates effectively in all weather conditions, making it suitable for outdoor applications.

Furthermore, the receiver is equipped with intelligent positioning algorithms that optimize performance in urban canyons and dense foliage areas, where traditional GNSS receivers may struggle. By leveraging these algorithms, the OM-20000141 can maintain reliable positioning even in challenging environments.

Overall, the Novatel OM-20000141 stands out as a versatile and reliable GNSS receiver, merging advanced technologies to deliver high accuracy and reliability. Its exceptional features make it an invaluable asset for professionals in various industries, enhancing their ability to achieve precise geolocation and optimize their operations.
Top Page Image Contents