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Novatel OM-20000141 user manual Span Wheel Sensor Messages, Measurement Timing and Frequency

Models: OM-20000141

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Chapter 3

SPAN Operation

7.When the uncertainties of the offsets are low enough to be used for a kinematic alignment, the calibration stops and the VEHICLEBODYROTATION log is overwritten with the solved values. To monitor the progress of the calibration, log VEHICLEBODYROTATION using the ONCHANGED trigger.

To save a calibrated rotation for subsequent start ups, issue the SAVECONFIG command after calibration is complete. Each time the SPAN-IGM is re-mounted this calibration should be performed again. See also Kinematic Alignment on page 31 for details on kinematic alignment.

rotation parameters present and a kinematic alignment is NOT possible. Therefore this command should only be entered after the system has performed either an alignment and has a valid INS solution.After the RVBCALIBRATE ENABLE command is entered, there are no vehicle-body

The solved rotation values are used only for a rough estimate of the angular offsets between the SPAN-IGM and vehicle frames. The offsets are used when aligning the system while in motion (see System Start-Up and Alignment Techniques on page 30). The angular offset values are not applied to the attitude output, unless the

APPLYVEHICLEBODYROTATION command is enabled.

3.2.5SPAN Wheel Sensor Messages

The SPAN-IGM supports wheel sensor inputs. The SPAN-IGM accepts TTL level input pulses from a wheel sensor through the AUX connector. See Appendix A, Technical Specifications on page 52 for specifications on the wheel sensor interface.

3.2.5.1Measurement Timing and Frequency

Typical wheel sensor hardware generates wheel ticks constantly as the wheel rotates. The SPAN-IGM interface is configured to accumulate wheel sensor tick counts at a rate of 1 Hz.

3.2.5.2Wheel Sensor Update Logic

Wheel sensor data is available through the TIMEDWHEELDATA log. The TIMEDWHEELDATA log can be used for applying wheel sensor updates in post-processing.

The SPAN filter uses sequential TIMEDWHEELDATA logs to compute a distance traveled between update intervals (1 Hz). This information is used to constrain free inertial drift during times of poor GNSS visibility. The filter also contains a state for modeling the circumference of the wheel as it may change due to hardware changes or environmental conditions.

The modeled wheel circumference is available in the WHEELSIZE log. Information on how the wheel sensor updates are being used is available in the INSUPDATE log.

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SPAN-IGM User Manual Rev 2

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Novatel OM-20000141 user manual Span Wheel Sensor Messages, Measurement Timing and Frequency, Wheel Sensor Update Logic
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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.