SPAN Operation

Chapter 3

6.Alignment is complete and the INS Status field changes to INS_ALIGNMENT_COMPLETE. The system transitions to navigation mode.

7.The solution is refined using updates from GNSS. Once the system is operating within specifications and after some vehicle movement, the INS Status field changes to INS_SOLUTION_GOOD. This indicates that the estimated azimuth standard deviation is below 5 degrees. If it increases above 5 degrees, the status changes to INS_HIGH_VARIANCE.

The azimuth standard deviation threshold can be changed using the INSTHRESHOLDS command. See the SPAN on OEM6 Firmware Reference Manual (OM-20000144) for information about this command.

3.2.1.1Kinematic Alignment

A kinematic alignment is the default alignment routine for SPAN-IGM. The kinematic or moving alignment is performed by estimating the attitude from the GNSS velocity vector and injecting it into the SPAN filter as the initial system attitude.

This method for alignment assumes that the roll and pitch of the vehicle are near to zero. This should be kept in mind when attempting to do this in airborne or marine environments as these assumptions may not hold causing a poor initial solution. For the kinematic alignment routine to work optimally, the course- over-ground azimuth and pitch must match the SPAN-IGM enclosure azimuth and pitch. (For example, a plane being blown in the wind has a a large ‘crab angle’ and the course-over ground trajectory will not match the direction the SPAN-IGM is pointing.)

To enable kinematic alignment on the SPAN-IGM, assumptions about the system orientation have been made in the firmware. The default orientation of the system assumes the Z-axis of the enclosure is pointing up and the Y-axis of the enclosure is aligned with the forward axis of the vehicle. If these assumptions are not true, additional setup commands must be sent before attempting a kinematic alignment.

If the Z-axis is not pointing up, the correct axis orientation must be specified using the SETIMUORIENTATION command. Refer to Table 7, Full Mapping Definitions on page 43 for possible configurations and the SPAN on OEM6 Firmware Reference Manual (OM-20000144) for details about the command. If the Y-axis of the system is not aligned with the forward axis of the vehicle after the orientation is applied, then the VEHICLEBODYROTATION command must be sent. Refer to the SPAN on OEM6 Firmware Reference Manual (OM-20000144).

Alternatively, solve the vehicle to SPAN-IGM frame angular offsets using the RVBCALIBRATE routine. See Vehicle to SPAN Frame Angular Offsets Calibration Routine on page 33.

The kinematic alignment begins when the receiver has a good GNSS position, fine time is solved, the configuration parameters have been set and a GNSS velocity of at least 5 m/s (~ 18 km/h) is observed. During kinematic alignment, keep the vehicle roll at less then 10°. Straight line driving is best.

The accuracy of the initial attitude of the system following the kinematic alignment varies and depends on the dynamics of the vehicle and the accuracy of the RVB estimates. The attitude accuracy will converge to within specifications once some motion is observed by the system. This transition can be observed by monitoring the INS Status field in the INS logs.

3.2.1.2Manual Alignment

If the initial attitude (roll, pitch, azimuth) of the SPAN-IGM is known, it can be entered manually using the SETINITATTITUDE command. Refer to the SPAN on OEM6 Firmware Reference Manual (OM-20000144).

3.2.1.3Dual Antenna Alignment

SPAN-IGM can also use information available from a NovAtel Dual Antenna ALIGN® solution to perform an alignment. Refer to Chapter 4, SPAN-IGM Dual Antenna on page 38 for details.

SPAN-IGM User Manual Rev 2

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Novatel OM-20000141 user manual Kinematic Alignment, Manual Alignment, Dual Antenna Alignment
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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.
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