Chapter 3

 

SPAN Operation

 

 

 

 

Table 4: Inertial Solution Status

 

 

 

 

 

 

Binary

ASCII

 

Description

 

 

 

 

 

 

0

INS_INACTIVE

 

IMU logs are present, but the alignment routine has not started;

 

INS is inactive.

 

 

 

 

 

 

 

 

 

 

 

1

INS_ALIGNING

 

INS is in alignment mode.

 

 

 

 

 

 

 

 

 

 

 

The INS solution is in navigation mode but the azimuth solution

 

 

 

 

 

uncertainty has exceeded the threshold. The default threshold is 5

2

INS_HIGH_VARIANCE

 

degrees.a The solution is still valid but you should monitor the

 

 

 

 

 

solution uncertainty in the INSCOV log. You may encounter this

 

 

 

 

 

state during times when the GNSS, used to aid the INS, is absent.b

3

INS_SOLUTION_GOOD

 

The INS filter is in navigation mode and the INS solution is good.

 

 

 

 

 

 

 

 

 

 

 

The INS filter is in navigation mode and the GNSS solution is

 

 

 

 

 

suspected to be in error.

6

INS_SOLUTION_FREE

 

This may be due to multipath or limited satellite visibility. The

 

 

 

 

 

inertial filter has rejected the GNSS position and is waiting for the

 

 

 

 

 

solution quality to improve.

 

 

 

 

 

 

 

 

 

 

 

The INS filter is in navigation mode, but not enough vehicle

7

INS_ALIGNMENT_COMPLETE

 

dynamics have been experienced for the system to be within

 

 

 

 

 

specifications.

 

 

 

 

 

 

8

DETERMINING_ORIENTATION

 

INS is determining the IMU axis aligned with gravity.

 

 

 

 

 

 

9

WAITING_INITIALPOS

 

The INS filter has determined the IMU orientation and is awaiting

 

an initial position estimate to begin the alignment process.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

a.This value is configured using the INSTHRESHOLDS command. See the SPAN on OEM6 Firmware Reference Manual (OM-20000144) for more information.

b.See also question #4 in Appendix B, Frequently Asked Questions on page 60.

3.2.1System Start-Up and Alignment Techniques

The system requires an initial attitude estimate to start the navigation filter. This is called system alignment. On start-up the system has no position, velocity or attitude information. When the system is first powered up, the following sequence of events happens:

1.The first satellites are tracked and coarse time is solved.

2.Enough satellites are tracked to compute a position.

3.Receiver “fine time” is solved, meaning the time on board the receiver is accurate enough to begin timing IMU measurements.

4.Raw IMU measurements begin to be timed by the receiver and are available to the INS filter. They are also available in the RAWIMU, RAWIMUS, RAWIMUX, and RAWIMUSX logs. The INS Status field changes from INS_INACTIVE through DETERMINING_ORIENTATION and WAITING_INITIALPOS during this period.

5.The inertial alignment routine starts and the INS Status field reports INS_ALIGNING.

For information about the methods used to complete the alignment routine, refer to the alignment modes described in the following sections.

•Kinematic Alignment on page 31

•Manual Alignment on page 31

•Dual Antenna Alignment on page 31

30

SPAN-IGM User Manual Rev 2

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Novatel OM-20000141 user manual System Start-Up and Alignment Techniques, Ascii
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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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