Introduction
Qinertia features a powerful module used to estimate and refine automatically mechanical installation parameters such as the GNSS primary and secondary antenna lever arms. You can use this module if you have no way to precisely measure lever arms or alignment but also to check entered settings consistency.
The automatic estimation algorithm needs enough dynamics and good GNSS conditions to observe correctly the lever arms. Please read the dedicated Lever arms & alignment calibration article to get more details.
Project Settings
Qinertia can estimate several mechanical installation parameters such as GNSS antennas lever arm, odometer lever arm, DVL alignment and lever arm. You first have to configure the project correctly to indicate which parameters have to be estimated and which have been entered accurately and don't need to be estimated.
This is done from the INS Project Settings in each aiding panel. The screenshot below illustrates this for GNSS aiding and you can indicate if the primary and secondary GNSS lever arms have to be estimated or not.
Rough lever arm
Even if Qinertia auto estimation module is very powerful, try to enter initial lever arm guess as close as possible to real values to improve estimation robustness and quality.
Process the mission
When you start an INS processing, Qinertia will enable the automatic estimation for each parameter that has been indicated as being not accurate. During this specific processing, Qinertia will try to estimate the mechanical installation parameters and report the refined lever arms with associated quality metrics. The screenshot below shows the results for a GNSS primary and secondary lever arms estimation.
The default display shows easy to understand quality metrics computed using the estimated parameter standard deviation and stability. If you click on the Quality label, you can access these advanced metrics as shown on the screenshot below:
Apply the estimated parameters
During the auto estimation processing, Qinertia focus on lever arm estimation and not on the INS solution accuracy and reliability. You shouldn't use the INS solution that has been computed for the automatic estimation but rather launch a new processing with the lever arms refined by Qinertia.
If you are happy with the estimated lever arms and alignments, simply check the use checkbox to update the project configuration with the new values. You can then launch right away the final INS computation or close the dialog box and do it later by yourself
