General Layout

The following screen shows the main Qinertia window for a processed project. In this example, the trajectory display, a pie chart of the INS solution type, the INS altitude and statistical data on the orientation accuracy are displayed.

Main Tool Bar

Please find below the description of each main tool bar icon:

Open new time series such as the INS solution altitude or roll/pitch/heading values.

Open a new trajectory display map. This can be useful if you would like to view side by side the origin and post processed solution.

Open a statistical quality indicators such as the solution type or the position accuracy and separation.

Shows the list of log messages output by Qinertia application itself.

Open the GNSS base station management dialog box.

Open the dedicated photogrammetry module to match pictures to events.

Access the project configuration such as GNSS lever arms or processing options.

Display the data coverage and also let you crop the log.

Shows the list of messages that have been produced by the INS during the acquisition.

Open Qinertia application settings such as network settings and GNSS providers list.

Start INS processing, you can select the processing mode to use according to the project configuration.

Start GNSS only processing. You can select the processing mode to use according to the project configuration.

Select the active dataset to use when a new time series or the trajectory display is opened.

Time line and status

The time line is located at the bottom and is used to navigate easily within the mission. This area also displays several information such as the current time, the processing status and so on.

qinertia-time-line

Overview

Please find below the description of each item:

ADisplays the current cursor time in seconds. You can display a GPS Time of Week as shown in the example above or a time stamp.
BDisplays the current cursor GPS date and time.
CDisplays the current cursor GPS Week number.
DIf you have selected the GPS Time of Week display for A, it displays the current cursor time stamp. Otherwise it displays the GPS Time of Week.
E

Indicate the clock status from the INS if available. You can have the following labels:

  • Clock Valid: Time is valid and aligned to GNSS time.
  • Clock Warning: Time is not actively aligned by GNSS time. It can occurs in case of long GNSS outages and the INS clock can drift over time.
  • Clock Error: The time is not available or not aligned to GNSS time. You may experience issues and decreased accuracy.
FThe total log duration after the log has been cropped in hh:mm:ss.sss
GIf a processing has been launched, displays the current progress and processing result.
HTime controls to easily move within the log and also to crop the log.
IThe timeline itself, you can move the current cursor time, zoom in / out the time and pan the displayed time window.
JLatest selected time cursor that is not updated until you click the lest mouse button.
KCurrent time cursor at which information are displayed such as values in time series and updated by a mouse hover.
LMaster switch to discard all user defined manual aiding rejections.

Processing status

These icons are only displayed if you have processed a log. If you click on the icons, you can show processing status and information details. Also a color code is used to shows as the processing is being done the quality and status.

In this area, you can see the following status:

Displays export jobs progress and status. You can click on it to show current and passed export jobs. You can for example easily open the directory where data has been exported to.

Shows the GNSS pre-processing progress & status and in this example, the yellow color indicates we have a warning. Click on it to display the pre-processing report to get more details.

Shows the forward computation progress & status. The color indicates as the log is being processed the solution quality.

Shows the backward computation progress & status. The color indicates as the log is being processed the solution quality.

Shows the merged computation progress & status. The color indicates as the log is being processed the solution quality.

Using the timeline

Qinertia unique user experience comes from the way time is managed and how easy it is to navigate trough the mission to finely analyze the log. Qinertia offers several tools and interactions to make this task intuitive and powerful.

Qinertia keeps all displays and the timeline synchronized so if you zoom in/out in time or move the current time cursor, it is reflected in the plots, the trajectory display and of course the timeline control.

It also works the way around, for example, if you move the current cursor in the trajectory display the time line cursor is updated accordingly.

Time controls

The time controls buttons are located next to the time line itself. They offer the most basic way to navigate precisely within the log. Please find below the description for each button:

Jump to the beginning of the log

Move one epoch backward

Start/stop playing the mission

Move on epoch forward

Jump to the end of the log

Jump to a specific time / epoch

Crop / uncrop the log, the data is never lost

Navigate in the timeline

You can navigate in the timeline from different displays even if the most straightforward one is the timeline control itself.

The current time is represented as an orange bar and the selected current time as a dashed orange bar in the timeline control and the time series plots. The trajectory map display uses the icon  to represent the position at the current time as shown in the screenshot.

Please find below the list of actions to navigate in the timeline:

  • Temporary move the current time cursor by hovering the mouse over the timeline
  • Select a new current time cursor by clicking the left mouse button in the timeline or any plot
  • Zoom in/out in the displayed time window with the mouse wheel over the timeline control
  • Pan the displayed time windows using the mouse right button in the timeline control
  • Pan the displayed time windows using the mouse left button in time series plots

Time cursor

If you mouse hover the timeline control, you can temporary move the current time cursor without loosing the latest selected time cursor. This is very helpful to quickly review quality indicators near a selected time/position.

Time line selections

You can select a time span to zoom on it, compute quality indicators only on the selected span, define which part of the log has to be processed or exported and even define manual aiding rejections areas. A time span selection is represented with a translucent orange area as you can see in the screens below.

Qinertia offers several ways to select a time span:

  • In the timeline control, simply click and hold the mouse left button
  • In time series plots, you have to hold the shift key and then click and hold the mouse left button
  • In the trajectory display, clock and hold the mouse left button over the trajectory
  • In the trajectory display, you can hold the shift key and then click on the trajectory. It will select a time span from the current cursor to the selected point.

Once you have selected a time span, you can right click on it to perform the following actions:

  • Zoom on interval: The displayed first and last time are set to the selected time interval. This is very helpful to easily focus on a part of the log.
  • Define as analysis span: Statistical analysis such as solution type pie chart will be computed only on the selected time interval. Once the analysis span is defined, it is represented by a blue area in the timeline control.
  • Define as export span: Define which part of the log has to be exported. Once the export span is defined, it is represented by a read area in the timeline control.
  • Define as rejection span: Create a new rejection area to forbid the INS to use some or all aiding measurements such as GNSS position, dual antenna and so on.
  • Define as Processing span: Crop the log to only process the selected area. It has the same action as the crop icon button and you have to go to the data coverage dialog box to modify or remove this crop.

Analysis & Export span

You can reset at any time the analysis or export span by right clicking on the span area in the timeline control and select the Reset contextual menu option.

Dataset

Qinertia can display several dataset such as the real time INS solution, the forward or backward only solution and of course the final merged solution. It can be very interesting to display and compare each solution for quality control and troubleshooting.

It is also possible to export data from a specific dataset. You can for example, export the real time INS solution and the post processed merged solution very easily.

Dataset selection

You can select the active dataset from the toolbar icon or from the Project→Dataset menu. Please find below the list of available dataset:

  • Auto: This is the default selection, Qinertia will pickup automatically the dataset that has the best accuracy. It will thus be origin until you process the data to become forward when you start the processing. Finally the merged solution is selected when the processing is completed.
  • Origin: This dataset stores the real time INS or GNSS only solution. The data is available only if the be available for all SBG Systems INS and for some third p
  • Forward: This dataset displays the forward only solution. If you launch a reprocessing, it will be the only available solution. If you launch a post processing, Qinertia will compute the forward and backward solutions before merging both to get best accuracy.
  • Backward: This dataset displays the backward only solution. It contains data only if you have launched a post processing computation.
  • Merged: This is the final post processed result that offers the best accuracy and the smoothest solution. The forward and backward solutions have been merged together to produce this accurate solution. It is the one you should export and use.

Each time you open a new panel such as a time series, the trajectory display or even statistics displays such as pie charts and histograms, Qinertia will use the currently selected dataset. For example, if you select origin, and open the trajectory map, you will see the real time INS solution if available. You can thus select back Auto and open a new trajectory display to compare the real time and post processed trajectories.

It's the same to export data. Simply select the dataset you would like to export and then start the export job.

If you have selected manually a dataset and then export data, Qinertia will ask you to confirm you choice. This is helpful to avoid user mistakes following quality control that has involved dataset switches for instance.

Example

The following example shows the same position standard deviation plot two times. On the left, we see the real time INS solution position standard deviation and on the right the post processed tightly coupled merged one.

The user has simply selected the origin dataset and then opened the position standard deviation to get the left plot. The right plot has been opened while the auto dataset was selected that is the post processed merged solution. As you can see in the screenshot below, the dataset displayed in a panel is indicated in the title.

The example below clearly demonstrate the benefit of post processing. We are comparing a real time INS solution that was receiving RTK corrections with the tightly coupled one and during GNSS outages the maximum error decreases from up to 1.7 meters to less then 18 cm.

qinertia-dataset

Trajectory Map

Qinertia features a user friendly trajectory map display that can be used to assess the processed solution quality. This display renders all the epochs of the trajectory so if you have INS data at 200 Hz, you can view all these points in real time. It is much better than traditional 1Hz displays typically used by competitors as you can finely analyze the INS behavior and look for any artifact.

Moreover, the trajectory map features several graphical indicators and displays modes to ease quality assessment task.

Understanding the display

In the screenshot below, you see a typical INS solution in harsh GNSS conditions. The INS solution is displayed using a plain green line, the real time GNSS positions are displayed using yellow dots. The current INS solution is represented by the white marker and a very small green ellipse, that is barely visible in this example, represents the INS accuracy. The real time GNSS solution accuracy, that was receiving RTK corrections, is also displayed graphically using the red ellipse and we clearly see the benefit of the INS other a standard RTK GNSS receiver.

Quality display modes

The trajectory can be displayed using two modes.  By default, the solution quality is represented using a color code from green to red and is based on the estimated position standard deviation as shown in the screen above. Qinertia can also display the trajectory using a color code for each position type also called fix type as shown in the screenshot below:

A position type defines how the solution has been computed such as PPK Fixed, PPK Float, odometer, pure inertial, ... In the screenshot above, we see the INS solution is in PPK Fixed before the bridge and then is using velocity constraints under the bridge before going back to PPK float between the two bridges. The color code is the same as the one used in the Position Type pie chart so please refer to it to get the color code legend.

Using the map display

You can easily navigate in the map display using the mouse left button. If you would like to zoom on a specific area, you can either use the mouse wheel or draw a box using the mouse right button.

If you place your mouse hover the INS trajectory or a GNSS solution (yellow dot) you can access detailed information about the accuracy and quality.

The map display also features the following action buttons:

Access the layer options to change the map background, show/hide some data such as the GNSS solutions and most importantly switch between quality color code to position type color code.

Center and fit the map display on the whole trajectory.

Take a screenshot of the current map display.

Enable the distance measurement tool. Once opened, simply left click to select the distance to measure.

Center and fit the map display on the base station used in the processing.

Dataset selection

You can open several trajectory maps if you would like to easily compare the origin (real time solution) and the post processed merged solution for example. Simply select the dataset you would like to display and then open a new trajectory map panel.

Time Series Plots

Qinertia is able to display a lot of time dependent plots such as the INS altitude or Euler angles. These plots are also called time series and can be opened from the toolbar icon or the View→Add Graph menu.

Time series plots are able to display the data at high frequency and if you zoom enough in time, you can view each measurements at up to the IMU rate (ie 200 Hz for SBG Systems INS). This is very helpful to finely analyze the data and the solution quality.

The time series plot offer several interactions to ease data analysis:

  • Move within the plot using the mouse left button. If you move on the X axis, it will change the displayed time window that is synchronized across all displays and the time line itself.
  • Use the mouse wheel or the + and - keys to zoom in/out the Y axis scale. It will not change the X axis scale that is controlled by the timeline itself.
  • Draw a box using the right mouse button to zoom in the Y axis scale.
  • Hold the shift key and use the left mouse button to draw a time selection (orange) and then right click on it to adjust the displayed time window to it. This interaction is illustrated below and is explained in the time line section.
  • You can hide or show each graph component by simply clicking on the legend on the right
  • The current selected time is represented using a vertical orange bar and, on the right, you see the components exact values at that time.

Dataset selection

You can open several time series plots if you would like to easily compare the origin (real time solution) and the post processed merged solution for example. Simply select the dataset you would like to display and then open a new plot.