Table of Contents

How to process a MS-96 pedestrian outdoor backpack scan

This tutorial describes, end-to-end, the steps to obtain exploitable data. Parameters can be changed by advanced users with specific needs. It assumes that the software is already installed and the working directory is set.

Open PPIMMS

Double click on the icon on your desktop to open PPIMMS.

PPIMMS will open.

Create an environment

Click on “File” -> “New environment”.

Click on the right icon.

Type a name. Do not change the location or the format. Click “Save”.

Then click “Add”.

Create a project

Give a name to the project.

Then click “Add”.

Import an acquisition

Click on “Import AAR”.

Click on “Browse” and look for an AAR file that you exported from the system.

Select the AAR file and click on “Open”.

Click on “OK”.

This AAR file will be unzipped and added to the acquisition folder of the software working directory.

Left click to select the acquisition and then click “Add Acquisition To Project”.

Synchronization/Preprocessing

From PPIMMS 2.27.27, this step is called preprocessing as it allows to help for future computations (SLAM and loop algorithms in particular).

A pop-up window opens up, asking you to synchronize/preprocess the acquisition. Click “OK” to confirm and launch the synchronization/preprocessing.

The synchronization/preprocessing will run.

Once the Synchronization/Preprocessing is done, the environment will open.

Activate the project

Right-click on the project name and click on “Set as active”.

The project will open.

Odometric Trajectory Computation

From the post-process menu click on “Odometric Trajectory Computation”.

Use the default settings (as follows).

Default settings.

Click “OK” twice to launch the computation.

Add Loop Constraints

From the post-processing menu, click on “Loop constraints”.

Use the default settings.

Default settings.

Left-click “OK” twice to launch the computation.

Add Navigation Constraints

Open Qinertia

Open Qinertia.

Click on “New Project”.

Create a project in Qinertia

In “Project name”, give a name to your project.

In “Organization” write the name of your company.

Under “Save Project”, choose (if not already done) the working directory of the software. We recommend having one folder called Qinertia on your main SSD drive and never changing this parameter.

Under “Import Files”, left-click on “browser” to open an explorer. Navigate to the session folder exported from the MS-96 (or the acquisition folder in the PPIMMS working directory if you do not have access to the session folder). Then click “Select Folder”.

Then click “Next”.

Configure the project in Qinertia

Activate “Geodetic Configuration” by clicking on the toggle icon.

Click on the search icon on the right for the line “Project Coordinate System”. 

A window opens. In the top field, look for the EPSG / CRS name that you want to use to reference the GNSS data.

Then click “Select” on the bottom right.

Back on the first window with the motion profile, click “Next”.

On the “Data sources” page, click “Next”.

On the “Trajectory preview” page, click “Next”.

If a warning appears, click “Yes”.

On the “Base stations” page, wait for Qinertia to find a base station (visible at the bottom left under “Processing details”). If Qinertia creates a Virtual Base Stations out of a network, you will need to validate the network. Simply accept and move on. Click “Next”.

On the “IMU Model” page, click “Next”.

On the “IMU Installation” page, click “Next”.

On the “IMU Lever Arms”, click “Next”.

On the “GNSS Setup” page, in “Antenna type” (middle right of the page), look for the [VMTRS_MS96_1 NONE] antenna. Then click “Next”.

Your project is now configured. Click “Finish”.

GNSS PPK computation in Qinertia

The main Qinertia interface will appear.

Click on the satellite icon, then “PPK”.

Wait for the computation to be completed. The “Processing summary” appears.

Export data from Qinertia

Click on “File”, then “Exports”.

Click on the “PPIMMS_PPK_Geodesy” profile. If not done, in the field “Output data better than”, choose “RTK/PPK/PPP Fixed” in the list. Then click “Launch export” on the bottom right.

Wait for the document icon to have a complete 360 blue stripe around it. The file has been exported to an \export folder in the Qinertia project folder. You can now close Qinertia.

Import result in PPIMMS

Go back to your activated PPIMMS project.

In the “Post Process” menu, click on “Navigation Constraints Computation”. Open the settings. Next to the first line “External File Name” click on the icon to open an explorer.

Navigate to the exported file from Qinertia, click on it and then on “Open”.

The lever arm must be “GNSS”.

Both the External File EPSG Code and Projection (EPSG Code) must be the code of your chosen projection (the one chosen in the “Geodetic Configuration” in Qinertia).

Click “OK” to validate your settings and “OK” to launch the computation.

Once the computation is done, it is normal that the point clouds disappear from the viewer. It has just shifted to the new coordinate system. To reach it, unfold the “Trajectories” items in the tree structure, right-click on the “Minimized Trajectory” and choose “Center View On”.

Add Ground Control Points

This step only applies if you have GCPs to add. Discard if not.

From the post-processing menu, click on “Add Block Constraints”.

It will open a window on the right side of the screen.

Select the “GCP” mode.

Choose the EPSG of the coordinates reference system your GCPs are expressed in.

Click as accurately as possible on the point of the point cloud that should have the GCP coordinates.

Write the coordinates in the XYZ fields available.

Set the confidence level to:

  • “Full” if you can click the point with accuracy,
  • “Intermediate” if you cannot.

Click “Add” then “Validate”.

Click “OK” to confirm the change of ESPG code of the project if a window appears.

Then repeat the operation if you have other GCPs to add.

Global Optimization

From the post-processing menu, click on “Global Optimization”.

Click “OK” to launch the computation.

Create Result

From the post-processing menu, click on “Create Result”.

Click “OK” to launch the result creation.

A new item called “Result” will appear in the tree view on the left.

Edit Mask/Color

Unfold the Result item and “Media Data”. Right-click on “MultiCams” and then on “Edit Mask/Color”.

A window will open. You can increase its size and increase the camera stream viewer by zooming using the wheel.

In the “Color/Tonal” tab, you can adjust the white balance and “Gamma” if needed.

To adjust the white blance check “White balance”, then click on the pencil. Then right click on a white object in a picture. The RGB values will adjust accordingly.

To adjust the gamma, check “Gamma correction” then change the value. To 2 for instance to have more light in the picture.

Go to the “Mask Editor” tab. From the list on the bottom left, go to the “FrontLeft” camera. Using the right-click, draw a contour around the operator head and shoulder. Then click “Apply”.

Using the right-click, draw a contour around the operator head and shoulder. Then click “Apply”.

Repeat the operation for the “BackRight” camera, not forgetting about contouring as well the lidar.

When finished close the window.

Unified Point Cloud Export

For all users of PPIMMS 2.27.27, we recommend the use of the unified point cloud export. This functionality is a all-in-one process that embeds point cloud colorization, filtering, combination of side and top lidar, spatial decimation and RGB layer homogenization. It will provide higher quality results than the previous historical workflow (colorization -> filtering -> export).

In the Result menu, select Export PointCloud (Unified) and then the result.

Double click or select the line and click on Settings.

Choose your format or leave by default.

Type the output file name or leave by default.

Choose the environment type:

  • “Narrow Indoor” will cut the range at 10-15m,
  • “Hybrid” at 25-30m,
  • “Long Range” at +50m.

For outdoor scans we recommend using “Hybrid”, or potentially “Long range” for specific projects where a longer range is needed.

Choose your resolution to homogenize the point cloud:

  • High: 5mm
  • Standard: 10mm

Please note that these values only give an approximation of the point cloud density. There will be points closer to each other than the expected values.

When satisfied with the settings, press OK twice.

The process will start, finishing with a link in the console to the exported finalized point cloud in the chosen format.

Historical finalization workflow

This historical workflow splitting colorization, filtering and export can alternatively be used by users who do not have at least PPIMMS version 2.27.27 or with special needs. It is however not recommended and provide less qualitative results.

Colorization

From the menu “Result”, click on “Colorize Point Cloud” and choose the result to colorize.

Select the result line and click on “Settings”.

Choose the following settings.

The colorization process will then run.

Noise Filtering

From the menu “Result”, click on “Filter Point Cloud” and choose the result to filter.

Select the result line and click on “Settings”.

Choose the following settings.

The filtering process will then run.

Point Cloud Export

From the menu “Result”, click on “Export point cloud” and then the result to export.

Select the result line and click on “Settings”.

Choose the following settings.

Confirm and launch the export by clicking on “OK” twice.

The export process will then start running.

The colorized and referenced point cloud is now available and can be used in third party software.

Images Export

From the menu “Result”, click on “Export Images”.

Then click on the result to export.

Choose the following settings.

Please note that you can choose another format for the camera trajectory depending on the third party software that you will be using.

  • XYZ: Orbit GT suite, VisionLidar, Cintoo, AtisCloud, PointCab, Benaco, SCC
  • CSV: e-Cassini
  • TopoDot: TopoDot

Confirm and launch the export.

The panoramic images are then available and can be used in third party software.