PCMaster Tutorial: Create the Point Cloud

The PCMaster Pre-Processing Software generates a calibrated point cloud.

PCMaster Pre-Processing Software Workflow

1. Complete a flight with the R2A or R360.
2. Transfer the data from the USB drive to your processing computer.
3. Transfer the RINEX data from the RS2 to your processing computer.

R2A Project Folder and Files Contents

The files located in the project folder transferred from your USB data will contain the following:

• data  folder - contains all the raw LiDAR data and photos
• ppk PCMaster file - project file to start PCMaster 
• ppk PCPainter file - project file to start PCPainter
• service log - contains system log information

Base Station Files Contents

Copy the RINEX data folder from the RS2 into the "data" folder of the project folder.

• NAV
• OBS
• Any RINEX format: .22o, .22n, .22g, .22l

Creating Your Point Cloud

1. Start PCMaster

• Double click ppk PCMaster Project file

PCMaster will open a New Project and create several folders in the project folder:

• camera - raw photos
• ins - inertial and navigation data
• lidar - point cloud data 

2. Select Base Station file

A prompt "Base measurements file was not found" will appear.  Enter the base station file: 

• Select the RINEX observation file (.22o)
• PCMaster will now convert the raw RINEX data

3. Base Station Coordinate Reference System

Next, a prompt will appear for the base station coordinate

• Latitude, Longitude - enter WGS84
• Ellipsoid Height - Enter the height of the tripod plus the phase center offset

4. Click OK to Begin Processing GNSS Trajectory

You will see the following graphs while the GNSS Trajectory is processing. This information helps determine your final point cloud. See below for the information contained in each graph. 

• The GNSS Position Quality graph above plots the East, North, and Vertical separation of the forward and reverse trajectories
• It's normal to see a spike in separation during the takeoff and landing, everything will become fixed during the flight.

 

• The IMU Antenna Lever Arm Refinement graph will run several times and it will appear thinner after each iteration, indicating an accurate level arm.

Processing tightly coupled UAV trajectory

• The Forward/Reverse Attitude Separation graph  calculates the attitude separation for heading, pitch, and roll.

5.  Point Cloud Creation

• PCMaster will automatically begin to load the trajectory and lidar files and will populate the visualizer with the point cloud.

To navigate the point cloud:

• CTRL + Click and Drag - translate the point cloud
• SHIFT  + Click and Drag - rotate the point cloud
• CTRL + SHIFT + Click and Drag - raise or lower the point cloud

 

6. Remove Flight Paths

• Click Paths tab and then click Remove

7. Select Flight Paths

• Right-click at the blue end of the trajectory (after your flight calibration procedure) and select Start selection here

• Right-click at the red end of the trajectory (at the end of your planned mission) and select Finish selection here

Your first selection will now look like this:

8. Cloud Filters

To improve the accuracy of the point cloud we trim off points by using the rotation angle and distance filters. 

Rotation Angle - For the R2A setting the Rotation angle filter to 237 - 303 will improve the resulting point cloud slightly.

Distance - Set your distance filter to ignore laser returns that are either too close to the sensor or too far away. This is dependent on your flight plan but generally you will want to ignore points that are closer than 3-8 meters and ignore points that are greater than 200 meters from the sensor.

9. Create Your Final Point Cloud

• Click Produce LAS and save the project when asked.
• PCMaster will create a clouds folders and save the point cloud.

Step 9: Colorize your Point Cloud

• Watch the tutorial on how to use PCPainter to colorize your point cloud

Have more questions about this topic? Visit community.rockrobotic.com to create a post to ask questions and connect with other community members as well as the ROCK Support Team.

Use the navigation menu below to continue the tutorial.