kaarta STENCIL 2 User manual

WWW.KAARTA.COM
USER GUIDE

2
INTRODUCTION
Congratulations on the purchase of Kaarta Stencil®2. In this document you will find complete
instructions to use Stencil 2 from initial set up to mastery. You’ll learn to operate the scanner,
interface with a computer, and to customize the parameters for best results. This guide also
covers GNSS operations, provides tips for optimum data collection, and gives detailed
instructions on working with point clouds.
This guide also answers questions with a list of Frequently Asked Questions and Case Studies.
With Stencil 2, comes a Kaarta Documentation Drive that contains a copy of this user guide,
training slides, the mechanical mounting interface plate dimensions, and the Circle_Centered.obj
file.
Visit our website for additional information and updates. www.kaarta.com
OVERVIEW
Kaarta Stencil®2 is a low cost, customizable mobile mapping platform for rapid mobile scanning;
a computer small enough to fit in your hand but powerful enough to process and view any of the
data it captures.
CARE
Like any precision instrument, take precautions to ensure a long, useful life of the device. Treat it
with care. Avoid rough handling, dust, and water exposure. Use the shipping case to protect it
during transportation.
SCOPE
These instructions are for Stencil 2 Software Version S2-20.02 with Ubuntu 16.04 installed.
Software Updates and Hardware Upgrades are available for all Stencils. Please email
[email protected] with the Stencil Serial Number for the best options for your
particular unit. See Release Notes for a summary of new features for Stencil 2 and a list of the
newest features included in this release. Older Release notes are at the end of this manual.

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RELEASE NOTES
Stencil 2 features exciting new enhancements to the User Interface, GNSS localization, mapping
accuracy, confidence metrics, Adaptive Data Replay, hardware, software, and data collection.
Below is an overview of the new features and their benefits. More details on each new feature is
provided throughout this guide.
NEW FOR SOFTWARE RELEASE S20.02 (FEBRUARY 2020)
Hardware
HDMI dummy
plug removal
Changes to the video settings in the BIOS for S/N >
150 allow Stencil 2 to operate without the need for
an HDMI dummy plug when using an iPad.
Performance
Improvements
Improved loop
closure
More accurate correction of Stencil trajectories
based on GNSS data. Automatic determination of
physical and temporal offsets used for loop
closure.
Improved scan
matching
algorithms
Many improvements in live scanning and Adaptive
Data Replay to yield better point clouds and
trajectories.
Easier
localization
Localization map is displayed prior to moving for
quicker identification of initial pose.
Improved
data post-
processing
CCC Builder
(Alpha Release)
New Tool to perform CloudCompare operations
without using CPU resources for visualization
LAS file generator
Export a binary LAS file from a Stencil point cloud.
LAS file merging
Easier merging of multiple LAS files with GNSS data
Additional scalar
fields for point
clouds
More scalar fields are now available for improved
visualization, cleaning, and editing of point clouds
(including range, normals, curvature, noise filtering
values, and confidence).
Additional
cleaning options
Two new filters have been added to remove
moving objects and clean / level point clouds
GNSS
PPK correction
pipeline
New post-processed kinematic (PPK) correction
pipeline utilizing CORS base stations.
Improved GNSS
integration
Intermediate trajectory file for direct comparison
of GNSS and Stencil trajectories. Stencil offsets are
now configurable for the Loop Closure Tool.

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NEW FOR SOFTWARE RELEASE S20.02 (FEBRUARY 2020)
Improved
information
stats and
tools to
increase
productivity
New automated
scripts
Many scripts have been added to clean,
manipulate, and improve point clouds,
interoperability, and processing.
Improved
reporting and
statistics
Improved error reporting, output stats from Loop
Closure Tool, more data in the scan_info files and
logging of Processor data during scanning / replay
to help debug customer issues.
Adaptive Data
Replay
Improved
interface
Ability to start, single step, pause at, and stop
replay from parameters. Standalone tool sets
Mapping/Localization and with/without camera
modes within the dialog box.
Kaarta Cloud
integration
Upload to Kaarta
Cloud
Enable uploading to Kaarta Cloud directly from
Stencil for processing.

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CONTENTS
Introduction .......................................................................................................................................2
Overview.........................................................................................................................................2
Care...............................................................................................................................................2
Scope ............................................................................................................................................2
Release Notes ................................................................................................................................3
Chapter 1..........................................................................................................................................10
Getting started.............................................................................................................................10
What’s in the Box ......................................................................................................................10
Getting to Know Stencil 2.........................................................................................................10
Getting to Know Stencil 2 - older units...................................................................................11
Status Indicator .........................................................................................................................12
Power/Operating Mode Buttons.............................................................................................13
Using Stencil 2 Out of the Box ...................................................................................................14
Before You Begin Mapping: .....................................................................................................14
Start Mapping............................................................................................................................14
Stop Mapping ............................................................................................................................14
Scan Folder Contents ...............................................................................................................15
Chapter 2..........................................................................................................................................18
Stencil 2 Operations....................................................................................................................18
It’s a Computer ..........................................................................................................................18
Using the iPad ...........................................................................................................................18
Desktop Icons............................................................................................................................20
Tool Icons...................................................................................................................................22
Mapping with the Feature Tracker..........................................................................................24
Feature Tracker Best Practice..................................................................................................25
Recording Color Images while mapping ................................................................................26
Using the Mode Switch Icons ..................................................................................................26

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Kaarta User Interface ...............................................................................................................28
File structure-mapping/localizing scans.................................................................................32
Localization................................................................................................................................34
Localizing based on a prior map overview ............................................................................35
Confidence Values ....................................................................................................................36
Chapter 3..........................................................................................................................................38
Tools for Additional Functionality .............................................................................................38
Loop Closure Tool.....................................................................................................................38
Sharpening Tool ........................................................................................................................38
Floor Planner Tool.....................................................................................................................39
Command Line tools ................................................................................................................42
CloudCompare Command Line Editor Tool (ALPHA VERSION) ...........................................49
Using point clouds from other programs ..............................................................................50
Chapter 4..........................................................................................................................................52
GNSS Operations.........................................................................................................................52
Integrating GNSS with Stencil..................................................................................................52
GPS Setup ..................................................................................................................................52
GNSS Monitor Status ................................................................................................................53
Syncing Stencil Clock to GNSS time ........................................................................................53
Finding the USB port on Stencil 2, if not known....................................................................53
Recording GNSS Raw Data to use for PPK Processing .........................................................54
Processing PPK Data.................................................................................................................54
Using the loop closure tool overview .....................................................................................55
Key Poses and Geo-locating point clouds..............................................................................56
Loop closure using confidence values ...................................................................................59
Running loop closure twice .....................................................................................................59
Loop Closure with GNSS Data .................................................................................................60
Loop Closure Tool settings ......................................................................................................60
GNSS Loop Closure Example...................................................................................................69

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Loop Closure Tool Effect ..........................................................................................................70
Using Separately Logged Data in the Loop Closure Tool.....................................................72
Using Non-GNSS Data for Loop Closure ................................................................................73
Chapter 5..........................................................................................................................................74
Case Studies.................................................................................................................................74
Case Study 1: Loop Closure Mapping without GNSS Data...................................................74
Case Study 2: Ground Vehicle Navigation..............................................................................76
Case Study 3: Air-ground Collaborative Mapping .................................................................77
Chapter 6..........................................................................................................................................79
Tips for Collecting Better Data...................................................................................................79
General.......................................................................................................................................79
Handheld scanning - Indoors ..................................................................................................80
Handheld scanning - Outdoors ...............................................................................................80
Vehicle Mounted Scanning ......................................................................................................81
Aerial Scanning..........................................................................................................................82
Request for additional Scanning Tips.....................................................................................82
Problems / Issues ........................................................................................................................83
.ply file error or non-generation .............................................................................................83
Sun glare ....................................................................................................................................83
Double registration...................................................................................................................84
Small rooms/narrow hallways.................................................................................................85
Reflections .................................................................................................................................86
Darker/Brighter Environments................................................................................................86
Using CloudCompare..................................................................................................................87
Visualization basics...................................................................................................................87
Colorize Point Cloud by Z-Coordinates ..................................................................................89
Colorizing the point cloud by time using scalar fields..........................................................90
Colorization scales and Intensity values ................................................................................91
Geo-locating point clouds ........................................................................................................94

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Cleaning and merging .ply files: ..............................................................................................96
Point cloud cleanup ..................................................................................................................96
Merging Point clouds................................................................................................................97
ICP Matching in CloudCompare ..............................................................................................97
Chapter 7........................................................................................................................................102
FAQ..............................................................................................................................................102
Appendix I ......................................................................................................................................108
Customizing Velodyne Wiring ..................................................................................................108
Wiring the Connector................................................................................................................108
Appendix II .....................................................................................................................................110
Mounting Stencil 2 ....................................................................................................................110
Appendix III ....................................................................................................................................111
Parameter Definitions...............................................................................................................111
Typical parameters to set ..................................................................................................... 122
Appendix IV....................................................................................................................................124
Working with ROS......................................................................................................................124
Mode switching commands.................................................................................................. 124
Start / Stop mapping using ROS commands ...................................................................... 124
Creating a reference map for localization .......................................................................... 124
Remote commands not supported ..................................................................................... 125
Coordinate transforms for localization ............................................................................... 125
Important localization topics................................................................................................ 126
Reporting global position during localization..................................................................... 126
Localizing based on current GNSS location........................................................................ 126
Sensor Calibration ................................................................................................................. 128
Ethernet................................................................................................................................... 128
Appendix V.....................................................................................................................................133
Replaying Stencil 2 Data ...........................................................................................................133
Replaying Bag files in localization mode ............................................................................. 135

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Appendix VI....................................................................................................................................138
Synchronize Computer to Stencil 2.........................................................................................138
Computer setup ..................................................................................................................... 138
Setup Ethernet connection to Stencil 2............................................................................... 138
Setting Computer to Stencil 2 ROS Master ......................................................................... 139
Echoing the Localization topic.............................................................................................. 139
Showing map, camera, and pose information using RVIZ................................................ 140
Synchronize Stencil 2-To-Computer Time........................................................................... 140
SSH to Stencil 2....................................................................................................................... 141
Mapping and Localization Confidence ................................................................................ 141
Appendix VII...................................................................................................................................142
Troubleshooting ........................................................................................................................142
Appendix VIII..................................................................................................................................143
Previous Software Release Notes............................................................................................143

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CHAPTER 1
GETTING STARTED
WHAT’S IN THE BOX
GETTING TO KNOW STENCIL 2
1. iPad 10.2 inch display, 32GB RAM, and Wi-Fi dongle for wireless display and operation
2. AC charger for Stencil 2
3. Stencil 2 with Tripod Mounting Plate
4. Feature Tracker
5. Velodyne Lidar Sensor, including documentation on the Kaarta USB drive
6. Velodyne Interface Box, AC Supply, and country adapters (not shown)
7. Battery Pack - 23,000 mAH (US shipments only)
8. Battery Pack Charging Accessories (Use this charger only for battery charging)
9. Feature Tracker Cable (Installed)
10. Velodyne Inline Connector (Installed)
11. USB Status Indicator
12. Kaarta documentation on the Kaarta USB3 Drive (not shown)

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GETTING TO KNOW STENCIL 2 - OLDER UNITS
S/N’s between 100 – 150 [S/N’s between 1 -99 in square brackets]
1. Feature Tracker Connector
2. Power Input
3. Power Input Operating Switch (left button)
4. HDMI Port [miniDisplayPort]
5. Velodyne Connector Port
6. Ethernet Port (RJ-45)
7. Velodyne Switch (right button)
8. Two USB3 Ports (back)
9. Thunderbolt Port [HDMI, miniHDMI]
10. Two Air Vents
11. MicroSD card slot [No MicroSD card slot on S/N’s < 100]
12. Two USB3 Ports (front)
13. Feature Tracker
14. Velodyne Lidar Sensor

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STATUS INDICATOR
Stencil 2 comes with an USB LED Status Indicator. This indicator shows the state of the device
and provides alerts in the event of errors. Refer to the table below for definitions of indicator
color and states.
USB STATUS INDICATOR CODES
Color
State
Indication
Blue
Steady
System is ready
Green
Steady
Mapping/Localization initiated, wait about 20 seconds for the
Indicator to start blinking
Green
Blinking
Mapping/Localization in progress. It is best to wait about 5
seconds after blinking starts before moving
Teal
Steady
With GNSS: Mapping/Localization initiated, wait about 20
seconds for the indicator to start blinking
Teal
Blinking
Mapping/Localization in progress and GNSS data is saving. It is
best to wait about 5 seconds after blinking starts before
moving.
Note: When using GNSS, teal denotes a fix quality 1 or more
during mapping or localization. If the fix quality is 0, the light is
Green, and no points are saved in the GPS.ply. The indicator may
change between teal and green throughout the data collection.
Yellow
Blinking
Down sampling and saving point cloud
Magenta
Steady
Hard disk has < 50 GB left
Magenta
Blinking
Hard disk has < 25 GB left
Red
Steady
Mapping/Localization has not started within period set in
parameter file. This is typically due to a hardware issue such as
Velodyne not running, Feature Tracker not on in Mapping /
Localization mode with camera, or IMU is not running. If
problem persists, try rebooting Stencil.
Red
Slow Blink
Hard disk has < 10 GB left, cannot proceed
Red
Rapid
Blink
Expired license

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POWER/OPERATING MODE BUTTONS
On the back of Stencil 2 are two buttons for Stencil 2 and for Velodyne Lidar. The left power
button serves two functions for Stencil 2: Power ON/OFF and Start/Stop mapping or localization.
The right power button is for the Velodyne Lidar Power ON/OFF. Turn on the Velodyne Lidar
power 60 seconds before starting mapping/localization.
STENCIL 2 POWER/OPERATING MODE BUTTON
Press once to turn on. The blue LED ring around the button will illuminate to verify the processor
has started. The USB indicator will illuminate blue when Stencil has completely booted up.
After power to Stencil 2 is on and Lidar is on for at least 60 seconds, press the left button once to
Start Mapping/Localization. Press again to Stop when mapping/localization is complete. Wait for
the yellow USB indicator to stop blinking and turn blue. You can repeat mapping/localizing in this
fashion. Once you have finished and the USB indicator is blue, you can press the left button twice
to turn Stencil 2 off.
VELODYNE LIDAR/OPERATION BUTTON
Turn on the Lidar by depressing the button until it latches. The blue LED ring around the button
will illuminate to verify that the Lidar is on.
Turn off the Lidar by depressing the button until it unlatches. The blue LED ring around the button
will turn off.
The lidar needs to be on for at least a minute prior to initiating mapping/localization.

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USING STENCIL 2 OUT OF THE BOX
A battery is shipped with Stencil 2 for all US orders. International orders do not include the
battery. As shipped in the United States, the battery is not fully charged. You can start fully
charging the battery with the Battery AC Charger while you get familiar with Stencil 2 operations.
Stencil 2 software comes factory set to Mapping Mode without using the Feature Tracker. This
allows you to start mapping using only the rear panel power/mode buttons.
BEFORE YOU BEGIN MAPPING:
Ensure that the USB Status Indicator is plugged into one of the USB ports. The indicator will offer
confirmation that you are doing everything correctly, or let you know when something needs
your attention.
Turn on Stencil 2, and the Lidar. You’ll know they are on if the LED status ring around each push
button and the USB indicator is blue.
Note: Ensure that both Stencil 2 and the Lidar are both powered on for at least 60 seconds before you
begin mapping.
START MAPPING
To begin mapping, press the Stencil 2 power button once. Wait until the USB indicator turns
green and begins to blink (about 20 seconds) Wait for an additional 5 -10 seconds before you
begin moving.
Note: If the LED Indicator turns red longer than 10 seconds, refer to the USB Status Indicator Codes
for help.
STOP MAPPING
To stop mapping, press the left button once. The USB Status Indicator will turn blinking yellow
while the point cloud is saved. This can take from a few seconds to a few minutes depending on
the data file size.
When the USB Status Indicator turns a steady blue, saving is complete and you can begin
mapping again.

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SCAN FOLDER CONTENTS
Each scan creates a subfolder in the ~/recordings directory on the desktop. A new subfolder will
also be created with “_replay” added to the folder name when using Stencil 2’s Adaptive Data
Replay tool. If you use the upgrade script to convert old Stencil files to the new Stencil 2 format,
the subfolder will have “_upgraded” added to the folder name. These subfolders may contain the
following files where xxx is the system time when the file was created.
LIST OF MAPPING FILES
pointcloud_xxx.ply
Binary point cloud file created during mapping/localization.
trajectory_xxx.ply
Trajectory file showing either the path of the Lidar during
mapping / localization or the front lens of the Feature Tracker
during Mapping with Camera / Localization with Camera.
gps_xxx.ply
GNSS data If GNSS data was available during the scan.
sensors_xxx.bag
ROS raw data file
scan_info_xxx.txt
Summary information of the Stencil mode, start / end times,
trajectory length, number of map and trajectory points, and
information related to the GNSS data available during the scan.
scan_info_xxx.yaml
Yaml file containing information during scanning / playback used
by the Loop Closure Tool and during Localization Using GNSS
Tool
pointcloud_xxx_ds.ply
Downsized binary point cloud file created during mapping /
localization as specified in the parameter file.
configuration_xxx.yaml
Stencil 2 configuration parameters in use during the scan.
last_pose_xxx.txt
Ending pose of the mapping/localization scan.
map_files sub-folder
Map used by Stencil 2 for localization. It is only created when
Choose Map for Localization is run.
image_files sub-folder
Images saved when Record Images is turned on
video.avi
Video created when Record Images is turned on
Levelling sub-folder
Leveled and cleaned point clouds with sectioned images created
by the Floor Planner Tool.
keyposes_xxx.csv
Trajectory points recorded when the Record KeyPose icon is
clicked during mapping/localization mode. If GNSS data is
available, a separate file with GNSS data at those same points will
also be recorded. This feature could be used for importing
Ground Control Points tied to Stencil 2 Trajectory points or to log
a position for cross referencing later.

16
Copy these files from Stencil 2 using a USB3 drive with a monitor and mouse. Stencil 2 supports
exFAT drives for transferring files larger than 4.3GB. Using USB3 drives reduces the time for data
transfers. Be sure to copy data off of Stencil periodically to ensure disk space for future scans.
TYPICAL SCAN_INFO.TXT FILE WITH GNSS DATA:

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Open the point cloud, trajectory, and gps data files using CloudCompare software, either on
Stencil 2 or on your desktop/laptop computer. Use the Eye Dome Lighting (EDL) function to
provide shading so the point cloud is easier to view.
In CloudCompare, save the point cloud files in other formats, such as .las. This is helpful for
some workflows using CAD software. See the section on Command Line Tools for converting to
.las without using CloudCompare.
Out-of-box mapping is the most basic way to create a 3D scan. Next, we will explore the powerful
features and functions of Stencil 2.

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CHAPTER 2
STENCIL 2 OPERATIONS
IT’S A COMPUTER
Stencil 2 not only has full computing capabilities to map large, complex structures and areas, it
can be used to review files, change operating modes, adjust parameters, and replay raw data. It
also performs post-processing data functions such as cleaning, sharpening, loop closure, and
floor plan imagery. Like any computer, it works with external devices.
Connect a desktop monitor using either the HDMI port, miniDisplayPort, or USB-C Thunderbolt
connector depending on the specific Stencil. Use the leftmost HDMI port on Stencil 2’s with S/Ns
greater than 150 as it is a protected HDMI port.
Using a USB3 hub, connect a wired keyboard and mouse or connect a wireless keyboard and
mouse using a wireless USB receiver.
Note: Be sure to provide some strain relief on the monitor cable to prevent damaging the Stencil 2
connector for Stencil S/N’s < 150.
USING THE IPAD
When processing data in the office, Stencil 2 conveniently works with a computer monitor,
keyboard, and mouse. But this set up is not practical for in-field use so Stencil 2 comes with an
iPad for changing operating modes, and starting / stopping scans.
The iPad bundled with Stencil 2 is pre-paired using the included Wi-Fi Dongle, and is configured
to work with the RealVNC App or the Remoter App installed on the iPad. The Remoter App
updates the mouse pointer on the iPad if a mouse is plugged into Stencil, but RealVNC may be
more responsive.
To use the iPad as a monitor and controller:
Start with Stencil 2 and the Lidar turned off
Insert the Wi-Fi Dongle into a USB port.
Insert the mini DisplayPort Dummy Plug into Stencil 2 [if applicable].
Turn on Stencil 2 and the Lidar.
Turn on iPad.
Connect to the Stencil 2 Wi-Fi on the iPad.
Start RealVNC or Remoter app on the iPad.
Select Stencil within the RealVNC or Remoter app

19
You should now see the Stencil 2 Desktop on the iPad.
The grey menu bar at the top of the screen brings up iPad options in
RealVNC.
Select the i icon to open the options window.
Choose between touchscreen interface or mouse interface.
Touchscreen moves the cursor to follow your finger on the screen. Mouse lets you move the
cursor on the screen by how you move your hand on the screen, even though the two are not in
the same place.
When using mouse mode, move the cursor to the desired option and then select to select the
option.

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DESKTOP ICONS
In addition to the back-panel buttons, Stencil 2 has Desktop icons that control the modes as well
as providing a user interface to the many Stencil 2 features.
START / STOP
The Start / Stop icon is a large play icon that starts and stops mapping/localization according the
mode set and visually changes depending on whether you started mapping/localization or
stopped mapping/localization.