GreenValley LiAir 50N User manual

LiAir 50N User Guide • GreenValley International Inc.
Page 1
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LiAir 50N
UAV LIDAR System
User Guide
COPYRIGHT © 2017-2021 GreenValley International Inc.

LiAir 50N User Guide • GreenValley International Inc.
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GreenValley International Inc. (GVI) reserves all right for final explanation, and at its
sole discretion, to change, modify, and remove portions of this document.
No Part of this document may be reproduced or transmitted in any form or by any
means, electronic, mechanical, photocopying, recording, or otherwise, without prior
written permission of GreenValley International Inc.
GreenValley International Inc.
2120 University Ave. Ste. 210
Berkeley, CA. 94706
USA
+1 510.345.2899
[e-mail]
www.greenvalleyintl.com

LiAir 50N User Guide • GreenValley International Inc.
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About This Guide
This document is a general introduction and operation guide for GVI’s LiAir 50N lightweight UAV
LIDAR mapping/survey systems.
As we continue to update and improve the product, you may find some
differences between the contents of this document and your LiAir 50N
system. We will diligently update this guide as the product changes.
Please check with GVI for the latest release of this guide and contact GVI support at
[e-mail] if you have any questions.

LiAir 50N User Guide • GreenValley International Inc.
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Content
1. Read This First ..............................................................................................................................5
2. LiAir 50N System .........................................................................................................................6
2.1 About ......................................................................................................................................................... 6
2.2 System Basics........................................................................................................................................... 6
2.3 System Principles .................................................................................................................................... 6
2.4 Technical Specification .......................................................................................................................... 7
2.5 LiAir 50N System Components............................................................................................................ 8
2.5.1 Laser Scanner........................................................................................................................................................................8
2.5.2 Position and Orientation System (POS).......................................................................................................................9
2.5.3 Control and Storage Unit .............................................................................................................................................. 10
2.5.4 Integrated Camera (Optional)...................................................................................................................................... 13
3. Equipment Setup and Operation Procedure..................................................................... 13
3.1 Assemble and install LiAir 50N Payload Mounting Kit ...............................................................13
3.2 Set up GNSS Base Station...................................................................................................................14
3.3 LiAir 50N Setup and Operation (DJI M300) ...................................................................................16
4. Data Download ............................................................................................................................ 20
4.1 Download LiAir 50N Data ...................................................................................................................20
4.2 Download Base Station Data .............................................................................................................21
4.3 Download Camera Data ......................................................................................................................21
5. Data Processing............................................................................................................................ 22
5.1 Project Folder Structure ......................................................................................................................22
5.2 Data Post-processing ..........................................................................................................................24
5.2.1 Open Project...................................................................................................................................................................... 24
5.2.2 Select and Configure Parameters ............................................................................................................................... 25
5.2.3 Georeferencing Point Cloud Data .............................................................................................................................. 31
5.2.4 Data Quality Assessment............................................................................................................................................... 34
6. Special Notes............................................................................................................................. 43

LiAir 50N User Guide • GreenValley International Inc.
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1. Read This First
Important Notices
STOP! PLEASE READ THIS SECTION CAREFULLY BEFORE USING THE
PRODUCT!
LiAir 50N systems use Class 1 (IEC60825-1:2014) eye-safe laser sensors. If you have any
concerns, please contact GVI for details.
System operator must be at least 18 years old.
Tampering with the product is strictly prohibited and will void the Product Warranty. Any
repair, modification, or upgrade must be performed by GVI technician or authorized service
provider.
Do NOT use any power supply outside the specified voltage range (12~24 V, 0.7A@24VDC).
Incorrect voltage supply may cause permanent damages to the integrated instruments and
other hazards. Damage caused by the use of an unauthorized power supply are not covered
by the Product Warranty.
STOP using the product and contact GVI support immediately, if there is any visible damage
or if persistent system warnings or alarms are observed. Failure to do so may result in
permanent damage to the LiAir 50N system.
This product is NOT water-proof. Do NOT operate in rain or snow. Water damage is NOT
covered by the Product Warranty.
This product is a high-precision mapping and surveying instrument that must be handled
with care. Damage caused by improper handling of the product are not covered by the
Product Warranty.
Properly disconnect all batteries, antennas, and cables after use.
This product should by stored and transported in the protective case provided with the LiAir
50N at the time of purchase or in a productive case authorized for use by GVI.
Clean the product thoroughly after each use. Do NOT use water.
When not in use, store LiAir 50N system and accessories in a cool and dry environment.

LiAir 50N User Guide • GreenValley International Inc.
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There may be additional notices and warning in placed throughout
part this document. Read each notice and warning carefully and please
follow the instructions.
2.LiAir 50N System
2.1 About
LiAir 50N UAV-LIDAR system is a light-weighted (1.4 kg incl. camera) and 3D surveying and mapping
instrument designed to be mounted to multi-rotor aerial platforms (DJI M300 & DJI M600). LiAir 50N
provides accuracy point cloud data for users in various industries including topographic surveying,
forestry, vegetation management, power line inspection, and many more. For additional information
on LiAir 50N, please contact GVI at [e-mail].
2.2 System Basics
The LiAir 50N system integration is comprised of multiple technologies, including:
➢Laser Scanner (LIDAR sensor)
➢GNSS (Global Navigation Satellite System)
➢IMU (Inertial Measurement Unit)
➢System Control and Storage Unit
➢Power Supply and Management Unit
The GNSS unit and IMU unit together form what is often referred to as
the LiAir 50N’s POS Module.
2.3 System Principles
➢In operation, the System Controller receives and executes operational commands that control
the collection of data by each of the LiAir 50N’s integrated sensors and measurement devices.
➢The POS Module (GNSS and IMU) determines LiAir 50N’s position and attitude at any given
point in time. This time-series position and attitude data is commonly referred to as the LiAir
50N’s trajectory or POS data.

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➢The precise 3D coordinates of each data (LiDAR) point measured by the LiAir 50N’s Laser
Scanner are registered together to a common coordinate system and georeferenced using
the POS data.
➢LiAir 50N data are saved to the System Control and Storage Unit and can be downloaded
from the device after data collection has been stopped.
2.4 Technical Specification
Table 1. LiAir 50N Ultralight Specifications
LiAir 50N SPECIFICATIONS
Key Parameters
Weight
1.4 kg (Incl. camera)
Scan Range
100 m @ 20% reflectivity
System Accuracy
± 5 cm
Voltage
12~24 V, 0.70 A @ 24 VDC
Effective Scan Rate
300,000 points/s (first or strongest return)
Working Temperature
0℃~40℃
Storage Temperature
-10℃~60℃
Dimensions
198*100*163mm
LIDAR Unit
Wavelength
903 nm
Field of View
360°(horizontal) ×30° (vertical)
Eye-safe Laser Sensors
Class 1 (IEC60825-1:2014) (Safe for Eye)
Range Accuracy
3 cm
# of Lines
16
Horizontal Resolution
Vertical Resolution
0.08°- 0.33° (horizontal）
1.33° (vertical)
Scan Rate
300,000 points/s (first or strongest return)
600,000 points/s (dual return)

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2.5 LiAir 50N System Components
2.5.1 Laser Scanner
The Velodyne’s Puck LiDAR sensor is the LIDAR sensor integrated into the LiAir 50N Ultralight system.
The LiDAR sensor transmits an ultrashort pulse of NIR energy that strikes objects within the Laser
Scanner’s field of view and reflects back to the Laser Scanners receiver as a light echo. By measuring
the amount of time that has elapsed between signal transmission and signal reception (detection),
the distance from the laser scanner to the reflecting object can be determined.
As shown below, the Velodyne’s Puck has a FOV of 360° horizontally and 30° vertically. Note that the
effective detecting distance of the Velodyne’s Puck varies based on where the object is within the
FOV. The closer to the edge of the FOV, the shorter the effective detecting distance is. The closer to
the center of the FOV, the further the effective detecting distance.
Integrated
Navigation System
GNSS
GPS, GLONASS, GALILEO & BeiDou
POS System
Performance (after
post-processing)
Attitude: 0.008°
Azimuth: 0.038°
Drone Suppliers
DJI
DJI M300 RTK & DJI Matrice 600 Pro
Georeferencing
Software
Acquisition/PP POS
Software
LiGeoreference, (a self-developed LIDAR
point cloud georeferencing software)

LiAir 50N User Guide • GreenValley International Inc.
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Figure 1. LiAir 50N Product
Notice: Avoid direct exposure of the laser scanner to any laser pulse
from other laser transmitters. The laser scanner cannot be directed by
any strong laser (including the laser from laser transmitter of other
laser scanner). The strong laser can do permanently damage to the
receiver of the laser scanner.
2.5.2 Position and Orientation System (POS)
The airborne Position Orientation System (POS) is an inertial measurement unit (IMU) and Global
Navigation Satellite System (GNSS). POS systems are used to accurately determine system velocity,
position, and attitude values at specific moments in time.
a) Global Navigation Satellite System (GNSS)
Global navigation satellite system, or (GNSS) on LiAir 50N supports, mainly includes GPS, GPS (the
U.S.), Galileo satellite navigation system, (Europe), BeiDou Navigation Satellite System (China), and
GLONASS (Russia). The GNSS of LiAir 50N includes the aviation GNSS antenna and the base station
antenna.
b) Inertial Measurement Unit (IMU)
Inertia measurement unit, or IMU, consists of a high-accuracy three-axis gyroscope and a high-
accuracy three-axis accelerometer. It is the benchmark center of the LiDAR system. Its role is to get
the position and orientation information without external reference data.

LiAir 50N User Guide • GreenValley International Inc.
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The LiAir 50N integrates a 3-axis MEMS (Micro-Electro-Mechanical System) gyroscope, 3-axis MEMS
accelerometer and dual GNSS/BD receivers into one system, the POS system. Together the POS
system components gather multi-reference parameters that provide accurate, effective and reliable
(BLANK) by optimization algorithm of integrated navigation system.
Table 2. LiAir 50N Ultralight POS System Performance (after post-processing)
POS System Performance
System Accuracy
Attitude: 0.008°
Azimuth: 0.038°
2.5.3 Control and Storage Unit
a) Function:
➢Receiving the commands from the computer and executes the commands.
➢Controlling and coordinating each sensor to work properly.
➢Storing the data. The SD card inside is used to store the data of IMU, camera, and device log.
b) LiAir 50N Ultralight power and data ports, ON/OFF button, GNSS antenna ports, as well as
indicator LEDs are located on the front and sides of the LiAir 50N’s main body:
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