Key Research Facilities

Laser Scanning Equipment

There are three terrestrial laser scanning equipments for scanning the indoor or outdoor environment which are BLK2GO, RTC360 and Backpack Lidar as shown in Figure 1.

	Handheld-BLK2GO	RTC360	Backpack Lidar
Accuracy	10m±1cm	10m±1.9 mm 20m±2.9cm 40m±5.3cm	100m±5cm
Pros	Convenient to use Acquire data quickly Can collect the closed indoor structure through the glass Get point cloud data is fast	High accuracy Convenient to use Easy to borrow device	Wide scanning range
Cons	The resolution is lower than RTC360	Time to get point cloud data is slow Device is heavy	Output data is slow Need to be exported with special software (only one License) Heavy

Figure 1: Three laser scanning equipment

BLK2GO RTC360 LiDAR 3D scanning system- Backpack Lidar MMS

BLK2GO

According to our project requirements, the error is 1cm, so we used handheld-BLK2GO for scanning first. The BLK2GO is a handheld imaging laser scanner that creates a 3D digital twin while you walk through a space. It is the fastest and easiest way to scan a large building, structure or environment.

Lidar & Imaging

Laser class	1(in accordance with IEC 60825-1)
Wavelength	830nm
Field of view	360°(horizontal)/270°(vertical)
Range	Min.0.5-up to 25m
Point measurement rate	420,000 pts/sec
High resolution camera	12 Mpixel, 90° × 120°, rolling shutter
Panoramic vision system	3-camera system, 4.8 Mpixel 300° x 135°, global shutter

RTC360

The Leica RTC360 3D reality capture solution empowers users to document and capture their environments in 3D, improving efficiency and productivity in the field and in the office through fast, simple-to-use, accurate, and portable hardware and software.

Operation

On scanner	Touch-screen control with finger touch, full colour WVGA graphic display 480 x800 pixels
Mobile devices	Leica Cyclone FIELD 360 app for iOS and Android tablet computers and smartphones including: Remote control of scan functions, 2D & 3D data viewing, Tagging, Automatic alignment of scans
Wireless	Integrated wireless LAN (802.11 b/g/n)
Data storage	Leica MS256, 256 GB exchangeable USB 3.0 flash drive

Scanning

Distance measurement	High-speed, high dynamic time of flight enhanced by Waveform Digitising (WFD) technology
Laser class	1 (in accordance with IEC 60825-1:2014), 1550 nm (invisible)
Field of view	360° (horizontal) / 300° (vertical)
Range	Min. 0.5 - up to 130 m
Speed	Up to 2,000,000 pts / sec
Resolution	3 user selectable settings (3/6/12 mm @ 10 m)
Accuracy (At 89% albedo)	Angular accuracy 18” Range accuracy 1.0 mm + 10 ppm 3D point accuracy 1.9 mm @ 10 m 2.9 mm @ 20 m 5.3 mm @ 40 m
Range noise(For upright and upside down setups with a +/- 15° inclination)	0.4 mm @ 10 m, 0.5 mm @ 20 m

LiDAR 3D scanning system- Backpack Lidar

Backpack Scanner with the function of collecting high-precision geographic coordinate information point cloud and panoramic image. With the help of GPS positioning information, combined with lidar and Simultaneous Localization And Mapping (SLAM) technology, the Lidar Backpack DGC50 backpack lidar scanner can obtain laser point clouds and panoramic image data with high-precision geographic coordinate information. Users can simply wear this lightweight backpack and walk around the area being mapped. The System rapidly collects data to produce 3D maps with centimeter-level precision.

Major Technical Parameters

Scanner	Velodyne VLP-16 x 2
Camera	Leica’s backpack utilizes five cameras strategically placed to provide a 360° x 200° field of view
Relative Accuracy	3 cm(Affected by acquisition environment and route)
Absolute Accuracy	5 cm (Affected by acquisition environment and route)
Weight	8.6kg
Dimensions	1135318315mm(extended); 960318315mm
Point Cloud Format	.las,.laz,.ply,.LiData

Laser Scanner

Laser Scanner	Velodyne VLP-16
Max Ranging Distance	100 m
Laser Wavelength	903 nm
Horizontal FOV	0° ~ 360°
Vertical FOV	-90° ~ 90°
LiDAR Ranging Accuracy	±3 cm
Working Temperature	-10℃~ 60℃

MMS

The MMS model is ‘Leica Pegasus TRK NEO500’ and here are some brief descriptions:

Smart 3D reality capture must be kept up to date. The new Leica Pegasus TRK Neo500 is an example of the next level of mobile mapping systems, one that addresses many of the challenges this geospatially charged future poses. High precision 3D reality capture data for road and rail corridors is essential for infrastructure and asset management and even more so for the nascent autonomy market.

Measurement rate of 500kHz, scan speed of 250Hz
Maximum range 250m (50% reflectivity), 130m (10% reflectivity)
Field of view 360°, up to 4 returns, minimum range 1.5m
24MP 360° camera, 48MP butterfly side cameras, 24MP front, and 24MP rear pavement camera
For positioning, GNSS (RTK or PPK), IMU, optional DMI, and dual (front-back) SLAM scanners
7-hr battery (TRK500 Neo), up to 3 can be used
Control unit w/LCD screen. Web UI via Wi-Fi to any tablet for operation.
Accuracy: 12mm (X, Y and Z) RTK, 11mm (X, Y and Z) post-processed. With 60 second GNSS interruption: 14mm (X, Y), 16mm (Z).

Left: MMS street point cloud; Right: street HD map