# A Comparative Study of Indoor Accuracies Between SLAM and Static Scanners
## 2 Materials and Methods
### Used Instruments
The scanner has 32 (lidar) channels, scanning speed of 640,000/s considering a single return (up to three returns can be registered). It can store up to 512 GB of data (approx. 4 h of scanning). At its weight of 1.57 kg, it can be carried by an individual as a handheld scanner, mounted on a backpack, a vehicle, or a robot. The distributor claims a mapping accuracy of 15 mm under general conditions, 10 mm in indoor environment, and a local accuracy standard deviation of 5 mm. Data was processed in a proprietary Emesent Aura software ver. 1.8.1. The GeoSLAM ZEB Horizon RT (Figure 3f), paired with the GeoSLAM Connect 2.3.0 processing software, has a maximum range of 100 m and a field of view of 360\({}^{\circ}\)\(\times\) 270\({}^{\circ}\). The weight of the scanner is 1.45 kg and that of the data logger including the battery is 1.4 kg. The scanner is based on the Velodyne VLP-16 sensor (Velodyne Lidar, San Jose, CA, USA), capable of scanning 300,000 points per second via 16 rangefinders (called \"channels\" in the manufacturer-provided information), the claimed relative accuracy is up to 6 mm. The GeoSLAM Accuracy Report also claims that 95% of the points in the cloud are within \(\pm\)19 mm of the correct (reference) cloud targeted by a more accurate method. The Faro Orbis (Figure 3g) scanner features a maximum range of 120 m, scanning speed of 640,000 points/s, and field of view of 290\({}^{\circ}\)\(\times\) 360\({}^{\circ}\). The scanner has 32 lidar channels, a 360\({}^{\circ}\) 8 Mpix camera (once per second), measurement accuracy (SD) of 5 mm, and a Class 1 laser. The scanner weighs 2.1 kg, with an additional data logger weight of 0.95 kg. The FARO Stream app (for iOS and Android) provides scanner control, real-time data visualization, and direct sync to cloud processing with FARO Sphere XG (Faro, Lake Mary, FL, USA). The internal storage capacity is 1 TB (up to 100 h of continuous data capture). It can also perform a so-called static scan, with 19 million points acquired over 15 s, with an Improved accuracy of 2 mm. The device is also capable of identifying reference points from the cloud and using them to adjust the scanning trajectory. Moreover, placing the scanner on a georeferenced point during a pass is automatically taken into account for improving the trajectory reconstruction. Measurements with instruments in our possession (Leica ScanStation P40, Trimble X7, Trimble S9 HP) and associated data processing were performed by the authors. The basic processing of point clouds from Leica ScanStation P40 was performed in Leica Cyclone software v. 2023.0.1; the Trimble X7 point cloud was processed using the Trimble T10 tablet with Trimble Perspective software ver 2024.00 (which can be also installed on a suitable Windows 11 computer). The GNU Gama software v. 2.33 was used for data acquired from the total station. For the remaining instruments, the measurement and primary data processing were performed by the employees of the official distributors of the respective instruments within the Czech Republic. Data processing was performed in the proprietary software solutions for each of the scanners in versions valid by February 2024.