Laser Scanning Method Research Articles

Non-dispersive wavepackets generated in layered structures by a scanning laser source

In this article, we describe the use of a continuous-wave laser scanning method to generate non-dispersive surface acoustic wavepackets, which propagate along the sample surface without any waveform change. To achieve this goal, a coated linear elastic film on a non-linear substrate allows for careful balancing of dispersion and non-linearity effects. The scanning speed of the laser source and the thickness of the coated film were parametrically investigated to determine the optimal scanning speed for the generation of ultrasound for a given thickness of the coated film. In the first step, four different combinations of scanning speeds and the thickness of the coated film are presented to illustrate the generation of the narrowband ultrasound. The purpose of the scanning laser source is to effectively generate large amplitude ultrasound that takes the material into the nonlinear range. Further optimization through a careful matching combination of the scanning speed and the thickness of the coated film, whereby the dispersion effect was compensated entirely by the non-linearity effect, was used to generate non-dispersive ultrasonic wavepackets, which subsequently propagate with little distortion. The main findings of the simulations indicate that non-dispersive surface acoustic wavepackets for coated systems can be generated via the scanning laser source approach for specific values of scanning speed and thickness of the coated film.

Confocal laser scanning and 3D reconstruction methods for the subsurface damage of polished optics

The subsurface damage (SSD) of optics is one of the key factors limiting the increase of energy density of high-power solid-state lasers. Because of the characteristics of small size, low density and wide distribution, it is difficult to detect the SSD of large polished optics with high-accuracy. Confocal laser scanning and three-dimensional (3D) reconstruction methods are proposed in this paper. 3D scanning in a small area is realized by a galvo and piezo stage, and sub-aperture scanning in a large area is realized by a XY stage. Sub-aperture images are stitched together to construct a volume data field, and then a modified Marching Cubes (MC) algorithm is used for 3D reconstruction. Simulations and experimental results show that the algorithm runs faster with low memory footprint, and morphologies of SSDs are displayed intuitively and accurately. The proposed methods provide quantitative evaluations such as the positions, depths and cross-sectional areas of SSDs.

A membrane protein insertion complex

The present study examined the long-standing concept that changes in hippocampal circuitry contribute to age-related learning impairment. Individual differences in spatial learning were documented in young and aged Long–Evans rats by using a hippocampal-dependent version of the Morris water maze. Postmortem analysis used a confocal laser-scanning microscopy method to quantify changes in immunofluorescence staining for the presynaptic vesicle glycoprotein, synaptophysin (SYN), in the principal relays of hippocampal circuitry. Comparisons based on chronological age alone failed to reveal a reliable difference in the intensity of SYN staining in any region that was examined. In contrast, aged subjects with spatial learning deficits displayed significant reductions in SYN immunoreactivity in CA3 lacunosum-moleculare (LM) relative to either young controls or age-matched rats with preserved learning. SYN intensity values for the latter groups were indistinguishable. In addition, individual differences in spatial learning capacity among the aged rats correlated with levels of SYN staining selectively in three regions: outer and middle portions of the dentate gyrus molecular layer and CA3-LM. The cross-sectional area of SYN labeling, by comparison, was not reliably affected in relation cognitive status. These findings are the first to demonstrate that a circuit-specific pattern of variability in the connectional organization of the hippocampus is coupled to individual differences in the cognitive outcome of normal aging. The regional specificity of these effects suggests that a decline in the fidelity of input to the hippocampus from the entorhinal cortex may play a critical role.

Large-Area Growth and Stability of Monolayer Gallium Monochalcogenides for Optoelectronic Devices

Group III monochalcogenides such as GaSe and GaS have attracted considerable interest as two-dimensional (2D) alternatives to the traditional transition metal dichalcogenides. The production of large-area films as well as the long-term ambient stability remains a challenge for scalable integration of these materials into the next generation of 2D circuitry and optoelectronic devices. In this report, a simple atmospheric-pressure chemical vapor deposition method is proposed to synthesize continuous monolayers of GaSe and GaS. The proposed method utilizes commercially available precursors and does not requires vacuum-sealed ampules or exfoliation. The optimal parameters for continuous monolayer self-limited growth were determined by systematically changing the growth time, the gas flow rate, and the amount of precursors. So far, the study of bare monolayer GaSe by Raman spectroscopy has been difficult due to the very low Raman signal and a rapid laser-induced oxidation of the material. A laser-scanning method that minimizes the cumulative laser damage and allows a reasonable signal-to-noise ratio was utilized to study the time-dependent ambient stability of bare and encapsulated monolayer samples by Raman spectroscopy. Our results reveal that bare GaSe monolayers can stand up to 6 h in air before complete degradation, and encapsulation with transparent polymeric films can delay this process for few days. These results open the door to produce large-area films of monolayer group III monochalcogenides and to consider film encapsulation with different transparent polymers that could further extend the long-term durability of these ambient sensitive 2D materials.

3D modelling of beach topography changes caused by the tombolo phenomenon using terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV) photogrammetry on the example of the city of Sopot

In 2011, a yacht marina was built in Sopot (the largest holiday resort in Poland), which initiated the formation of a local shallowing of the bottom related to the tombolo effect. The building of the marina led to disturbances in the transmission of bottom deposits along the coast, which resulted from waves and the shift of the beach coastline by approx. 50 m towards the sea. Its effects include progressive morphological changes in the shore and the sea bottom, which will lead to the formation of a peninsula between the shore and the marina in the future. This paper presents the results of a comparative analysis of the accuracy of 3D modelling of the tombolo phenomenon in the onshore part of the beach using both point clouds obtained by terrestrial laser scanning methods and photogrammetric methods based on unmanned aerial vehicle photographs. The methods subjected to assessment include both those for land modelling and for determining the coastline course and its changes. The analysis results prove the existence of sub-metre differences in the imaged relief and the coastline course, which were demonstrated using an analysis of land cross-sections. The possibilities and limitations of both methods are demonstrated as well.

Study on Material Model and Pressure Distribution Characteristics of Off-highway Minning Dump Truck Bucket

In view of the existing problems in the calculation method of the external contour of the material accumulation of the off-highway mining dump truck bucket, the reverse engineering technology and the 3D laser scanning method are proposed to accurately obtain the 3D model of the material distribution in the truck bucket. Based on the three-dimensional solid model of the material, the pressure formulas of the front plate, the side plate and the bottom plate of the bucket are derived by the force analysis method based on the thin-layer element method. References for the structure design and performance analysis of dump truck bucket are provided.

Evaluation of 3D Laser Scanning for Estimation of Heating-Induced Volume Shrinkage and Prediction of Cooking Loss of Pork Cuboids Compared to Manual Measurements

Meat shrinks and assumes an irregular shape during heating due to the varying distribution of connective tissue and extracellular spaces. The terrestrial 3D laser scanning technology is proposed as an alternative method to manual measurements to estimate the volume of irregularly shaped meat cuboids and to predict the cooking loss based on the heating induced volume shrinkage. Cuboids from aged pork loins (longissimus lumborum, n = 12) were heated at 50, 60, 70 or 80 °C for 30 min. Two methods of 3D reconstruction and volume estimation of the pork cuboids by laser scanning were used; without a base scan (laser-B) and with inclusion of a base scan (laser+B), as well as two methods based on manual caliper measurements of all twelve edges (caliper-12) or of three edges in each direction (caliper-3). Both laser scanning methods (Laser+B and Laser-B) resulted in greater volume estimates for the raw samples than the caliper-12 and caliper-3 measurements (38.3, 39.4 compared to 33.9, 34.8 cm3, respectively). Cooking loss across the different temperatures could be best predicted by the caliper-based perimeter shrinkage (r = 0.94, P 0.05) with the cooking loss. 3D laser scanning technologies can be considered by the food industry for 3D reconstruction and volume estimation, however improvements are needed in the data processing to allow for better predictability of meat quality attributes.

Laser sintering and invalidating composite scan for improving tensile strength and accuracy of SLS parts

The laser scanning method is one of the key factors in the process of selective laser sintering. Laser sintering and invalidating composite (LSIC) scanning method, which is composed of high tensile strength sintering scanning with large-spot and high accuracy invalidating scanning with small-spot, is able to improve the tensile strength, accuracy and fabrication efficiency of SLS parts. In this paper, the principle and implementation of this method were presented, and in order to prove the effectiveness of the method, the conventional scanning method was used to carry out the sintering forming experiments of the coated ceramics, and the relationship between the energy density, the tensile strength and accuracy of the parts was explored. Then based on the conclusion of this experiment, the composite scanning method is used for comparative sintering experiments. The results show that when the sintering process is carried out using the process parameters corresponding to the high tensile strength, a substantial amount of secondary sintered bodies is generated on the surface of the part and the accuracy is destroyed. The conventional scanning method cannot achieve high accuracy forming under this process condition. However, the composite scanning method can effectively eliminate the adverse influence of secondary sintering on accuracy, and achieve high tensile strength and high accuracy parts. Moreover, the method can also improve the fabrication efficiency. Therefore, this method is of great significance to realize high quality sand mould additive manufacturing and enrich the scanning method of SLS.

A Review of RTI and an Investigation into the Applicability of Micro-RTI as a Tool for the Documentation and Conservation of Modern and Contemporary Paintings

ABSTRACT Reflectance Transformation Imaging (RTI) is a non-invasive method of examination which can be used to document and visualize the surface texture of objects, including artworks. Through imaging an object under different directions of illumination, topographical maps of a low relief surface can be produced, which when further processed can be used as an interactive visual aid. This paper summarizes the current state of research on micro-RTI, and presents an investigation into a micro-RTI system comprised of a digital microscope and miniature lighting array dome, which was originally developed to study small areas of surface texture. The article reviews the techniques required to adequately use the micro-RTI, and evaluates the system’s use as a practical tool for conserving and documenting modern and contemporary easel paintings. This was determined by evaluating its data processing, ability to accurately document test panels and case study paintings, and comparing it with alternative documentation methods of standard microscopy and laser scanning. It was found that micro-RTI is a useful tool for modern and contemporary paintings and their often complex and/or delicate surfaces, where subtle surface alterations can result in visually distracting features.

Theory and methodology on safety braking of autonomous vehicles based on the friction characteristic of road surface

<p indent=0mm>Because of the direct contact between the tire and pavement, the skid resistance of asphalt pavement is a basic factor affecting the braking safety of autonomous vehicles. The road skid resistance mainly depends on the texture characteristics of the road surface. Considering the pavement friction characteristics, building a braking model of autonomous vehicles is an effective method to improve the braking safety of autonomous vehicles. In order to develop the safety braking method for autonomous vehicles based on the road surface friction characteristic, an automatic close-range photogrammetry system (ACRP system) was proposed and built based on the circle arranged three cameras close-range photogrammetry (CRP) technology to obtain the asphalt pavement surface texture accurately in real time. Automatic image acquisition and 3D reconstruction were achieved by the ACPR system. Sand patch testing method and laser scanning method (ZGScan) were applied to collect the on-site asphalt pavement texture comparing with the results of ACRP system. It shows the texture data obtained by ACPR system have relatively high accuracy and efficiency with recognition accuracy close to 0.02 mm. Then, the peak adhesion coefficients under different road conditions were calculated by considering the skid resistance contribution of the road surface texture. Based on CarSim/Simulink joint simulation, a braking model for autonomous vehicles was established. The characteristics of the autonomous vehicles during straight normal braking, emergency braking and driving on curved sections were analyzed. Then, the safety braking distance under different conditions was put forward. The research shows that the variation trends of friction coefficient curves under different pavement conditions (dry and wet pavement) are basically the same, which both decrease significantly with the increase of relative slipping ratio. When the speed exceeds <sc>40 km/h,</sc> the curve tends to be gentle, indicating that the actual contact area of the tire-road comes to a stable status when the speed is relatively high. Based on the tire hydroplaning model built by ABAQUS, the peak adhesion coefficient curves for different pavement conditions were obtained. It can be seen that the peak adhesion coefficient of the road surface is convex parabolic distribution at different driving speeds. Moreover, the peak adhesion coefficient gradually decreases as the speed increases. During normal braking, the vehicle should keep relatively low braking deceleration considering passenger comfort. As for emergency braking, autonomous vehicle should be equipped with professional short-range radar, long-range radar and high-definition camera to detect the environment surrounding the vehicle. On rainy days, the braking distance is averagely increased by about 45% compared to sunny days. When the braking distance between vehicles is large enough, it is recommended to brake with a braking force of <sc>4−6 MPa.</sc> Autonomous vehicles should keep a certain safe distance, which requires 1.1−1.2 times of the simulated average value of safety braking distance during the driving process on dry or wet pavement. As the radius of curved sections increases, the acceleration interference values under different road conditions basically reduce. When the radius is greater than or equal to<sc>100 m,</sc> the decrease rate of the acceleration interference value is more significant. In order to improve the braking comfort of the vehicles, the radius of the curved road should be controlled above <sc>100 m.</sc> In this paper, the safety strategies for autonomous vehicles considering pavement surface texture characteristics can provide references for the theoretical design of braking system and braking safety evaluation for autonomous vehicles.

Influence of Site-Specific Conditions on Estimation of Forest above Ground Biomass from Airborne Laser Scanning

Forest aboveground biomass (AGB) is an important variable in assessing carbon stock or ecosystem functioning, as well as for forest management. Among methods of forest AGB estimation laser scanning attracts attention because it allows for detailed measurements of forest structure. Here we evaluated variables that influence forest AGB estimation from airborne laser scanning (ALS), specifically characteristics of ALS inputs and of a derived canopy height model (CHM), and role of allometric equations (local vs. global models) relating tree height, stem diameter (DBH), and crown radius. We used individual tree detection approach and analyzed forest inventory together with ALS data acquired for 11 stream catchments with dominant Norway spruce forest cover in the Czech Republic. Results showed that the ALS input point densities (4–18 pt/m2) did not influence individual tree detection rates. Spatial resolution of the input CHM rasters had a greater impact, resulting in higher detection rates for CHMs with pixel size 0.5 m than 1.0 m for all tree height categories. In total 12 scenarios with different allometric equations for estimating stem DBH from ALS-derived tree height were used in empirical models for AGB estimation. Global DBH models tend to underestimate AGB in young stands and overestimate AGB in mature stands. Using different allometric equations can yield uncertainty in AGB estimates of between 16 and 84 tons per hectare, which in relative values corresponds to between 6% and 37% of the mean AGB per catchment. Therefore, allometric equations (mainly for DBH estimation) should be applied with care and we recommend, if possible, to establish one’s own site-specific models. If that is not feasible, the global allometric models developed here, from a broad variety of spruce forest sites, can be potentially applicable for the Central European region.

Modeling of Coupling Mechanism between Ballast Bed and Track Structure of High-Speed Railway

In this paper, a discrete and continuous body coupling algorithm is used to study the dynamic contact characteristics between ballasts and between ballasts and track structures. Firstly, the three-dimensional fine modeling of ballast particles is realized based on the three-dimensional laser scanning method, and then through the discrete and continuum coupling algorithm from the micro-macro point of view, a multiscale and unified particle-track structure coupling model is established. Based on the coupling model, the macro- and microdynamic characteristics of the ballast bed and the mechanical characteristics of the track structure under the dynamic load of high-speed trains with different driving speeds are studied. It is shown that the cumulative settlement of the ballast bed is directly proportional to the contact force and rotation speed of the ballast, and the faster the driving speed is, the greater the cumulative deposition speed and cumulative settlement of the ballast are. The contact force between the ballast and sleeper mainly comes from the bottom of the sleeper, and its contact force and contact strength increase with the increase of driving speed.

Analysis and Comparison of Technologies of Survey of Buildings and Structures for the Purpose of Obtaining a 3D Model

In the framework of the preservation of historical and cultural heritage, it is important to provide for the possibility of preserving and recreating a virtual historical model of the city, first of all - architectural structures. To obtain reliable spatial data about the location and configuration of the building, tacheometric survey, laser scanning and photogrammetric methods are usually used. In this paper, an experiment was conducted to obtain a three-dimensional model of the building using all the above methods. As a result, the following conclusions were made: all technologies allow us to obtain a 3D model of the property; in time field and office work, the advantages are laser scanning technology and photogrammetric methods with UAVS; in terms of efficiency, it is possible to distinguish aerial photography from UAVS, since it is relatively inexpensive compared to laser systems; in accuracy, tacheometric survey will have an advantage, since measurements are made at a specific point, and its coordinates are calculated, but this advantage can only be for buildings that are simple in geometry, for complex architectural forms and complex technical structures, the use of an electronic tachymeter is impractical

Posibilities of Use of Remote Sensing Technologies in the Castle Island Measuring Process in Jelgava

New technologies come into area of surveying more rapidly. By them work can be done safer, faster and in more interesting way and one of the newest technologies is laser scanning, result of which is point cloud, from which diverse three-dimensional models can be created. By combining photogrammetry and laser scanning methods, it is possible to obtain many-sided digital material of high quality, which is used for purposes of designing, project supervision, thus people's work is facilitated and made easier, in particular in places, which have difficult access or access can be life-threatening. The digital material, in this case relief model, allows performing above-mentioned activities remotely. For the achievement of the aim, following tasks were set: to study the available information on historical development of photogrammetry and laser scanning and principles of functioning of them; to research, analyse and describe strategy and program of sustainable development of Jelgava City; to analyse the situation of the planned Northern Flyover; to obtain spatial data for location of the planned Northern Flyover; to perform spatial data processing.

Effect of final irrigant on depth of tubular penetration of resin-based root canal sealer and bioactive sealers using confocal laser scanning microscope

Background: Deep dentin tubular penetration of the sealer provides a three dimensional sealing of root canal space Aim: To evaluate the effect of final irrigant on depth of tubular penetration of resin based root canal sealer and bioactive sealers using Confocal Laser Scanning Microscope (CLSM) Materials and Method: Ninety- six freshly extracted human mandibular first premolar teeth were decoronated at 15 mm from the apex. Cleaning and shaping procedure was accomplished using Hyflex CM rotary files till F3. The sample were divided into three groups(n=32) according to final irrgant used : Group A (17 % EDTA), Group B (QMix 2 in 1), Group C (Distilled water). The final irrigation in each respective group was performed with EndoVac system. The samples were further subdivided into 4 subgroups (n=8) according to the type of sealer used for obturation with 6% guttapercha cones - Subgroup I (AH Plus), Subgroup II (Gutta Flow Bioseal), Subgroup III ( Endosequence BC ), Subgroup IV (EndoSeal MTA). Two mm horizontal sections were obtained at 2 mm (apical sections), 5 mm (middle sections) and 7 mm (coronal sections) from the root apex using CLSM to evaluate the maximum depth and percentage of sealer penetration into the dentinal tubules by using Kruskal-Wallis test for overall analysis and a series of Mann-Whitney U tests for pairwise comparison. Result: Endosequence BC showed maximum depth of penetration and penetrated percentage perimeter, while Gutta Flow Bioseal showed least values. Q Mix 2 in 1 showed better penetration values than EDTA and distilled water. Conclusion: Irrigants, nature of sealer and level of root canal affected sealer penetratio.

Выбор методики составления топографических планов нефтегазовых объектов в зависимости от метода съёмки

The territories of oil and gas deposits are represented with complicated and diverse industrial objects. During their operation and building of new constructions it is necessary to conduct topographic survey. Various methods are used for this purpose. The selection of these methods is determined by the degree of area build-up, its size and scale of the topographic plan being created. Aerial methods of topographic surveys are relevant when mapping large territories. Terrestrial methods are used more often when surveying oil and gas objects. Among terrestrial methods classically are accepted tacheometrical survey and GNNS measurements. Terrestrial and mobile laser scanning currently gained great popularity. Introduction of laser scanning methods allowed users to significantly speed up field works keeping high accuracy of obtained data. The advantages of laser scanning application comparing to classical methods when surveying oil and gas deposits are described. It is discussed what cases of classical method application can be more preferable. To cover all the bases the description is provided on the basis of 3 deposit parts, which are different in the degree of area build-up and have different requirements for topographic plan creation as follows: scale, need to input semantic information, a format of representing the result. Introduction of new survey methods requires developing appropriate data processing techniques. As a rule, each new survey territory has its own features which should be taken into account when developing new techniques. The techniques for creating topographic plans using terrestrial laser scanning, mobile one and GNNS measurements are described.

Validation method for thickness variation of thermoplastic microcellular foams using punch-tests

This paper is concerned with a punch-test based experimental validation method and the investigation of thickness variation in forming process of a thermoplastic material. One of the key factors that characterize the final geometry of thermoformed parts is thickness variation. The material characterization process is usually based on uniaxial measurements performed at different temperature levels being relevant for the thermoforming process. Consequently, the material model can be inaccurate in biaxial stress state, which is dominant in thermoforming process. In this contribution a punch-test based validation method is presented via the case-study of a thermoplastic microcellular polyethylene-terephthalate (MC-PET) foam material. In the proposed method the thickness variation is investigated both experimentally and numerically, by means of laser scanning method and FE simulations. Finally, the utilization of the proposed method as a validation tool for the evaluation of material models that are fitted to uniaxial test data is also demonstrated.

Monitoring infrastructure facilities of territories in agricultural sector

The paper is devoted to topical issues of monitoring infrastructure facilities. The aim of the study is to compare the already established traditional method of ground-based laser scanning and its aerial analogue based on the use of compact drones in collecting data on road structures. The question was raised about the possible ways to modernize the existing monitoring procedure for the timely detection and prevention of dangerous emergencies at engineering structures. The most effective technologies for obtaining comprehensive information on the technical condition of such structures are analyzed. It was determined that the most rational method from the point of view of information content, mobility and examination time is the method of using airborne laser scanners in conjunction with unmanned small-sized aircraft. The procedure of the entire cycle of obtaining information, including its subsequent processing, is described. The analysis of stationary and other applied methods of monitoring infrastructure facilities is made, their advantages and disadvantages are described. A question was raised about the prospect of creating software that uses artificial neural networks as a means of automating the processes of subsequent processing of primary scan data and analysis of the obtained object model. Conclusions are made about the appropriateness and prospects of using similar tools and methods for the needs of monitoring engineering infrastructure facilities, as well as the need for further development of software that will automatically analyze the accumulated data on the same infrastructure object.

3D laser scanning for monitoring the quality of surface in agricultural sector

The paper considers three technologies for obtaining data on the road surface -through video recording, thermal imaging and laser scanning for the purpose of monitoring, diagnostics and control of the road quality. An analysis of the first two methods showed their significant drawbacks, such as the inability to measure the geometric parameters of deformations (video recording) and the significant dependence of the measurement results on external conditions (thermal imaging). Laser scanning, on the contrary, has a number of advantages, including coordinate referencing, obtaining a three-dimensional model, its transformation and measurement of parameters. Laser scanning is widely used, but mainly for measuring the quantitative characteristics of objects. The paper discusses the application of the laser scanning method to determine the qualitative characteristics of the road surface - the presence or absence of defects, which include hollow spots, waves, cavities, chipping, bleeding, humps, cracks, vertical displacement of road plates, rutting, unevenness of patching, damage to the road surface, track, breach, destruction of the pavement edge, subsidence followed by a complex of repair work. For this, a ground-based laser scanning was performed, the results of which were processed using the Leica Cyclone 9.4 software. According to the scanning data, defects were detected in the form of soil subsidence, hollow spots and humps. The performed work revealed a drawback of the laser scanning method, which consists in the absence of automated detection and recognition of deformations. A number of measures have been proposed to improve this drawback, which slows down the randomness and quality of work in monitoring and diagnosing the road. Further prospects for research on this topic, in particular the multi-purpose use of scanning data, by creating a distributed ledger are also indicated.

Evaluation of Uncrewed Aircraft Systems’ Lidar Data Quality

Uncrewed aircraft systems (UASs) with integrated light detection and ranging (lidar) technology are becoming an increasingly popular and efficient remote sensing method for mapping. Due to its quick deployment and comparatively inexpensive cost, uncrewed laser scanning (ULS) can be a desirable solution to conduct topographic surveys for areas sized on the order of square kilometers compared to the more prevalent and mature method of airborne laser scanning (ALS) used to map larger areas. This paper rigorously assesses the accuracy and quality of a ULS system with comparisons to terrestrial laser scanning (TLS) data, total station (TS) measurements, and Global Navigation Satellite System (GNSS) check points. Both the TLS and TS technologies are ideal for this assessment due to their high accuracy and precision. Data for this analysis were collected over a period of two days to map a landslide complex in Mulino, Oregon. Results show that the digital elevation model (DEM) produced from the ULS had overall vertical accuracies of approximately 6 and 13 cm at 95% confidence when compared to the TS cross-sections for the road surface only and road and vegetated surfaces, respectively. When compared to the TLS data, overall biases of −2.4, 1.1, and −2.7 cm were observed in X, Y, and Z with a 3D RMS difference of 8.8 cm. Additional qualitative and quantitative assessments discussed in this paper show that ULS can provide highly accurate topographic data, which can be used for a wide variety of applications. However, further research could improve the overall accuracy and efficiency of the cloud-to-cloud swath adjustment and calibration processes for georeferencing the ULS point cloud.