Terrain Mapping Research Articles

Graph-Clustering Method for Construction of the Optimal Movement Trajectory under the Terrain Patrolling

The method of the optimal movement trajectory construction in the terrain patrolling tasks is proposed. The method is based on the search of the Hamiltonian circuit on the graph of the terrain map and allows automatic construction of the optimal closed path for arbitrary terrain map. The distinguishing feature of the method is the use of the modified algorithm for the Hamiltonian circuit search. The algorithm can be scaled for the maps corresponding to the graphs with a large (more than 100) number of the vertices, for which the standard brute-force algorithm of the Hamiltonian circuit search requires significantly higher execution time than the proposed algorithm. It is demonstrated that the utilized algorithm possesses 17 times less constant of the time complexity growth than the standard brute-force algorithm. It allows more than one order of magnitude (from 30 to 500 vertices, i.e., approximately to the 17 times) increase of the graph vertices that is used for the Hamiltonian circuit search in the real time (0.1–100 s) regime.

Wheel-SLAM: Simultaneous Localization and Terrain Mapping Using One Wheel-Mounted IMU

A reliable pose estimator robust to environmental disturbances is desirable for mobile robots. To this end, inertial measurement units (IMUs) play an important role because they can perceive the full motion state of the vehicle independently. However, it suffers from accumulative error due to inherent noise and bias instability, especially for low-cost sensors. In our previous studies on Wheel-INS [1], [2], we proposed to limit the error drift of the pure inertial navigation system (INS) by mounting an IMU to the wheel of the robot to take advantage of rotation modulation. However, Wheel-INS still drifted over a long period of time due to the lack of external correction signals. In this letter, we propose to exploit the environmental perception ability of Wheel-INS to achieve simultaneous localization and mapping (SLAM) with only one IMU. To be specific, we use the road bank angles (mirrored by the robot roll angles estimated by Wheel-INS) as terrain features to enable the loop closure with a Rao-Blackwellized particle filter. The road bank angle is sampled and stored according to the robot position in the grid maps maintained by the particles. The weights of the particles are updated according to the difference between the currently estimated roll sequence and the terrain map. Field experiments suggest the feasibility of the idea to perform SLAM in Wheel-INS using the robot roll angle estimates. In addition, the positioning accuracy is improved significantly (more than 30%) over Wheel-INS.

Terrain mapping and analysis for land management: the case of Megech-Dirma watershed, sub-basin of the Blue Nile basin, Northwest Ethiopia

Terrain mapping and analysis for land management: the case of Megech-Dirma watershed, sub-basin of the Blue Nile basin, Northwest Ethiopia

Miniaturized superconducting single-photon detection system for airborne platform

<sec>Facing the demand for applications such as wide-area terrain mapping and space-based atmospheric measurements, there is an urgent need to develop miniaturized single-photon detection systems with low power consumption that can be adapted to airborne platforms. Superconducting nanowire single-photon detectors (SNSPDs) have been applied to quantum information, bioimaging, deep space communication and long-range lidar with the advantages of high quantum efficiency, low dark count rate and fast detection rate. However, traditional SNSPD usually operates at 2.1 K or even lower, and the required cryogenic systems are large in size and weight, which are not easy to apply to airborne platforms. Up to now, there has been no report on SNSPD applied to airborne platforms. How to apply SNSPD to airborne platforms is an urgent problem to be solved.</sec><sec>In this work, we design and make an SNSPD with an operating temperature of 4.2 K. The superconducting detector chip is a four-channel photon-number-resolving device with a photosensitive area of 60 μm × 60 μm, which is coupled to a 200-μm-diameter fiber by a beam compression system with a quantum efficiency of 50% at 1064 nm and a temperature of 4.2 K. Finally, the time characteristics of a single channel are tested in response to different photon numbers. The timing jitter of four-photon response is smallest, and the half-height width is 110 ps. This work not only supports airborne applications, but also has positive implications for promoting the development of general-purpose miniaturized SNSPD systems and their applications.</sec>

Monocular vision-based multiinformation map construction framework for field terrain

Three-dimensional (3D) spatial data, terrain type, and physical properties of field terrain are very important information for mobile robots in trajectory planning, force adjustment, motion control, dynamic parameter optimization, and so on. Obtaining the information in advance through vision can provide a prior perception to help make reasonable decisions and improve security and adaptability. We present the first monocular-vision-based multiinformation map construction framework for field terrain. The current state-of-the-art physical properties inference algorithm is promoted in illumination robustness, time consumption, and terrain richness. Our improvement makes it possible to apply physical properties inference to the real-time mapping of field terrain. An improved monocular vision and inertia fused localization scheme is used to introduce the gravity direction. Depending on the obtained terrain segmentation and camera pose, an unsupervised monocular scale-consistent terrain dense depth estimation method with comprehensive geometric constraints is designed. Finally, the components are systematically combined to form a complete framework, and the ambiguity of inference results between multiview frames is addressed. Comprehensive experiments are conducted to verify the effectiveness of each component and the performance of the overall framework. Our multiinformation map construction framework can output a gravity-aligned 3D RGB map, terrain map, friction property map, and stiffness property map at once with high accuracy.

Performance of UAV Image for Flood Mapping with 2 Dimensional Model in Kaliputih River, Panti District

In January 2006, the flash flood in Panti Sub-district was a national disaster, causing damage to building infrastructure and fatalities. From this incident, it is necessary to have flood mitigation by providing a map of the distribution of flood inundation using a 2D hydraulic model to provide information regarding the extent of flood inundation in the study area. Due to the limited DEM data for 2D modeling, it is necessary to use UAV images to provide a DSM with good and higher resolution. This study aims to assess the performance of 2D flood modeling results using HEC-RAS equipped with RAS Mapper through UAV processing as input. There are 21 GCP in the study area as an increase in accuracy, the RMSE value in the horizontal direction is 0.3853m, and the vertical direction is 0.1836m. From the CE90 accuracy test results for a horizontal accuracy of 0.58m and LE90 for a vertical accuracy of 0.30m, it can be concluded that the map accuracy test meets the 1:2500 scale. Terrain maps are input to HEC-RAS; selected meshes are 5x5m and 2x2m. The modeling results can show the inundation depth in each GCP from the min-max depth. The model calibration shows an RMSE value of 0.183, while the flood depth validation shows an RMSE value of 0.13. In other words, modeling can represent the distribution of flood inundation in the study area and provide benefits for the community to be more alert in the event of a flood in the coming year.
 Keywords : UAV; GCP; DSM; HEC-RA; Flood mapping
 
 Copyright (c) 2022 Geosfera Indonesia and Department of Geography Education, University of Jember
 This work is licensed under a Creative Commons Attribution-Share A like 4.0 International License

Construction of a Measurement System with GPS RTK for Operational Control of Street Lighting

Street lighting should realise normative illuminance levels throughout the roadway. The determination of the illuminance level of a road requires the use of a measurement technique based on classic point measurements at a specific grid of measurement points. Classical stationary measurements using the method indicated in the prescriptive requirements are time-consuming and labor-intensive. The authors of the article have presented a concept of a measurement system that could be used to partially automate road lighting measurements and increase their universality. The proposed measurement system uses the simultaneous measurement of illuminance values from lux meters located on the roof of the vehicle. The measurement is carried out while the vehicle is driving on a lit road, and the illuminance values are localized using a global GPS satellite location system equipped with RTK corrections. The use of GPS RTK localization data corrections allowed the measurement results to be unambiguously assigned to post-measurement fields. On the basis of the collected measurement data, with the use of terrain maps, it is possible to determine in detail the illuminance parameters on the surveyed road sections. The paper presents the construction of a measurement system for the mobile measurement of street lighting intensity using a GPS RTK receiver, along with verification of its correct operation. The correctness of the system’s operation was confirmed on the basis of the Measurement System Analysis (MSA) method. The calculations performed confirmed an R&R result of 11.14%. The proposed solution allows data on the lighting parameters of the surveyed road section to be obtained in a quick and repeatable manner. As a result, it is possible to make a quick assessment of the street lighting condition of the entire road section. The proposed system has been verified under field conditions and the repeatability of the results obtained has been confirmed.

Application of Unmanned Aerial Vehicle (UAV) in Terrain Mapping: Systematic Literature Review

Unmanned Aerial Vehicle (UAV) is an advanced technology that can be control remotely. It hovers up in the air and travel with different height and distance depending on the capability of the UAV. Originally, this technology was invented for military practice. Now, the innovation of UAV is growing and have contribute to various field including terrain mapping in surveying work. Carrying out mapping task in terrain such as mountain, valley, plateau, or rainforest can be a difficult task in-terms of time, practicality and cost. Another challenge is when the survey area is permanently clouded over and the limited availability of aircraft platforms and the orbit features of satellites causing difficulties to obtain high quality photos. Therefore, there are much research that used UAV technology to do mapping work and obtain Digital Terrain Model (DTM), Digital Surface Model (DSM) and Digital Elevation Model for various purposes. In this study, systematic literature review using thematic analysis methodology was used to review, evaluate and combine relevant literature review. The aim of this study is to categorise the application for terrain mapping using UAV and also to identify the system and result improvement of UAV during the usage in terrain mapping. From the thematic analysis, two themes which are understanding the earth structure with the subtheme of geotechnical study, geomorphological study and flood study and UAV system improvement with the subtheme of accuracy assessment, accuracy enhancement and resolution were formed.

Towards energy efficient autonomous exploration of Mars lava tube with a Martian coaxial quadrotor

Mapping and exploration of a Martian terrain with an aerial vehicle has become an emerging research direction, since the successful flight demonstration of the Mars helicopter Ingenuity. Although the autonomy and navigation capability of the state of the art Mars helicopter has proven to be efficient in an open environment, the next area of interest for exploration on Mars are caves or ancient lava tube like environments, especially towards the never-ending search of life on other planets. This article presents an autonomous exploration mission based on a modified frontier approach along with a risk aware planning and integrated collision avoidance scheme with a special focus on energy aspects of a custom designed Mars Coaxial Quadrotor (MCQ) in a Martian simulated lava tube. One of the biggest novelties of the article stems from addressing the exploration capability, while rapidly exploring in local areas and intelligently global re-positioning of the MCQ when reaching dead ends in order to efficiently use the battery based consumed energy, while increasing the volume of the exploration. The proposed novel algorithm for the Martian exploration is able to select the next way point of interest, such that the MCQ keeps its heading towards the local exploration direction where it will find maximum information about the surroundings. The proposed three layer cost based global re-position point selection assists in rapidly redirecting the MCQ to previously partially seen areas that could lead to more unexplored part of the lava tube. The Martian fully simulated mission presented in this article takes into consideration the fidelity of physics of Mars condition in terms of thin atmosphere, low surface pressure and low gravity of the planet, while proves the efficiency of the proposed scheme in exploring an area that is particularly challenging due to the subterranean-like environment. The proposed exploration-planning framework is also validated in simulation by comparing it against the graph based exploration planner. Intensive simulations with true Mars conditions are carried out in order to validate and benchmark our approach in a utmost realistic Mars lava tube exploration scenario using a Mars Coaxial Quadrotor.

Обнаружение и отслеживание объектов на основе карты внимания для БПЛА

Object detection and tracking is one of the most important areas of computer vision, as well as applications in unmanned aerial vehicles (UAVs). However, due to the ultra-maneuverability of the UAV mobile platform, the image in the air is usually blurry and has a low signal-to-noise ratio, which is associated with the working environment. To solve the problem of detecting ground objects on the UAV platform, traditional methods of pattern recognition and classification are often ineffective. The visual attention model is a kind of bionic vision model with good stability. In the article for the detection of ground objects using UAVs, a method based on the visual saliency model is proposed, applied to a complex terrain background for object detection. To quickly isolate terrestrial features in aerial photographs, the extracted gradient function is applied to detect an area of visual significance, and then the target image is extracted using a segmentation algorithm. The subject of the study is the method and algorithm for detecting ground objects on the map of the underlying surface using the visual saliency model and object segmentation. The object of the study is a set of video sequences of terrain maps with different terrain. The novelty of the work is an algorithm that allows detecting ground targets based on an attention map using an object segmentation algorithm. A new method for segmenting objects in a video sequence is proposed. Experimental studies were carried out on the basis of video sequences of the map of the underlying surface with different backgrounds and an analysis of the results obtained was carried out. The results obtained make it possible to identify objects in the region of interest. As a result of solving the formulated tasks, the following conclusions can be drawn: An algorithm for detecting ground objects based on an saliency map has been developed. An algorithm for segmentation of ground objects based on a gradient map has been developed. An analysis of the results of the study showed that the proposed algorithm makes it possible to detect and highlight ground objects on a map of terrain with different terrain.

АНАЛИЗ ПОДСТИЛАЮЩЕЙ ПОВЕРХНОСТИ ПРИ ФОРМИРОВАНИИ ИЗОБРАЖЕНИЯ В РЕЖИМЕ ДОПЛЕРОВСКОГО ОБУЖЕНИЯ ЛУЧА

Radar based on real beam scanning is widely used in both civil and military spheres. However,it is difficult to realize high azimuth resolution of a stationary platform or a platform with nonuniformmotion using conventional signal processing algorithms. Doppler beam sharpening (DBS)technology is a combination of high resolution and real-time performance compared to SyntheticAperture Radar (SAR) technology, which uses the Doppler shift between echoes from objects on theunderlying surface along the azimuth direction, caused by the movement of the radar platform. Unfortunately,the traditional DBS imaging algorithm, which constructs a Doppler filter using an FFT,has a low azimuth resolution and a high level of side lobes, which limits further improvement in azimuthresolution. In the article, the algorithm for constructing a map of the underlying surface in thedirection of movement of the radar carrier based on the DBS was studied and the map image wasanalyzed using the Fourier transform. A three-dimensional view of the map of the underlying surfaceis shown with the distribution of values in the images. The subject of the study is the method and algorithmfor constructing a map of the underlying surface in the Doppler beam sharpening mode andidentifying chain structures based on the analysis of the Fourier transform. The object of the study is a set of test images of the terrain map. The result of the study is the development of an algorithm forconstructing a map in order to identify chain structures on the underlying surface. The novelty of thework is an algorithm that allows you to build a map of the underlying surface based on the DBS,taking into account the blind zone in the direction of movement of the radar carrier. The results obtainedalso make it possible to reveal chain structures in the region of interest. The possibility ofestimating the periodicity of image elements using the Fourier transform has been tested. As a resultof solving the tasks set, the following conclusions can be drawn: – an algorithm has been developedfor constructing a map of the underlying surface based on DBS with image correction in the directionof movement of the radar carrier. – analysis of the results of the study showed that the proposed algorithmallows you to identify chain structures on the map.

GIS Based Assessment and Analysis of Terrain Variables in Kampung Baru, Jeli, Kelantan

Kampung Baru is one part of Jeli district that has abundant natural resources and contains several geological features of interest.The landscape of this area is divided into three parts which are mountainous, hilly, and plain areas. This research aims to perform terrain analysis and determine the suitability zone for the construction area. To achieve the objective, the mapping aspect is mainly based on field observations such as geomorphological features, elevation, drainage patterns, etc. Besides, elevation data extracted from Digital Elevation Model (DEM) was employed to characterize the physical features of the landscape for terrain mapping and analysis. All this field-related data was then processed in ArcGIS software to generate thematic maps. The terrain classification was carried out based on five terrain variables: slope gradient, terrain code, activity code, erosion & instability. Then, the suitability of the site for development and construction is created using the terrain attributes. There were five types of classes created in the study area: class I (37.9 %), class II (23.3 %), class III (1.7 %), class IV (29.3 %), and class IV cut slope (7.6 %). The study area was dominated by class I, which means it has few geotechnical constraints and is highly suitable for development. Some cutting and filling of slopes are not expected to be difficult due to their low elevation. From the slope terrain analysis, only 4.89 % of the site is covered by a very steep slope (>60°). The site is mainly high slopes (35° - 60°), equal to 32.20% of the total area, with most of it contributed by the cut slopes. Gently sloping (5° - 15°) to moderate slope rate (15° - 25°) covers about 19.93% and 14.19% of the area respectively. The percentage of flat to gently sloping (0° - 15°) area is shown as 15.34 % of the project site. In conclusion, the parameters including the map prepared using the Weighted Overlay Method (WOM) can be beneficial to engineering geology for the planning of site investigations, preliminary design of foundation systems, and the project layout of the research area.

Martian wind and surface conditions during the night-time descent and landing of Pathfinder

Pathfinder parachuted through the Martian nocturnal boundary layer during the northern hemisphere summer. Encased in airbags the lander bounced across the surface in darkness coming to a stop surrounded by a rugged terrain. Studying the motion of Pathfinder during its descent and landing offers a unique opportunity to study the Martian winds at night in the stable boundary layer. We simulate the atmospheric descent of Pathfinder using a trajectory model together with winds imported from a global climate model. The bouncing trajectory of the airbags was investigated using atmospheric pressure observations made during the landing and a Digital Terrain Map (DTM).Reconstruction of the parachute and airbag trajectories together with accelerometer data indicates that there was possibly strong wind shear in the nocturnal boundary layer prior to the firing of the braking rockets. This is unexpected from atmospheric models. Atmospheric pressure data and the DTM indicate the first airbag impact was on the side of a low hill north of the deployed lander. From this point our airbag model indicates the airbags would have bounced downhill towards the south by about one hundred metres and descended several metres in elevation before arriving on level ground where they would have slowed to a stop.We use modern observations and analytical tools to reconstruct the descent and landing of Pathfinder and provide information on the atmospheric and surface conditions during the night-time landing. In addition we provide clues to the behaviour of the nocturnal boundary layer on Mars.

Online Aerial 2.5D Terrain Mapping and Active Aerial Vehicle Exploration for Ground Robot Navigation

Online Aerial 2.5D Terrain Mapping and Active Aerial Vehicle Exploration for Ground Robot Navigation

Bounds Calculation Method of Electromagnetic Availability Zone of Radio Emission Source

The article deals with the problem of determining the electromagnetic availability zone of the radio transmitter of the radio communication channel in the UHF/VHF range on the terrain map of the area. This problem was solved using well-known mathematical models of radio signal propagation, depending on the characteristics of the specific area. Based on the wave algorithm, a bounds calculation method of electromagnetic availability zone is proposed, using a digitized radiation pattern of radio means. The conducted calculations show the effectiveness of the method in the tasks of assessing the performance of a mobile radio communication channel and its security at local combat operations in the conditions of operation of an enemy radio reconnaissance receiver or a radio interference system.

Improved Combined Metric for Automatic Quality Assessment of Stitched Images

An automatic quality assessment of stitched images is an essential task in image analysis and is particularly useful not only in the creation of general-purpose panoramic images but also in terrain exploration and mapping made by mobile robots and drones. In Visual Simultaneous Localization and Mapping (VSLAM) solutions, the environment maps acquired by cameras mounted on the mobile robots may be captured in dynamically changing lighting conditions and subject to some other distortions influencing the final quality of the panoramic images representing the robot’s surroundings. Such images may also be used for motion planning and visual navigation for other robots, e.g., in follow-the-leader scenarios. Another relevant application area of panoramic imaging is Virtual Reality (VR), particularly head-mounted displays, where perceived image quality is even more important. Hence, automatic quality evaluations of stitched images should be made using algorithms that are both sensitive to various types of distortions and strongly consistent with subjective quality impression. The approach presented in this paper extends the state-of-the-art metric known as the Stitched Image Quality Evaluator (SIQE) by embedding it with some additional features using the proposed new combination scheme. The developed combined metric based on a nonlinear combination of the SIQE and additional features led to a substantially higher correlation with the subjective quality scores.

Algorithms for Calculating the Trajectory of Unmanned Aerial Vehicles for Solving Agricultural Problems

The relevance of using unmanned aerial vehicles (UAV) is substantiated in comparison with other methods of aerospace survey. The paper provides examples of tasks requiring the use of UAVs for aerial photography from different heights. It is shown that the introduction of agricultural robots, including UAVs, increases the speed of fi eld work, allows obtaining unique data necessary for the assessment of agricultural territories, crops processing and plant growth stimulation. It is noted that the problem of constructing the movement trajectories of a multirotor UAV for performing agricultural tasks within a minimum time limit remains unresolved. (Research purpose) To reduce the length of the trajectory covering a given area and reduce the flight time of a multirotor UAV, taking into account the analysis of possible obstacles and land plots that are beyond the task scope. (Materials and methods) Geometric methods have been used to calculate the UAV flight trajectory covering a given section, the trajectory of movement in an environment with obstacles to the designated point. Photogrammetry methods have been used for processing aerial photography images when forming an orthophotoplane and a terrain map. (Results and discussion) The trajectory calculated by the developed algorithm proves to meet all the requirements: it is continuous, has a minimum number of turns, it is smoothed, and feasible for a multirotor UAV. (Conclusions) It was determined that according to the proposed algorithm it takes less than 0.05 seconds to calculate the trajectory covering a rectangular section with the sides of 200 by 30 meters. It was found that the trajectory in the fi rst 10,200-square-meter section decreased by 9 percent, and in the second 950,000-square-meter section it reduced by 6 percent, compared with the length of the trajectory built using standard algorithms. The flight time reduced by 32 and 10 percent, respectively. The paper presents the key advantages of using UAV for video shooting such as: guaranteed high resolution of photographic materials and the ability to shoot at a given time, allowing for the crop condition assessment.

Automatic speech recognition for unmanned aerial vehicles

Unmanned aerial vehicles (UAVs), also known as unmanned aerial systems (UASs), are quickly becoming a ubiquitous technology, poised to enter some key large-scale markets in the very near future. Fleets of such vehicles will be required in these large-scale deployments for commercial, industrial, and emergency response, along with the ability to efficiently control these fleets. Voice control and communication between human operators and these fleets will become imperative. This paper explores the framework for building an automatic speech recognition (ASR) use to the control of unmanned aerial vehicles (UAVs). The ARS system will be used by Aeronyde Corporation to fully-autonomous fleets with minimal human intervention. Aeronyde Corporation is working to shift and advance the current industry thinking of unmanned platforms from Remotely Piloted Aircraft (RPA) to fully-autonomous fleets with minimal human intervention. The Aeronyde Avionics package enables a single operator to control and monitor missions of many drones in real time anywhere in the world. The “1 Pilot – Many Drones” approach to aerial data collection is revolutionary for Big Data aggregation and analytics of the 4th Industrial Revolution. Multi-UAV autonomous aerial systems will transform data acquisition for many commercial applications, including: agriculture and forestry, railroad inspections, pipeline inspections, powerline inspections, windmill inspections, terrain mapping, search and rescue, firefighting and police work, and border patrol.

A simplified GIS and google-earth-based approach for lineaments and terrain attributes mapping in a basement complex terrain

In this study, we use an integrated geologic mapping technique for remote mapping of lineaments and geologic terrain. Our workflow is based on geographic information system tools and consists of stream network delineation, lineaments mapping, terrain roughness index calculation, and interpretation of structural fabrics from google earth aerial photographs. The case study area, the Idanre Hills in southwestern Nigeria, has a protracted history and is characterized by steep-sided outcrops of a granitic batholith and migmatite-gneiss. Lineaments are widespread and dense around the batholith, occurring in areas of high elevation, and slope gradient. Terrain roughness indices are high at the outcrops and lineament sites. Streams in the area exhibit variable flow and partly align with the lineaments. The high roughness indices observed have tectonic connotations and are related to the occurrence of lineaments, strain domains, and high degree of rock weathering. Importantly, our method is effective in remote mapping of lineaments and terrain attributes within the study area and has wider applications in other basement complex terrains.

A new comprehensive performance optimization approach for Earth-contact mechanism based on terrain-adaptability task

AbstractEarth-contact mechanism (ECM), a type of mechanism to keep the system in contact with the earth and to move with the terrain changes. This paper uses the virtual equivalent parallel mechanism (VEPM) to convert the terrain data into the kinematical variables of the moving platform in the VEPM, and further analyzes the performance of the VEPM at each terrain point. Then, the comprehensive performance of the VEPM is chosen as the optimization goal, and a task-oriented dimensional optimization approach combined with the particle swarm algorithm and the neural network algorithm is proposed. This paper conducted a comparative experiment to verify the superiority of the new approach in optimizing the ECM’s comprehensive performance, whose performance analysis also can be applied into the layout design of the ECM. This paper proposed an analysis method to construct the ECM’s performance map based on the digital terrain map, which helps the control system and operator to make the optimal control decision.