Geodetic Coordinate System Research Articles

Manipulation Planning for Object Re-Orientation Based on Semantic Segmentation Keypoint Detection.

In this paper, a manipulation planning method for object re-orientation based on semantic segmentation keypoint detection is proposed for robot manipulator which is able to detect and re-orientate the randomly placed objects to a specified position and pose. There are two main parts: (1) 3D keypoint detection system; and (2) manipulation planning system for object re-orientation. In the 3D keypoint detection system, an RGB-D camera is used to obtain the information of the environment and can generate 3D keypoints of the target object as inputs to represent its corresponding position and pose. This process simplifies the 3D model representation so that the manipulation planning for object re-orientation can be executed in a category-level manner by adding various training data of the object in the training phase. In addition, 3D suction points in both the object’s current and expected poses are also generated as the inputs of the next operation stage. During the next stage, Mask Region-Convolutional Neural Network (Mask R-CNN) algorithm is used for preliminary object detection and object image. The highest confidence index image is selected as the input of the semantic segmentation system in order to classify each pixel in the picture for the corresponding pack unit of the object. In addition, after using a convolutional neural network for semantic segmentation, the Conditional Random Fields (CRFs) method is used to perform several iterations to obtain a more accurate result of object recognition. When the target object is segmented into the pack units of image process, the center position of each pack unit can be obtained. Then, a normal vector of each pack unit’s center points is generated by the depth image information and pose of the object, which can be obtained by connecting the center points of each pack unit. In the manipulation planning system for object re-orientation, the pose of the object and the normal vector of each pack unit are first converted into the working coordinate system of the robot manipulator. Then, according to the current and expected pose of the object, the spherical linear interpolation (Slerp) algorithm is used to generate a series of movements in the workspace for object re-orientation on the robot manipulator. In addition, the pose of the object is adjusted on the z-axis of the object’s geodetic coordinate system based on the image features on the surface of the object, so that the pose of the placed object can approach the desired pose. Finally, a robot manipulator and a vacuum suction cup made by the laboratory are used to verify that the proposed system can indeed complete the planned task of object re-orientation.

The First Realization of BeiDou Coordinate System and Its Assessment

The BeiDou Navigation Satellite System (BDS) has used the BeiDou Coordinate System (BDCS) as its geodetic reference system since December 2017. After a brief description of the background, definitions of the origin, scale, and orientation of BDCS are given, which are consistent with China’s Geodetic Coordinate System 2000 (CGCS2000). Then the first realization of the BDCS aligning with the International Terrestrial Reference Frame 2014 (ITRF2014) is addressed. Coordinates at epoch 2018.0 and velocities at eight BDS monitoring stations were obtained achieved by processing four-phase GPS data for a global navigation satellite system (GNSS) network, including the monitoring stations, and by the frame alignment and linear regression fitting of station coordinate series. Assessment of the precision of the coordinates and Helmert parameters with respect to ITRF2014 reveals that the differences between the first frame of BDCS and ITRF2014 are less than 1 cm, which is compatible with WGS84 (G1762), PZ-90.11, and the latest Galileo terrestrial reference frame.

A New Combined Adjustment Model for Geolocation Accuracy Improvement of Multiple Sources Optical and SAR Imagery

Numerous earth observation data obtained from different platforms have been widely used in various fields, and geometric calibration is a fundamental step for these applications. Traditional calibration methods are developed based on the rational function model (RFM), which is produced by image vendors as a substitution of the rigorous sensor model (RSM). Generally, the fitting accuracy of the RFM is much higher than 1 pixel, whereas the result decreases to several pixels in mountainous areas, especially for Synthetic Aperture Radar (SAR) imagery. Therefore, this paper proposes a new combined adjustment for geolocation accuracy improvement of multiple sources satellite SAR and optical imagery. Tie points are extracted based on a robust image matching algorithm, and relationships between the parameters of the range-doppler (RD) model and the RFM are developed by transformed into the same Geodetic Coordinate systems. At the same time, a heterogeneous weight strategy is designed for better convergence. Experimental results indicate that our proposed model can achieve much higher geolocation accuracy with approximately 2.60 pixels in the X direction and 3.50 pixels in the Y direction. Compared with traditional methods developed based on RFM, our proposed model provides a new way for synergistic use of multiple sources remote sensing data.

Update China geodetic coordinate frame considering plate motion

China Geodetic Coordinate System 2000 (CGCS2000), as the formal national coordinate reference frame, has been used for 20 years. The coordinates of all Global Navigation Satellite System (GNSS) stations in China need referring to this system. To this end, the first step is to align the coordinates of all stations, usually included in a regional GNSS network, with a given International Terrestrial Reference Frame (ITRF), then these coordinates are corrected to the CGCS2000 in consideration of plate movement. For a better alignment result, regional control stations are needed and their coordinates were estimated from the combination of constraint-free normal equation systems provided by several International GNSS Service (IGS) analysis centers. The effect in using these refined coordinates, which determine a regional coordinate datum, on the alignment result should be evaluated by the coordinate corrections of the regional control stations to the regional coordinate datum, i.e. smaller corrections mean better alignments of the two associated frames. The test results show that the refined coordinates are more accurate than the ones calculated from the station's velocity, and are well aligned with the ITRF2005. Moreover, for obtaining the coordinates of GNSS stations in an updated CGCS2000 frame, a gridded linear velocity field based on the estimated velocities at 1025 CGCS2000 stations was generated for mainland China using the optimal interpolation method, the inverse distance weighting, which is selected from five interpolation methods. The overall precisions of the constructed velocity field at all stations in the East (E) and, North (N) directions are 0.78 mm/a and 0.95 mm/a, respectively. For evaluating the accuracy of the updated CGCS2000 frame, monthly solutions for the coordinates of some CGCS2000 CORS stations in the ITRF2014 during the period from 2000.0 to 2018 were obtained and the Root Mean Square (RMS) of the differences between the coordinates corrected to the CGCS2000 and the known coordinates at these stations are about 2–3 cm.

Contemporary status of topographic mapping in Ukraine

Abstract The fundamentals and contemporary status of topographic mapping of Ukraine’s territory has been studied. Prior to declaration of Ukraine’s independence, its territory was covered with 1:10,000 to 1:1,000,000 scale topographic maps made by sub-divisions of the Chief Department of Geodesy and Cartography affiliated with the Council of Ministers of the USSR (GUGK USSR) and sub-divisions of the Military Topographic Service (MTS) of the USSR Armed Forces. Topographic mapping related cooperation between these institutions has been described. Topographic study of Ukraine’s territory as at 1991 has been subject to close analysis, with due consideration of the coordinate systems used for topographic maps. During the first years after Ukraine’s independence declaration topographic maps in Ukraine were made according to the previously effective Soviet instructions in the 1942 coordinate systems and 1977 Baltic height system. Since mid 1990s, Ukraine enjoyed transition from analog technology of making topographic maps to digital one. The contemporary legal and statutory support of topographic mapping in Ukraine has been studied; the implementation since 1 January 2007 of the UCS-2000 national geodetic reference coordinate system and the height system measurement works have been analyzed. Focus has been made on obsolescence of information of contemporary topographic maps and on extensive deprivation of secrecy for topographic maps in 2000s. Critical for the development of topographic mapping in Ukraine is now the Law of Ukraine “On National Geospatial Data Infrastructure” adopted in 2020. The Topographic Service of the Armed Forces (TS AF) of Ukraine carried out big scopes of works to update the topographic maps related to Russia’s military operations against Ukraine.

The method for the quality evaluation of open geospatial data for creation and updating of datasets for National Spatial Data Infrastructure in Ukraine

Abstract The purpose of the article is to present the research on method of the quality evaluation of published open geospatial data and its implementation in Ukraine. The method of the quality evaluation of open geospatial data considers the international standard ISO 19157 “Geographic information. Data quality”. This method is to determine the number of points or levels (maximum – 5). The research was carried out for the evaluation of open geoinformation resources for production of geospatial datasets, as defined in the Ukrainian Law on NSDI. The authors evaluated the quality of 142 open geoinformation resources and other information resources (materials) for the production and updating of 34 geospatial datasets for the development of NSDI in Ukraine. The authors present the example of the quality evaluation of geospatial data for datasets: “State Geodetic Reference Coordinate System UCS-2000”, “State Geodetic Network”, “Geographical Names” and “Administrative Units” because they are the components of the Core Reference Dataset of NSDI. Limitations of the research were determined by the adopted the Law of Ukraine “On National Spatial Data Infrastructure” and the Order for NSDI functioning in Ukraine and the requirements of the international standard ISO 19157 “Geographic information. Data quality”. The results of the research will be employed to evaluate the quality of NSDI implementation in Ukraine. The proposed method allows evaluating the quality of open geospatial dataset before using them for analysis and modeling of terrain, phenomena. This method takes into account the quality of geospatial data, and its related requirements for their production, updating and publication.

Combined Positioning Device for the Control System of the Microtunnel Boring Machine

The issues of developing a combined positioning device for the microtunnel boring machine control system are considered. A device combining laser and inertial methods of determining coordinates is proposed, which provides the possibility of determining the coordinates and spatial position of the tunneling shield during the construction of straight and curved tunnels by the pushing method. A method for connecting the positioning device with the microtunnel boring machine control system based on the RS-485 wired interface is proposed. A method for calculating coordinates has been developed that takes into account the rotation of the local coordinate system relative to the local geodetic coordinate system.

Метод розрахунків значень геодезичної дальності, азимута і висоти точки в задачах зовнішньої балістики

У статті розглянуто метод розрахунку значень геодезичної дальності (по поверхні земного еліпсоїда), азимута і висоти точки, координати якої задані в стартовій системі координат (ССК) при вирішенні завдань зовнішньої балістики. Початок ССК визначено в геодезичній системі координат геодезичною широтою, довготою і висотою. Розв'язана задача перетворення значень координат точки з ССК в геодезичну систему координат (ГСК) шляхом проведення послідовних перетворень з ССК в прямокутну геоцентричну систему координат (ПГЦ СК), а потім з ПГЦ СК в ГСК. Особливістю перетворення координат з ССК в ПГЦ СК є додатковий облік складових повного ухилення прямовисній лінії в точці початку ССК. Представлений вивід матриці перетворення координат із ССК в ПГЦ СК. Проведено аналіз впливу неврахування ухилення прямовисній лінії в точці початку ССК на точність обчислень значень геодезичної дальності, азимута і висоти точки. Представлені графіки залежності відносних похибок обчислення значень зазначених величин від величини повного ухилення прямовисній лінії в точці початку ССК. Представлені оцінки абсолютних похибок. Зроблено висновок про необхідність додаткового обліку складових повного ухилення прямовисній лінії в точці початку ССК при проведенні точних обчислень значень геодезичної дальності, азимута і висоти точки, координати якої задані в ССК.

Implementation of virtual reference points in registering scanning images of tall structures

Abstract The concept of obtaining uniform and high-precision 3D models of large and complex engineering structures based on terrestrial laser scanning surveys highly depends on the accuracy of registering a series of adjacent scans. If it is not possible to place the required number of reference points in the observation scene, and there are no identifiable structural elements that could serve as such reference points, the issue can be solved by using the virtual reference points. The virtual reference points are not marked, but their position can be re-created in the post-processing of the scans on the basis of the geometrical features of the object. In the case of an industrial chimney, these can be the structural axis points determined at arbitrarily selected altitudes. In the solution presented herein, the coordinates of the reference points were independently determined twice: in the geodetic coordinate system using traditional method, in the local system of the scanner using the bisector of the chord of the circle, and by approximation of the circular arc shape of the chimney shell. Both procedures are preceded by the filtration of outliers. The concept of virtual reference points was verified by the measurement of the verticality of the axis and the structural geometry of a steel industrial chimney, which was accessible only on the foundation level.

Realization of an Optimal Dynamic Geodetic Reference Frame in China: Methodology and Applications

China Geodetic Coordinate System 2000 (CGCS2000) has been used for several years as a formal published reference frame. The coordinates of all global navigation satellite system (GNSS) stations in China need to be corrected to align with the CGCS2000 frame. Different strategies can be adopted for the realization of an optimal reference frame. However, different strategies lead to different results, with differences as great as several decimeters when GNSS station coordinates are transformed into CGCS2000-defined coordinates. The two common methods for the coordinate correction of a GNSS station are quasi-stable adjustment under CGCS2000 and plate movement correction, and the differences between their results can be greater than 10 cm. In this study, a statistic method called “supervised clustering” is applied to the selection of GNSS reference stations; a new scheme named “partition spacing” for the grouping of all processed GNSS stations is proposed; and the plate movement correction method is used to correct the coordinates of all GNSS stations from the GNSS epoch to the CGCS2000 epoch. The results from the new partitioning method were found to be significantly better than those from the conventional station-blocking approach. When coordinates from the stations without grouping were used as the standard, the accuracy of all the three-dimensional coordinate components from the new partitioning method was better than 2 mm. The root mean squares (RMSs) of the velocities in the x, y, and z directions resulting from the supervised clustering method were 0.19, 0.45, and 0.32 mm∙a−1, respectively, which were much smaller than the values of 0.92, 0.72, and 0.97 mm∙a−1 that resulted from the conventional approach. In addition, singular spectrum analysis (SSA) was used to model and predict the position nonlinear movements. The modeling accuracies of SSA were better than 3, 2, and 5 mm in the east (E), north (N), and up (U) directions, respectively; and its prediction accuracies were better than 5 mm and 1 cm for the horizontal and vertical domains, respectively.

Study on subsidence monitoring technology using terrestrial 3D laser scanning without a target in a mining area: an example of Wangjiata coal mine, China

When using a Terrestrial 3D laser scanning (TLS) to monitor the mining subsidence in a mining area, the conventional methods are to set up the public target manually, or to set up the ground control network in advance. However, these have the disadvantages of high labor intensity and low efficiency. In order to overcome the shortcomings of the conventional methods, this paper presents the subsidence monitoring method using TLS without a target in the mining area. Feature points are used to splice the multi-station point clouds in the same phase, and a few station coordinates are used to uniformly transform the multiphase data into a geodetic coordinate system. Afterwards, the surface digital elevation model (DEM) is established by using the point clouds after coordinate transformation, and the dynamic subsidence value and subsidence basin during the period of observation are obtained by DEM subtraction. Compared to traditional methods, this method simplifies the field measurement process, reduces the labor intensity, and transfers the main work to the internal industry. It is suitable for surface subsidence monitoring with a harsh external environment and complicated topographic conditions. Surface deformation values are important basic data for mining area subsidence parameters acquisition, mining area environmental assessment, land reclamation, and ecological restoration. As a consequence, it is of great value to popularize and apply in mining area for subsidence monitoring.

Precision of satellite based navigation position solution: A review using NavIC data

Global Navigation Satellite System (GNSS) provides all-weather, precise Position, Velocity and Timing (PVT) solutions from any point on the surface or near to the surface of the earth. Accuracy and global availability of solutions are the major important attributes for popularization of the system. Currently, various global and regional system (GPS, GLONASS, Galileo, Beidou, NavIC and QZSS) are in operation. Most of users of GNSS are concerned about the quality of solution obtained from the receivers including the researchers. In some published literature the precision parameters have been obtained from position solution in UTM coordinate. In this paper an attempt has been made to briefly review such efforts and discuss about the parameters used for such studies for geodetic coordinate (φ, λ, h) system because, most generic and geodetic high cost receivers provide this type of position solution. A new effort is taken up to calculate the precision parameters of GNSS based position solution in geodetic coordinate reviewing the previously reported literature. The formulas are reviewed and implemented using MATLAB to develop and utility to calculate precision parameters of satellite-based position solution. A new regional navigation satellite system IRNSS/NavIC, developed by ISRO, India has been deployed. IRNSS/ NavIC data has been analyzed using the developed utility as a case study to observe the effectiveness of such parameters. This discussion and the utility would be useful for understanding the process of GNSS data analysis for studies related to accuracy and precision.

On the transformation of the coordinates of points from the SK-42 system to WGS-84

The significant and effective use of global positioning satellite systems for solution of important theoretical and applied problems of Earth sciences means the preserving of the possibility to use a huge quantity of geodetic, cartographic, gravimetric and other data created on the basis of traditional methods and in different referencing coordinate systems. It is impossible without the correct coordinate transformation at the transition from one system to another. The determination of the coordinates of points using the satellite radio navigation system NAVSTAR GPS is closely related to the world geodetic coordinate system WGS-84. At the same time, data on gravity observations within the Pulkovo 1942 coordinate system have been accumulated in large volumes. It is obvious the need for recalculation of coordinates given in different systems. Information is given on the coordinate systems, geodetic coordinates, units of measurement, display formats for latitude and longitude values. The reference coordinate system of Pulkovo 1942 and the modern world geodetic system WGS-84 are described in sufficient detail. Formulas are given for calculating the normal gravity in these systems. Historical background and classification of coordinate transformation methods are considered. Significant role is given to the high-precision method of Molodensky and the modified Helmert method of coordinate transformation. The standard method of Molodensky is described at the level it is described in official open reports of US government agencies. Programs are considered that automate the solution of the problem of recalculating the coordinates of objects, as well as the issues of transformation of coordinate systems in geographical information systems. The attention is focused on the rash use of the software that might lead to some very strange and inexplicable results.

A Föld alakja és a geodinamika

Az 1960-as évek végén az ELTE Geofizikai Tanszékén megalakult Űrkutató Csoport és a Budapesti Műszaki Egyetem bázisán, nagyrészt diákköri munka keretében kezdődtek meg a hazai Doppler-geodéziai mérések, melyek célja földfelszíni pontoknak a Föld tömegközéppontjához rögzített koordináta-rendszerben történő helymeghatározása volt, műholdas jelek vételével. A jelen munkában összefoglalt kutatás eredményeként a mérési pontok helymeghatározásának pontossága ugyanabba a nagyságrendbe esett és alig maradt el a NASA által ugyanebben az évtizedben az amerikai űrprogram földi követőállomásainak hasonló módszerrel elvégzett helymeghatározásához képest. Ez a munka jelentette Horváth Ferenc kutatói pályafutásának kezdetét. Cikkünk végén bemutatjuk, hogy az űrgeodézia már ebben az időszakban is kapcsolódott a Föld dinamikai szerkezetének megértéséhez.

Agricultural drainage tile surveying using an unmanned aircraft vehicle paired with Real-Time Kinematic positioning—A case study

A 2012 agricultural census reported approximately 218,000 U.S. farms to have subsurface tile networks that artificially drain over 19.7 million hectares. These drainage networks present a significant expense to landowners during their installation, inspection, maintenance, and upgrading. The conventional methods for locating buried drain tiles are by excavation employing heavy machinery and hand tile probes which are expensive and time-consuming.Aerial photography offers promise as a less-expensive alternative for mapping tile networks over vast acreages. In aerial photography, ground-surface discolorations from the concentratio of draining moisture periodically appear directly atop functioning drains. We have noted drainage surface patterns occurring on Midwestern fields with minimal surface residue one to three days following significant rainfall. An unmanned aerial vehicle (UAV) equipped with visible or thermal infrared (TIR) imaging can detect these distortions at appropriate times. Our study compared Real Time Kinematic (RTK) and Wide Area Augmentation System (WAAS) Global Positioning System (GPS) for mapping of subsurface drain tiles.The case study revealed WAAS GPS provided insufficient accuracy and precision for physically locating the buried tiles. Although more expensive and complicated, satellite RTK technology increases the vertical and horizontal alignment of UAV surveys as it projects aerial imagery precisely and accurately onto a geodetic coordinate system. The pairing of RTK technology with the UAV survey was deemed essential for physically locating buried tile lines in the field.

A local projection for integrating geodetic and terrestrial coordinate systems

This paper develops a system for projecting coordinates from a geocentric coordinate system to a topocentric coordinate system defined by terrestrial measurements. The proposed system uses an extension of the Stereographic Double Map Projection and a parametric least squares estimation to calculate the parameters for the map projection. The Extended Stereographic Double Projection and the projection parameter estimation are implemented and tested. Tests are performed to determine rate that discrepancies occur and the maximum extents of the Extended Stereographic Double Projection. This maximum area is determined to be ∼10 km2 with RMS values of residuals of 0.0029 m in northing and 0.0020 m in easting. Tests are also performed to determine the factor that limits the effective area of the Projection.

A grid mapping algorithm for modeling with geometric transforms

The geometries of subsurface deposits are often discordant with the geodetic coordinate system in which drilling, engineering design and operations are performed. To provide superior characterization of a deposit with computational advantages, a common workflow begins by modeling the deposit's geometries, before transforming property data into a local coordinate system. Within this system, the property data is flattened with respect to a regular rectilinear grid, facilitating the effective use of conventional geostatistical modeling algorithms. After back-transforming to a geodetic coordinate system, the gridded model values will not align with the original system. Depending on the nature of the transform, the model values may be converted from a regular grid in local coordinates to a structured grid in geodetic coordinates, where the incremental spacing and shapes of cells are irregular. Most model applications require a regular grid as input, such as within mine planning software and many flow simulators; the structured grid values must therefore be mapped to a regular grid. Practical but sub-optimal methods, such as nearest neighbour, are often used in practice for this mapping. A new method, termed Structured to Regular Grid Mapping (SRGM), is proposed as an alternative. Through the combined use of grid pre-screening, point-in-tetrahedra testing, and sequential planar tests, SRGM provides substantially improved precision and reduced computational expense relative to the nearest neighbour approach. SRGM is introduced with a small example, before demonstrating it with a tabular nickel sulphide deposit. Practical considerations and limitations of SRGM are also discussed.

Automatic tracking and positioning algorithm for moving targets in complex environment

Nowadays, when moving targets are located in complex environment, the positioning algorithm takes longer time, and the result is not consistent with the actual positioning of the moving target, which has the problem of low positioning efficiency and inaccurate positioning results. In this paper, a moving target automatic tracking and positioning algorithm is proposed in the complex environment, which establishes the geodetic coordinate system and the space rectangular coordinate system, and completes the transformation between the geodetic coordinate system and the rectangular coordinate system, so as to improve the accuracy of the positioning result. The signal is rebuilt and the MIMO radar positioning model is used to complete the automatic tracking and positioning of the moving target in complex environment, to reduce the time consuming. The experimental results show that the proposed method can quickly and accurately track and locate the moving target in complex environment.

Geocentric Coordinate Systems and Actual Problems of Modernization of the State Geodetic Network

The article describes the state of the geocentric coordinate system of the Russian Federation. Current problems of the geodetic coordinate system are described, and a method for solving this problem is proposed.

Методика определения нормальных высот по данным спутниковых определений с учётом уклонений отвесной линии

Currently, using in Vietnam for constructing is normal height and method of leveling geometry. During the construction, it is necessary to transfer height through difficult terrain, such as large rivers or high mountains. In such situations, the transfer of altitude with the help of GNSS will allow to reduce labor costs in comparison with the transfer of altitude using the geometric method. However, the key issue is interpret the altitude defined by the GNSS to a normal height with an accuracy that meets the requirements for leveling grids in engineering geodesy. In this article has been offered algorithm for determining normal altitudes from satellite data and taking into account the deviations of the plumb line. Using GNSS technology are determined coordinates in the geodetic coordinate system or in the spatial one corresponding to the ellipsoid WGS-84. The technique for determining the normal heights from the data of satellite determinations is considered. A computational algorithm is proposed that includes taking into account the deviations of the plumb line and their determination by rotation of the ellipsoid, and also assuming the presence of geometric leveling data. An example of the implementation of an algorithm on a specific object is shown.