Ambiguous Solutions Research Articles

‘The politics of analogies’: changing Western views on Kosovo’s final status during NATO’s military intervention in 1999

The article explores the Western discourse on the Kosovo crisis, in 1998–1999, using recently declassified sources that shed light on the internal deliberations and decision-making process on the territory’s future status. While the Western powers became increasingly critical of Serbian president Slobodan Milošević’s military crackdown in Kosovo, their policy did not change from the beginning of the crisis in early 1998 to NATO’s military intervention in March 1999. It foresaw an ambiguous solution based on the status quo ante, restoring Kosovo’s autonomy within the Federal Republic of Yugoslavia to be imposed by the Western powers, with Russia’s blessing, and backed by the threat of airstrikes against Serbia. It is shown, however, that during the Kosovo War, British prime minister Tony Blair began advocating for Kosovoʼs independence, with considerable support from his U.S., German, and French counterparts, even if the formal Western policy remained unchanged. This development was linked to NATO’s intervention, which forced the Serbian military and police forces to leave Kosovo but did not end Milošević’s grip on power in Serbia. With the establishment of a post-war UN protectorate, Serbian sovereignty over Kosovo was suspended, which a decade later formed the basis for its independence declaration.

GPS Phase Integer Ambiguity Resolution Based on Eliminating Coordinate Parameters and Ant Colony Algorithm.

Correctly fixing the integer ambiguity of GNSS is the key to realizing the application of GNSS high-precision positioning. When solving the float solution of ambiguity based on the double-difference model epoch by epoch, the common method for resolving the integer ambiguity needs to solve the coordinate parameter information, due to the influence of limited GNSS phase data observations. This type of method will lead to an increase in the ill-posedness of the double-difference solution equation, so that the fixed success rate of the integer ambiguity is not high. Therefore, a new integer ambiguity resolution method based on eliminating coordinate parameters and ant colony algorithm is proposed in this paper. The method eliminates the coordinate parameters in the observation equation using QR decomposition transformation, and only estimates the ambiguity parameters using the Kalman filter. On the basis that the Kalman filter will obtain the float solution of ambiguity, the decorrelation processing is carried out based on continuous Cholesky decomposition, and the optimal solution of integer ambiguity is searched using the ant colony algorithm. Two sets of static and dynamic GPS experimental data are used to verify the method and compared with conventional least squares and LAMBDA methods. The results show that the new method has good decorrelation effect, which can correctly and effectively realize the integer ambiguity resolution.

Baseline-constrained single-epoch GNSS attitude determination using a priori attitude information

Instantaneous Global Navigation Satellite System (GNSS) attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied, particularly the one using a priori attitude information replacing the code measurements to enhance the successful rate for ambiguity resolution. However, there exists a key limitation that this method relies on considerable Monte Carlo sampling particles to construct the pdf of ambiguities, resulting in significant computational burdens. To address this limitation, this paper provides a rapid single-epoch GNSS attitude determination method based on a priori attitude information. It utilizes a second-order Taylor expansion to analytically estimate the covariance of the baseline conditioned on a priori attitude information. This is followed by deriving the float solution and covariance of ambiguities, which are then processed using the standard LAMBDA method for integer ambiguity resolution. Experimental results demonstrate that our method is both efficient and accurate, significantly reducing computational costs compared to previous methods, thereby enhancing its applicability for GNSS-based attitude determination.

Phase residuals analysis in kinematic orbit determination of GRACE-FO

The GRACE-FO based scientific research will benefit from the improvement of the kinematic orbit quality. This study investigated the errors that could potentially impact the accuracy of orbit determination and applied error corrections to the observations, including phase center variation (PCV) and multipath error, with a specific focus on enhancing the performance of GRACE-FO kinematic precise orbit determination based on the zero-difference method. When the observation model for precise orbit determination is highly consistent with the actual situation, the phase residuals should only consist of observation noise. However, the phase residuals encompass both modeled errors and unmodeled errors, such as PCV and multipath errors. The study utilized the GPS observation data of the GRACE-FO satellites in January 2022 to derive the fixed ambiguity solutions based on the zero-difference ionosphere-free linear combination, thereby obtaining the phase residuals. Subsequently, the antenna PCV was estimated based on the residual method, resulting in a substantial reduction in carrier phase residuals through PCV correction. A comparison with the reference orbits revealed that the root mean square (RMS) of the fixed solutions with PCV correction improved by 2.8 to 4.3 mm in three directions. Furthermore, the wavelet decomposition was performed on the phase residuals to extract the multipath errors and reconstruct the carrier phase observations. The RMS of the kinematic orbits improved by 4.3 to 5.9 mm with the incorporation of both the PCV and multipath error corrections. The RMS of the satellite laser ranging (SLR) residuals of the two GRACE-FO (GRACE-C and GRACE-D) satellites were 1.43 cm and 1.48 cm, respectively. The results indicate that these methods have the potential to enhance the kinematic orbit accuracy of the GRACE-FO satellites, bringing it closer to the a posteriori scientific orbit accuracy.

A theoretical analysis of the logging-while-drilling dipole acoustic reflection measurement

Post-drilling wireline acoustic single-well imaging technology can now detect geological structures tens of meters away from boreholes. Further development of this single-well imaging technology in the logging-while-drilling (LWD) environment will have significant values in real-time applications such as geosteering and reservoir navigation. Based on the wireline imaging application, we propose a new method for the LWD application. In wireline imaging, the four-component (4C) dipole acoustic data are azimuthally rotated to scan the reflectors around the borehole. In LWD, azimuthal scanning is achieved by drilling rotation such that the 4C dipole system in the wireline is replaced by a one-dipole-source and two-receiver LWD system, where the two receivers are mounted on opposite sides of the drill collar. For the LWD application, we first developed the theory for LWD dipole shear-wave reflection imaging and validated the theory using 3D finite-difference waveform modeling. Using the analytical solution, we analyzed the far-field radiation directivity of an acoustic LWD dipole source and the effect of drilling rotation on the shear-wave reflection imaging using the LWD acoustic system. The LWD analysis results show that, for fast formations, the SH-wave is the dominant component for imaging, whereas for slow formations, the P-wave becomes important and can be used for imaging. Our results also indicate that the reflection data acquired by the system are affected by the speed of drilling rotation. The take-off azimuth at the wave radiation may be different from the incident azimuth at the wave reception. Knowing the rotation speed, this azimuth difference can be corrected. A further advantage of using the oppositely mounted receivers is that the reflected wave arrives earlier (later) at the front (back)-side receiver; thus, the arrival time difference between the receivers can be used to eliminate the 180°-azimuth ambiguity of dipole acoustic imaging. For reflection imaging, using the proposed LWD system configuration, we tested its azimuth sensitivity and validated its 180°-ambiguity solution using synthetic LWD and field wireline dipole data. The results of this work, therefore, provide a theoretical foundation for the development of the LWD acoustic reflection imaging system.

Sobornost as a non-sociological category

The article is devoted to the reconstruction of the concept “conciliarity” (“sobornost”) and is motivated by its incorrect, in the author’s opinion, use in modern sociological literature. Having put forward the understanding of sobornost as a transcendent / socially loaded category as the main dilemma, the author gives an ambiguous solution to it. It is shown that the concept of sobornost, the appearance of which in Russian religious philosophy and, more broadly, Russian culture, is traditionally associated with the name of A. S. Khomyakov, is deeply rooted in the religious-mystical experience of the latter and requires careful handling. Sobornost, in its authentic understanding, is the divine grace that descended upon the meeting of believers and mystically transformed it. This concept belongs to the theological picture of the world; bringing it into sociological analysis is incorrect, and its use in socio-political discourse is unwholesome, since it sets false guidelines and values. At the same time, the vulgarization of the notion of “sobornost” present in many works can be explained not only by a superficial and / or tendentious reading, but also by the inherent deep ambivalence of this concept, the obvious gaps between its authentic content and latent mental constructs embedded in it and analytically revealed by a certain research perspective. “Sobornost” was born as a social, in its basic intuitions, category, and in its historical development it returns to these intuitions. The presence of a certain connection between the deeply mystical authentic content of “conciliarity” and its social projections, as well as its subsequent sociologically inevitable secularization, turns the concept under consideration into an extremely curious object of terminological analysis.

Investigation of the accuracy of BeiDou, QZSS and QZSS/BeiDou satellites configuration for short, medium and long baselines in the Asia-Pacific regions

Abstract The field of satellite navigation has seen significant advancements due to the fast development of multi-constellation Global Navigation Satellite Systems (GNSS). Around 150 satellites will be in service when all six systems – GPS, GLONASS, Galileo, BeiDou, QZSS, and NAVIC – are launched by 2030, offering both enormous potential and advantages for research and engineering applications. This study used an experiment on the accuracy, particularly for short, medium, long baselines (Wide Lane ambiguity solution) of the BeiDou, QZSS and QZSS/BeiDou combinations. It showed that with the integration of BeiDou/QZSS static measurements in the study region millimetre-centimetre accuracy for short, medium, and long baselines can be attained. Based on the results of this study, it can be concluded that the 1st (QZSS/BeiDou), 2nd (BeiDou), and 3rd (QZSS) strategies feature different horizontal accuracies for all categories. The obtained results with different satellite configurations for the Fixed-Wide-Lane integer ambiguity solution are compared with each other. Accuracy at the short baseline (BeiDou, QZSS, and BeiDou/QZSS satellites) was obtained in the range of 0.5–0.7 cm. For the medium baseline, it was computed around 1.8–82 cm. For the long baseline, the accuracy was 5.6–13.3 cm.

Adaptive track approach for multiple sources scenarios during radar survey for space surveillance applications

The increasing population of resident space objects is currently fostering many space surveillance initiatives, which rely on the use of on-ground sensors. In particular, survey radars allow to first characterise the target orbit from a single transit, through measurements which are Doppler shift, slant range and angular profile. In this framework, the Music Approach for Track Estimate and Refinement (MATER) algorithm was developed to compute the angular track through the MUltiple SIgnal Classification (MUSIC), by solving possible ambiguities which may arise because of the receiver array geometry.This work presents the MATER extension to the case in which multiple sources are simultaneously detected by the sensor. For each detected source, the signal Direction of Arrival (DOA) is computed through MUSIC, and, if no prediction is exploited, possible ambiguous solutions arise. The computation is repeated for the entire observation, and all the estimations related to a specific target are grouped based on the angular sequence shape and the detection epochs. Finally, the possible ambiguity problem is solved, and the angular profile is obtained through a quadratic regression in time.The algorithm is numerically tested on a survey observation simulation. The detection length depends on the impinging signal intensity, and the angular accuracy is in the order of 1e-03 deg. A sensitivity analysis highlights that a transmitted power decrease shortens the detection length, with no remarkable angular accuracy deterioration. An additional simulation shows that in proximity operation monitoring MATER performance depends on the mutual geometry between target and chaser, as it may bring down the reciprocal angular distance under the resolution level. Nevertheless, it is always possible to identify the presence of both sources through the eigenvalues analysis of the signal correlation matrix. Finally, the simulation of a fragments cloud observation highlights that MATER performance depends both on the size of the observed fragment, as this is strictly linked to the signal detected by the receiver, and on the simultaneous detection of other fragments with a more effective signal.

EPro-PnP: Generalized End-to-End Probabilistic Perspective-N-Points for Monocular Object Pose Estimation.

Locating 3D objects from a single RGB image via Perspective-n-Point (PnP) is a long-standing problem in computer vision. Driven by end-to-end deep learning, recent studies suggest interpreting PnP as a differentiable layer, allowing for partial learning of 2D-3D point correspondences by backpropagating the gradients of pose loss. Yet, learning the entire correspondences from scratch is highly challenging, particularly for ambiguous pose solutions, where the globally optimal pose is theoretically non-differentiable w.r.t. the points. In this paper, we propose the EPro-PnP, a probabilistic PnP layer for general end-to-end pose estimation, which outputs a distribution of pose with differentiable probability density on the SE(3) manifold. The 2D-3D coordinates and corresponding weights are treated as intermediate variables learned by minimizing the KL divergence between the predicted and target pose distribution. The underlying principle generalizes previous approaches, and resembles the attention mechanism. EPro-PnP can enhance existing correspondence networks, closing the gap between PnP-based method and the task-specific leaders on the LineMOD 6DoF pose estimation benchmark. Furthermore, EPro-PnP helps to explore new possibilities of network design, as we demonstrate a novel deformable correspondence network with the state-of-the-art pose accuracy on the nuScenes 3D object detection benchmark. Our code is available at https://github.com/tjiiv-cprg/EPro-PnP-v2.

Improved GNSS Ambiguity Fast Estimation Reduction Algorithm.

The fast and accurate solution of integer ambiguity is the key to achieve GNSS high-precision positioning. Based on the lattice theory of high-dimensional ambiguity solving, the reduction time consumption is much larger than the search time consumption, and it is especially important to improve the efficiency of the lattice basis reduction algorithm. The Householder QR decomposition with minimal column pivoting is utilized to pre-sort the basis vectors and reduce the number of basis vector exchanges during the reduction process by partial size reduction and relaxing the basis vector exchange condition to improve the reduction efficiency of the LLL algorithm. The improved algorithm is validated using simulated and measured data, respectively, and the performance advantages and disadvantages of the improved algorithm are evaluated from the perspectives of the extent of reduction basis orthogonality and the quality of reduction basis size reduction. The results show that the improved LLL algorithm can significantly reduce the number of basis vector exchanges and the reduction time consumption. The HSLLL and PSLLL algorithms with the Siegel condition as the basis vector exchange condition have a better reduction effect, but are slightly less stable. The PLLLR algorithm significantly improves the search ambiguity resolution efficiency, which is conducive to the rapid realization of ambiguity resolution.

Improved Multi-GNSS PPP Partial Ambiguity Resolution Method Based on Two-Step Sorting Criterion

Multi-GNSS PPP partial ambiguity resolution (PAR) can improve the fixing success rate and shorten the time to first fix (TTFF). Ambiguity subset selection based on the bootstrapping success rate sorting criterion (BSSC) is widely used in PPP PAR due to its ease of computation and comprehensive evaluation of the global quality of ambiguity solutions. However, due to the influence of unmodeled errors, such as atmospheric residuals and gross errors, ambiguity parameter estimation will inevitably introduce bias. For ambiguity parameters with bias, their variance will converge incorrectly and will not accurately reflect the estimation accuracy. As a result, the selected ambiguity subset based on the BSSC becomes inaccurate, affecting the fixing success rate and TTFF. Therefore, we proposed an improved multi-GNSS PPP PAR method based on a two-step sorting criterion (TSSC). This method aims to address the influence of inaccurate variance of ambiguity parameters, particularly those with low observation quality, on the ambiguity subset selection based on the BSSC. The ambiguity subset satisfying the preset success rate threshold is selected to reduce the influence of unconverged ambiguity on the TSSC. In the first step of the sorting process, the observations whose elevation angle is below 30° or whose posterior residual falls into the IGG3 model reduction domain are clustered together. The posterior observation weight criterion (POWC) instead of the BSSC is adopted to sort ambiguities to overcome the false convergence of variance of ambiguity parameters. In the second step of the sorting process, the remaining ambiguities with reasonable variances are sorted based on the BSSC. Finally, the bottom ambiguity is removed one by one from the ambiguity subset sorted based on the two-step sorting criterion (TSSC) until the requirements of the ratio test for LAMBDA are met. The static data from 10 MGEX stations over a period of 30 days, along with urban kinematic data, were collected to validate the proposed method. Compared with the PAR based on the BSSC, the static experiments demonstrated a reduction of 8.7% and 16.8% in the TTFF and convergence time, respectively. Additionally, the positioning accuracy in the east, north, and up directions was improved by 20.1%, 17.1%, and 4.67%, respectively. Furthermore, the kinematic experiment revealed that the TTFF and convergence time decreased from 1.65 min and 10.5 min to 1.3 min and 1.8 min, respectively, with higher positioning accuracy.

AVALIAÇÃO DA ACURÁCIA DA TÉCNICA DE POSICIONAMENTO GNSS PPP-RTK COM O USO DO SERVIÇO DE CORREÇÃO TRIMBLE CENTERPOINT RTX

The use of only one receiver at the user level, together with the solution of phase ambiguities as integer values, are among the main advantages of the PPP-RTK GNSS Positioning Technique. However, it is necessary to have a Geodetic Network at a global level for the generation of products, such as precise orbits and satellite clocks. Furthermore, to accurately estimate geodetic coordinates, all errors involved with the propagation of GNSS signals and with ground stations must be properly modeled and treated. Thus, the main objective of this work is to evaluate the accuracy of the PPP-RTK Positioning Technique, using corrections from the Trimble Centerpoint RTX Service in Brazil. For this, GNSS surveys were carried out in all states of the Federation in Geodetic Stations belonging to the SGB, whose coordinates were considered as reference in the evaluation process. Student's t statistical tests were applied – to detect possible trends (systematic errors) in the data, and Chi-Square to assess the precision of the coordinates. Finally, the results show that the horizontal accuracy improves gradually with increasing convergence time, reaching 0.025m ± 0.018m (Trend and Precision) for 15 minutes of convergence.

Ambiguous solutions of a Pell equation

Ambiguous solutions of a Pell equation

Improved GNSS integer ambiguity resolution method based on the column oriented Cholesky decomposition

Because the traditional Cholesky decomposition algorithm still has some problems such as computational complexity and scattered structure among matrices when solving the GNSS ambiguity, it is the key problem to further improve the computational efficiency of the least squares ambiguity reduction correlation process in the carrier phase integer ambiguity solution. But the traditional matrix decomposition calculation is more complex and time-consuming, to improve the efficiency of the matrix decomposition, in this paper, the decomposition process of traditional matrix elements is divided into two steps: multiplication update and column reduction of square root calculation. The column reduction step is used to perform square root calculation and column division calculation, while the update step is used for the update task of multiplication. Based on the above ideas, the existing Cholesky decomposition algorithm is improved, and a column oriented Cholesky (C-Cholesky) algorithm is proposed to further improve the efficiency of matrix decomposition, so as to shorten the calculation time of integer ambiguity reduction correlation. The results show that this method is effective and superior, and can improve the data processing efficiency by about 12.34% on average without changing the integer ambiguity accuracy of the traditional Cholesky algorithm.

A survey for variable young stars with small telescopes – VII. Spot properties on YSOs in IC 5070

ABSTRACTWe present measurements of spot properties on 31 young stellar objects, based on multiband data from the HOYS (Hunting Outbursting Young Stars) project. On average the analysis for each object is based on 270 data points during 80 d in at least three bands. All the young low-mass stars in our sample show periodic photometric variations. We determine spot temperatures and coverage by comparing the measured photometric amplitudes in optical bands with simulated amplitudes based on atmosphere models, including a complete error propagation. 21 objects in our sample feature cool spots, with spot temperatures 500–2500 K below the stellar effective temperature (Teff), and a coverage of 0.05–0.4. Six more have hot spots, with temperatures up to 3000 K above Teff and coverage below 0.15. The remaining four stars have ambiguous solutions or are AA Tau-type contaminants. All of the stars with large spots (i.e. high coverage >0.1) are relatively cool with Teff < 4500 K, which could be a result of having deeper convection zones. Apart from that, spot properties show no significant trends with rotation period, infrared excess, or stellar properties. Most notably, we find hot spots in stars that do not show K − W2 infrared excess, indicating the possibility of accretion across an inner disc cavity or the presence of plage.

THE PERFORMANCE ANALYSIS OF THE POST-MISSION WEB-BASED STATIC AND KINEMATIC PPP-AR SERVICE

The use of the Precise Point Positioning (PPP) technique has become very advantageous with the development of GNSS positioning technology. It is possible to get highly accurate position information without the need of any reference station data using the PPP technique. However, there are various factors that affect the accuracy of PPP solutions, including the initial phase ambiguity solution type, which can be fixed or float, atmospheric effects, observation length, used satellite systems, and used precise products. The Canadian Spatial Reference System-Precise Point Positioning (CSRS-PPP) service, one of the online PPP services, was updated on October 20th, 2020, and upgraded to version 3, capable of the Ambiguity-Fixed (PPP-AR) solution. Prior to this date, the service had offered the Ambiguity-Float (PPP-Float) solution. In this study, it is aimed to investigate the effect of using different satellite systems (GPS, GPS&GLONASS), length of observation time, static/kinematic processing modes, and initial phase ambiguity solution types on PPP accuracy. The daily observation data of ANKR, ISTA, IZMI, MERS, and KRS1 IGS GNSS stations located within the borders of Türkiye, divided into different sub-sessions (1-hour, 2-hours, 4-hours, 8-hours, and 12-hours) were processed using CSRS-PPP web-based service as PPP-Float before the update and PPP-AR after the update. As a result of the comparison, the combined use of GPS & GLONASS satellite systems instead of using GPS satellites alone has increased horizontal and vertical accuracy in both static/kinematic PPP-Float and PPP-AR solutions. Considering the static solutions, horizontal and vertical position accuracies increase as the observation time increases in both ambiguity solution methods using different constellations. In the case of comparison of the ambiguity solution methods, it was found that the PPP-AR approach offered higher accuracy than the PPP-Float in all solution cases.

Determination method for ambiguous correct solution of optical single-station pose processing

因单站成像的信息欠缺以及成像的对称性，光学单站姿态处理的二义性是普遍性难点问题，针对光学单站姿态处理二义性解问题，以目标主体直线矢量与姿态角对应关系为突破点，以主体直线矢量的物像映射关系为单站姿态处理基础，从处理结果界定局部二义性错误解，然后根据单站姿态求解关键步骤修正二义性解，修正前后处理结果与常规交会处理结果比较效果显著，在文中所述场景下，误差量级至少缩小20%，该方法为光学单站姿态处理获取正确解提供了可靠理论支持。

A non-iterative calibration method for the extrinsic parameters of binocular stereo vision considering the line constraints

The calibration accuracy of the binocular stereo vision system is important for precision measurement. The extrinsic parameters (structure parameters), which describe the relative position of the two cameras, need to be optimized before measurement. The optimization of extrinsic parameters is accomplished through iterations of minimizing an objective function. It is hard to decide the optimum objective function between various objective functions. The calibration accuracy is decreased when the objective function is incorrect, which can result in excessive optimization or fall into a local minimum (ambiguous solution), notably for planar targets. In this paper, we proposed a non-iterative calibration method for the extrinsic parameters of binocular stereo vision considering the line constraints of a planar target. Each line formed by every two calibration points can provide two independent constraints. Additional equations for solving the extrinsic parameters can be obtained using these constraints. We added these equations to the equations system established by the homography of the target plane and image plane. The extrinsic parameters of the binocular stereo vision system can be solved non-iteratively. Using the parameters calibrated by our method, greater improvements in the accuracy and stability of measurements occurred, compared to other existing methods. In the −45° to +45° measuring range, the maximum measurement error is no more than 0.037° and the average measurement error is no more than 0.022°. In the 0 to 28 mm measuring range, the maximum measurement error is no more than 0.039 mm and the average measurement error is no more than 0.012 mm. The maximum length measurement error is no more than 0.038 mm and the average length measurement error is no more than 0.011 mm while measuring a 240 × 180 mm2 target.

Design of double layer protective coatings: Finite element modeling and machine learning approximations

Thin film-composed coatings can significantly improve the mechanical and tribological properties of spacecraft friction units. In this regard, protection by ion-plasma coatings has become one of the most used options and well-established technologies. However, design of coatings that remain effective over multiple usages, is a challenge. Improving their production requires a large number of parameters to be optimized and many verification experiments to be set up. We exploited machine learning algorithm to solve the problem of double layer coatings optimization with respect to a set of mechanical properties (hardness, Young's modulus, Poisson's ratio, and yield stress). The training dataset was constructed using the adaptive sampling algorithm and numerical simulation of indentation in ANSYS for coatings of different compositions and thicknesses. The machine learning approximation provided significant accuracy (R2 > 0.96) in predicting the coating hardness based on the mechanical properties of its individual layers. The feature importance analysis of the Extra Trees algorithm was used to define the parts of the indentation curve that carry information about the properties of individual coating layers. We have also addressed the inverse problem of coatings design in terms of the required hardness. Our findings demonstrate that only tandem approach to the cross-validation task permitted correct estimation of error in the presence of multiple ambiguous solutions. The value of error was smaller than 0.15 GPa. Being comprehensive, the proposed methodology can be applied to design optimal multilayer coatings in terms of their mechanical properties for friction units in aviation and rocketry-astronautics.

Urban Traffic Imaging Using Millimeter-Wave Radar

Imaging technology enhances radar environment awareness. Imaging radar can provide richer target information for traffic management systems than conventional traffic detection radar. However, there is still a lack of research on millimeter-wave radar imaging technology for urban traffic surveillance. To solve the above problem, we propose an improved three-dimensional FFT imaging algorithm architecture for radar roadside imaging in urban traffic scenarios, enabling the concurrence of dynamic and static targets imaging. Firstly, by analyzing the target characteristics and background noise in urban traffic scenes, the Monte-Carlo-based constant false alarm detection algorithm (MC-CFAR) and the improved MC-CFAR algorithm are proposed, respectively, for moving vehicles and static environmental targets detection. Then, for the velocity ambiguity solution problem with multiple targets and large velocity ambiguity cycles, an improved Hypothetical Phase Compensation algorithm (HPC-SNR) is proposed and complimented. Further, the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm is used to remove outliers to obtain a clean radar point cloud image. Finally, traffic targets within the 50 m range are presented as two-dimensional (2D) point cloud imaging. In addition, we also try to estimate the vehicle type by target point cloud size, and its accuracy reaches more than 80% in the vehicle sparse condition. The proposed method is verified by actual traffic scenario data collected by a millimeter-wave radar system installed on the roadside. The work can support further intelligent transportation management and extend radar imaging applications.