Research on improved hough algorithm and its application in lunar crater

2021 ◽  
pp. 1-9
Author(s):  
Lanfeng Zhou ◽  
Ling Li
Keyword(s):  
Coordinate System ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Detection Algorithm ◽  
Polar Coordinate System ◽  
Circle Center ◽  
Traditional Algorithm ◽  
Polar Coordinate ◽  
Cartesian Coordinate ◽  
Three Dimensional Space

Traditional Hough circle detection algorithm usually determines the center and radius of a circle by mapping points in cartesian coordinate system to polar coordinate system. Since it accumulates in the three-dimensional space, it requires more calculation consumption. In this paper, we solve the problem of high time complexity of Hough algorithm in judging circle radius and circle center from two aspects of circle angle and circle radius according to the geometric features of quasi-circles. A large number of experiments show that, compared with the traditional algorithm, this algorithm can not only identify quasi-circles, but also improve the detection success rate of circles by about 10%, with efficient running speed, and obtain good experimental results in the detection of craters.

scholarly journals Aerosol Plume Detection Algorithm Based on Image Segmentation of Scanning Atmospheric Lidar Data

2016 ◽  
Vol 33 (4) ◽  
pp. 697-712 ◽  
Author(s):  
R. Andrew Weekley ◽  
R. Kent Goodrich ◽  
Larry B. Cornman
Keyword(s):  
Coordinate System ◽  
Original Data ◽  
Detection Algorithm ◽  
Polar Coordinate System ◽  
Lidar Data ◽  
Image Processing Algorithm ◽  
Polar Coordinate ◽  
Scanning Lidar ◽  
Performance Statistics ◽  
Background Fields

AbstractAn image-processing algorithm has been developed to identify aerosol plumes in scanning lidar backscatter data. The images in this case consist of lidar data in a polar coordinate system. Each full lidar scan is taken as a fixed image in time, and sequences of such scans are considered functions of time. The data are analyzed in both the original backscatter polar coordinate system and a lagged coordinate system. The lagged coordinate system is a scatterplot of two datasets, such as subregions taken from the same lidar scan (spatial delay), or two sequential scans in time (time delay). The lagged coordinate system processing allows for finding and classifying clusters of data. The classification step is important in determining which clusters are valid aerosol plumes and which are from artifacts such as noise, hard targets, or background fields. These cluster classification techniques have skill since both local and global properties are used. Furthermore, more information is available since both the original data and the lag data are used. Performance statistics are presented for a limited set of data processed by the algorithm, where results from the algorithm were compared to subjective truth data identified by a human.

Vehicle Kinematic State Estimation Using Passive Sensor Fusion Approach

2012 ◽  
Vol 271-272 ◽  
pp. 1709-1712 ◽  
Author(s):  
Li Wei Fong ◽  
Pi Ching Lou ◽  
Ke Jia Tang
Keyword(s):  
Coordinate System ◽  
Autonomous Navigation ◽  
Weighted Least Squares ◽  
Hierarchical Architecture ◽  
Estimation Accuracy ◽  
Polar Coordinate System ◽  
Global Estimate ◽  
Polar Coordinate ◽  
Passive Sensor ◽  
Cartesian Coordinate

The main issue addressed here is that of estimating the kinematic state components of a vehicle in autonomous navigation using landmark angle-only measurements from an onboard passive sensor. The estimates of the absolute position and velocity of the vehicle are provided by a hybrid coordinate fusion filter. The hierarchical architecture of the filter which consists of a group of local processors and a global processor is developed for improving estimation accuracy. In each local processor, an extended Kalman filter uses hybrid information from the reference Cartesian coordinate system and the modified polar coordinate system for state and state error covariance extrapolation and updating. In the global processor, a weighted least squares estimator is utilized to combine the outputs of local processors to form a global estimate. By using only two landmarks simulation results show that proposed algorithm improves the estimation accuracy drastically.

scholarly journals Determination of Ship Approach Parameters in the Polar Coordinates System

2014 ◽  
Vol 96 (1) ◽  
pp. 1-8
Author(s):  
Andrzej Banachowicz ◽  
Adam Wolski
Keyword(s):  
Coordinate System ◽  
Target Position ◽  
Geometric Interpretation ◽  
Polar Coordinates ◽  
Polar Coordinate System ◽  
Polar Coordinate ◽  
Radar Measurements ◽  
Cartesian Coordinate ◽  
Radar Antenna

Abstract An essential aspect of the safety of navigation is avoiding collisions with other vessels and natural or man made navigational obstructions. To solve this kind of problem the navigator relies on automatic anti-collision ARPA systems, or uses a geometric method and makes radar plots. In both cases radar measurements are made: bearing (or relative bearing) on the target position and distance, both naturally expressed in the polar coordinates system originating at the radar antenna. We first convert original measurements to an ortho-Cartesian coordinate system. Then we solve collision avoiding problems in rectangular planar coordinates, and the results are transformed to the polar coordinate system. This article presents a method for an analysis of a collision situation at sea performed directly in the polar coordinate system. This approach enables a simpler geometric interpretation of a collision situation

Using a Polar Coordinate System in the Classroom

1990 ◽  
Vol 37 (8) ◽  
pp. 42-45
Author(s):  
William M. Carroll
Keyword(s):  
Elementary School ◽  
Coordinate System ◽  
School Level ◽  
Polar Coordinate System ◽  
School Students ◽  
Rectangular Coordinate System ◽  
Polar Coordinate ◽  
Supplementary Material ◽  
Cartesian Coordinate ◽  
Additional Exposure

Most elementary school students have experiences with a rectangular graphing system that helps to prepare them for ideas in algebra and analytic geometry. Mathematics books at the elementary school level contain a section on graphing, though it is often one of the later chapters, where it may be treated as supplementary material. In science and in social studies, students may find various data graphed or may have a project in which they have to graph daily temperatures, rainfall, or test scores. Biorhythms, record sales charts, or, for the more ambitious, the daily stock market give additional exposure. Designing graphics on the computer monitor often requires some placement by a rectangular coordinate system. By the time students meet the Cartesian coordinate system with its x- and y-axes and use it to graph equations, the idea and techniques should be somewhat familiar.

scholarly journals Lane Detection Algorithm Using LRF for Autonomous Navigation of Mobile Robot

2021 ◽  
Vol 11 (13) ◽  
pp. 6229
Author(s):  
Jong-Ho Han ◽  
Hyun-Woo Kim
Keyword(s):  
Mobile Robot ◽  
Autonomous Navigation ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Detection Algorithm ◽  
Lane Detection ◽  
Detection And Tracking ◽  
Lane Recognition ◽  
Fundamental Requirement ◽  
Three Dimensional Space

This paper proposes a lane detection algorithm using a laser range finder (LRF) for the autonomous navigation of a mobile robot. There are many technologies for ensuring the safety of vehicles, such as airbags, ABS, and EPS. Further, lane detection is a fundamental requirement for an automobile system that utilizes the external environment information of automobiles. Representative methods of lane recognition are vision-based and LRF-based systems. In the case of a vision-based system, the recognition of the environment of a three-dimensional space becomes excellent only in good conditions for capturing images. However, there are so many unexpected barriers, such as bad illumination, occlusions, vibrations, and thick fog, that the vision-based method cannot be used for satisfying the abovementioned fundamental requirement. In this paper, a three-dimensional lane detection algorithm using LRF that is very robust against illumination is proposed. For the three-dimensional lane detection, the laser reflection difference between the asphalt and the lane according to color and distance has been utilized with the extraction of feature points. Further, a stable tracking algorithm is introduced empirically in this research. The performance of the proposed algorithm of lane detection and tracking has been experimentally verified.

scholarly journals The system of acquisition and archiving of motion parameters of mobile systems - an overview of measuring sensors

2019 ◽  
Vol 20 (1-2) ◽  
pp. 234-240
Author(s):  
Jakub Grabiński ◽  
Konrad Waluś
Keyword(s):  
Coordinate System ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Mobile Systems ◽  
Measuring System ◽  
Starting Point ◽  
Macro Scale ◽  
Mems Technology ◽  
Motion Parameters ◽  
Cartesian Coordinate

As part of the work, a measuring system is presented that allows collecting and recording vehicle motion parameters. To build the system, an inertial navigation module was used, consisting of two-axis accelerometers and gyroscopes made in MEMS technology. The tests were carried out and calculation methods were developed to allow the collected data to be referenced, to a point in the three-dimensional space, in order to determine the trajectory of the vehicle's movement. The built-in measuring system uses three types of sensors: accelerometer, gyroscope, magnetometer. Each of these sensors allows the measurement of the physical size in three orthogonal axes of the Cartesian coordinate system. In addition, the work uses a satellite navigation module (GPS), as a reference on the "macro" scale (coordinate system related to the center of the globe with a radius of about 6371 km) for the inertial updating module (INS / IMU), enabling accurate measurement in the "micro" scale (the coordinate system associated with the starting point of the traffic for the route, the length of which does not exceed several hundred meters). The article presents an overview of available measuring sensors with special consideration of the parameters of selected sensors and errors introduced into the measurement system.

Stress Calculation of Gravity Dam Based on Elastic Mechanics

2012 ◽  
Vol 238 ◽  
pp. 256-259
Author(s):  
Hai Bo Cui ◽  
Hai Tang Zhu ◽  
Jin Chao Yue
Keyword(s):  
Coordinate System ◽  
Superposition Principle ◽  
Equivalent Stress ◽  
Gravity Dam ◽  
Polar Coordinate System ◽  
Polar Coordinate ◽  
Cartesian Coordinate ◽  
Dimensional Analysis Method ◽  
Water Lever ◽  
Elastic Mechanics

Based on the elastic mechanics theory, combined with Saint-Venant principle and the superposition principle, the calculating method for the stress of gravity dam in arbitrary storage water lever were put forward by means of the equivalent stress method and the dimensional analysis method through the conversion between a Cartesian coordinate system and Polar coordinate system. The method not only offers a new idea for calculating the stress of gravity dam, but also presents research bases for evaluating synthetically the strength of gravity dam.

Research on Copy-Move Image Forgery Detection Using Features of Discrete Polar Complex Exponential Transform

2015 ◽  
Vol 25 (14) ◽  
pp. 1540018 ◽  
Author(s):  
Yanfen Gan ◽  
Junliu Zhong
Keyword(s):  
Coordinate System ◽  
Polar Coordinate System ◽  
Forgery Detection ◽  
Rotation Invariant ◽  
Image Forgery ◽  
Polar Coordinate ◽  
Exponential Transform ◽  
Cartesian Coordinate ◽  
Polar Complex Exponential Transform ◽  
Complex Exponential

With the aid of sophisticated photo-editing software, such as Photoshop, copy-move image forgery operation has been widely applied and has become a major concern in the field of information security in the modern society. A lot of work on detecting this kind of forgery has gained great achievements, but the detection results of geometrical transformations of copy-move regions are not so satisfactory. In this paper, a new method based on the Polar Complex Exponential Transform is proposed. This method addresses issues in image geometric moment, focusing on constructing rotation invariant moment and extracting features of the rotation invariant moment. In order to reduce rounding errors of the transform from the Polar coordinate system to the Cartesian coordinate system, a new transformation method is presented and discussed in detail at the same time. The new method constructs a [Formula: see text] shrunk template to transform the Cartesian coordinate system back to the Polar coordinate system. It can reduce transform errors to a much greater degree. Forgery detection, such as copy-move image forgery detection, is a difficult procedure, but experiments prove our method is a great improvement in detecting and identifying forgery images affected by the rotated transform.

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