Table of Content

20 July 2014, Volume 43 Issue 7

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Twin-satellites altimetry mode and its orbit design

2014, 43(7):  661-667. 

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To enhance the resolution of recovery of marine gravity field from satellite altimeter, we proposed a new twin-satellites altimetry mode in this paper. A detailed orbit design is also presented following the basic requirements of satellite’s orbit design. It is also demonstrated that the 1 min marine altimetry gravity field can be derived to satisfy the requirement of high resolution. The observation of twin-satellite will cover most of the oceans and seas of the Earth. Besides the sea surface height observations, the new model will provide two components of deflection of verticals along the track, which will contribute to the improvement of accuracy of marine altimetry gravity field.

An Iterative Algorithm for Nonlinear Total Least Squares Adjustment

2014, 43(7):  668-674. 

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Evaluation of the Survey Line Layout with Interpolation Precision Between the Adjacent Lines in Marine Magnetic Survey

2014, 43(7):  675-680. 

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The survey line layout is the primary content of the technique design in marine magnetic survey. The problems of the survey line layout in marine magnetic survey of our country have been analyzed. The evaluating method of the survey line layout with the interpolation precision between the adjacent lines has been put forward. The result show that the interpolation precision between the adjacent survey lines can be applied in the analyzing the affect of the survey line layout to the survey and can be used to evaluate the rationality of the survey line layout, which can provide the basis of the optimizing of the survey line layout.

A Method for Streamlining and AssessingSound VelocityProfilesBased onImproved D-P Algorithm

2014, 43(7):  681-689. 

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Sound velocity profilesare indispensable in the multi-beam sounding. In order to solve problem thatthe amount of originalmeasured sound velocity profiles affect efficiency, this article focuses on sound velocity profile streamlining and optimization, presentinga improved D-P algorithm(MOV method)suitable for streamlining sound velocity profiles, assessing sounding accuracy before and after streamlining sound velocity profilesby ray tracing and percentage error method, and using the measured sound velocity profile data tovalidatethe algorithm.The results show that, by optimizing the threshold value for D-P algorithm, sound velocity profile data reduction rate can be 90% or more, standard deviation of percentagedepth is less than 0.1%, the optimized sound velocity profileshave important practical engineering application value that theycan significantly improve multi-beam survey and data processing efficiency.

An Adaptive Enhanced Lee Speckle Filter for Polarimetric SAR Image

2014, 43(7):  690-697. 

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The refined Lee filter, which is simple, efficient and robust, has been widely used in polarimetric SAR (PolSAR) processing. However, the filter has two severe defects: scallop effect and false-line effect. In this paper, we extend and improve the refined Lee filter by adding a square window and a group of linear windows. To better suppress the speckle noise as well as preserve the detail information, we adopt an adaptive window mechanism: big window is used in homogeneous areas and small window is used in heterogeneous areas. So the proposed filter can adapt actual scenes in both shape and size aspects. Both airborne and spaceborne PolSAR data are used to demonstrate its overall speckle filtering characteristics by comparing with other filters. The results show that the adaptive enhanced Lee filter has better performance in speckle suppressing and detail preserving than the refined Lee filter, and can preserve the polarimetric information very well.

A Solving Method for the Boresight Misalignment of Airborne IMU Based on Relative Orientation

2014, 43(7):  698-704. 

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The boresight misalignment of airborne Inertial Measure Unite (IMU) is introduced into relative orientation model of aerial stereo image pairs using the inherent relative geometric relationship between aerial images, and a novel method to solve the boresight misalignment of airborne IMU based on relative orientation is proposed. The mathematical models for solving the boresight misalignment of airborne IMU are derived in detail based on a single stereo model and multiple consecutive stereo models, respectively. Then, three sets of actual images obtained with IMU are tested. The empirical results show that the mathematical model established is correct and feasible, and the boresight misalignment could be solved using multiple consecutive stereo models constituted by more than three adjacent aerial images. The method proposed in this paper could avoid many problems brought about by setting calibration field and the other ground control conditions, and it is beneficial for direct and quick georeferencing when using aerial remote sensing equipment with airborne IMU.

A Narrow River Extraction Method Based on Linear Information Enhancement in TM image

2014, 43(7):  705-710. 

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Extraction of narrow rivers from TM images can be hardly achieved due to mixed-pixel effects. This paper presents an automatic approach for narrow river extraction by integrating multiple digital image processing techniques. Firstly, the threshold segmentation was applied on water-index images to separate from planar water bodies and narrow rivers. Secondly, a linear information enhancement algorithm is adopted to highlight river information and suppress other information. Thirdly, narrow rivers are extracted using dual-threshold line tracking method. Finally, three methods are selected to remove shadow, roads and other noises. Experimental results show the approach can effectively extract narrow rivers with the extraction rate higher than 82%, false alarm rate lower than 7%, extraction quality higher than 79%, and completeness higher than 90%, and avoid impact from multiple kinds of noise.

Auto-registration for Terrestrial Laser Scanning Multi-Stations Point Clouds with Bundle Block Adjustment Method

2014, 43(7):  711-716. 

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Terrestrial laser scanning (Terrestrial Laser Scanning), whether for a single closed surface, or for a wide range of open terrain mapping, through a limited field of view, different perspectives, different spatial resolution multi-station scanning to complete the form of the objector surface morphometry. Multi-stations point clouds in free coordinate system need to be incorporated into unified coordinate system or coordinate system specified in project and construction. According to aerotriangulation in photogrammetry ,we proposed a theory named Auto-orientation for Terrestrial Laser Scanning Multi-stations Point Clouds with Bundle Block Adjustment Method, which can make an auto-orientation for multi-scanning stations point clouds in whole surveying area.

The Eliminate Method of Image Matching Gross Error Based on Local Vector Binning

2014, 43(7):  717-723. 

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This paper proposes a eliminate method that can apply to the gross error in image matching. The whole process can be divided into three steps. First, the Systematic differences are offset. Then, Triangulated Irregular Network (TIN) of image matching points are constructed to get the partitioning local binning. Based on the normal distribution of the image matching gross error, vector descriptor is proposed in the statistics on the local binning. The Reasonable threshold is set for quickly elimination of gross error. The feasibility of the method is tested based on the experimental verification of multiple groups of data. This method has been successfully applied to processing system of satellite image and low-level image.

Twisty Road Tracking from Remote Sensing Imagery Using Improved Circular Projection Matching

2014, 43(7):  724-730. 

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Road extraction from Remote Sensing imagery attracted great attention and with great difficulty. Direction of twisty road (winding road in mountainous areas, etc.) changes seriously, and has poor geometry consistency. Variable road width or interferences, such as shadow and shelter, etc, increase the extraction difficulty. To solve this problem, this paper proposes a tracking method for twisty roads based on improved Circular Projection Matching algorithm. First, this paper proposes two improvements based on standard Circular Projection Matching, including: (1) Proposes the approximation parameter for circular projection vector as the circular projection similarity control; An optimal radius is proposed in order to reduce the calculation of the Circular Projection Matching with enough road characteristics matained. (2) Presents an interference correction algorithm, to a certain extent, overcome the matching problem between selected template and target object due to difference of lighting condition, image noise and other factors. Secondly, proposes a road tracking method based on above improved algorithm, and also proposes an adaptive template matching mechanism. The matched road targets are proper weighted, and are considered as part of the followed template. This mechanism makes the template flexible and less affected by the variations and interferences of roads. Finally, SPOT-5 and GeoEye-1 Remote Sensing image is used for experiment. The experiment result shows that the proposed road tracking method is direction-independent, which is applicable to the twisty road extraction. Road centerline extraction error is about 2~5m, and road extraction accuracy is higher than 80%.

Research on Systematic Errors Calibration of 3D Terrestrial Laser Scanner

2014, 43(7):  731-738. 

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On the basis of introduction to principle of terrestrial laser scanner (TLS), self-calibration method for systematic error determination of TLS was discussed and systematic error models were derived in detail. In order to test the correctness of error model, an experiment was conducted. Data obtained by Leica HDS3000 was used in experiment. First some data were used as control information to calculate instrumental systematic errors, and then others were used as check information to testify the correction effect of systematic errors. The Experiment results show, after correcting systematic errors, data accuracy obtained by HDS3000 improve a lot, which demonstrates the correctness of error model.

An UKF phase unwrapping algorithm with a pre-filtering procedure

2014, 43(7):  739-745. 

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Combining an unscented KALMAN filter (UKF) with a conventional path-following strategy and an omni-directional local phase slope estimator as well as a pre-filtering procedure, this paper presents a new phase unwrapping algorithm with a pre-filtering procedure to perform almost noise canceling and phase unwrapping at the same time. Results obtained with synthetic and real data validate the effectiveness of the proposed method.

Progressive SIFT Matching Algorithm for Multi-Source Optical Satellite Images

2014, 43(7):  746-752. 

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Considering the low matching rate of SIFT for multi-source optical satellite images, based on SIFT matching method, initial controlling points constrained by the relative scale and main orientation of SIFT features are extracted in this paper. Then, Delaunay triangulation is built by initial matching points. Local geometrical constraint model is built through point spreading. Finally, on the basis of the main orientation of features, minimum Euclidean distance criterion and local RANSAC algorithm, the matching of multi-source optical satellite images is progressively achieved with high accuracy. Compared with other matching algorithms, in the case of large scale and rotate images, the proposed algorithm has significant advantages in terms of matching amount and precision.

A Parallel Geographical Network VRP Algorithm Based on PC Clusters

2014, 43(7):  753-760. 

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In PC clusters, the memory in each compute node is limited and the communication is inefficient. To solve these problems, a novel parallel algorithm for geographical network VRP is proposed. The main contents are as follows. Firstly, a distributed storage mechanism is designed to avoid the low memory problem. Then, instead of sending the complete solution, synchronizing the transformation of the solution is used to reduce the quantity of communication and improve the efficiency. Finally, a parallel geographical network VRP algorithm is implemented by parallelizing the OD matrix computing and the tabu search procedure. Several experiments are conducted on a PC cluster using simulated traffic networks. The results show that: the computational results of the proposed algorithm are consistent with ArcGIS, and the average deviation is between 2.11% - 2.87%; the distributed storage mechanism reduces the memory usage in each process and enhances the robustness and scalability of the algorithm; the parallelizing of the algorithm improves the efficiency of solving VRP; the proposed algorithm has good parallel performance, and the speedup is between 4.46 - 6.32 in all test datasets using 8 processes.

Intelligent Road-network Selection using Cases Based Reasoning

2014, 43(7):  761-770. 

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The developing of intelligent automated generalization has been a challenging problem to be solved because of the complex thinking of human beings. A new approach of intelligent road-network selection using cases based reasoning (CBR) was put forward in this paper. In this approach, learning and cognition techniques of human being in artificial intelligence were used to establish, learn and reason the cases of cartographers. First, it took a certain area’s road-network selection result achieved from interactive selection of cartographic experts as reference templates, and transformed the templates into selection cases after establishing the description structure of cases. Second, the cases were analyzed and reasoned with enhanced simplifying and generalizing methods so as to get more effective case model base. Finally, the computer finished the similar road selection using CBR technique supported with the enhanced case model base. Compared with the past algorithms, the new approach uses enhanced road selection cases to simulate the thinking of human being, and CBR model to select similar road-work intelligently, which fetches up the shortcoming of intelligence of traditional road selection methods, and creates a new embranchment in the field of intelligent automated generalization. Examples and related analyzing and assessing results illustrate the scientificity and usability of the new approach. And further works to be improved are also suggested at the end of this paper.