Statistics for Spatial Data.

On robust estimation of the location parameter

Computer and Robot Vision Vol. 1, by R.M. Haralick and Linda G. Shapiro, Addison-Wesley, 1992, ISBN 0-201-10887-1.

Computer and Robot Vision

Semiology of Graphics: Diagrams Networks Maps.

Because of sensor malfunction and poor atmospheric conditions, there is usually a great deal of missing information in optical remote sensing data, which reduces the usage rate and hinders the follow-up interpretation. In the past decades, missing information reconstruction of remote sensing data has become an active research field, and a large number of algorithms have been developed. However, to the best of our knowledge, there has not, to date, been a study that has been aimed at expatiating and summarizing the current situation. This is therefore our motivation in this review. This paper provides an introduction to the principles and theories of missing information reconstruction of remote sensing data. We classify the established and emerging algorithms into four main categories, followed by a comprehensive comparison of them from both experimental and theoretical perspectives. This paper also predicts the promising future research directions.

Missing Information Reconstruction of Remote Sensing Data: A Technical Review

In the representation of topographic data, the distribution of hydrographic networks should be constrained by the contour model’s landform features. During the integration of topographic databases, however, spatial conflicts may destroy these constraints, generating inconsistencies. This study presents a method to detect and correct inconsistencies between river networks and contour data by spatial knowledge. First, structured terrain features are extracted from the contour-based geometric representation and matching relationships between rivers and contours are constructed based on spatial knowledge of the distribution of rivers and talwegs. We then propose a distance metric for measuring differences and identifying inconsistencies between the matched river and contour features. Three correction approaches are provided for different inconsistency situations, including river adjustment referenced to the contour, contour adjustment referenced to the river and adjustment of both river and contour to middle ...

Detection and correction of inconsistencies between river networks and contour data by spatial constraint knowledge

A recognition method for drainage patterns using a graph convolutional network

The potential vegetation index determined by environmental conditions especially climate is the ideal baseline for assessing vegetation degradation based on remote sensing. After eliminating irrigated areas. This paper estimated the potential vegetation index by imitating upper borderline of scatter spots in the coordinates space of climate aridity index and remote sensing vegetation index. Then we assessed the vegetation degradation through comparing actual vegetation index with potential vegetation index. The climate aridity index is expressed by the ratio of Holdridge's potential evapotranspiration and precipitation. The average value of SPOT VGT NDVI on July to September for many years is choosed as the vegetation index. As a result, potential vegetation index tends to saturation when aridity index is below 0.8. When aridity index is over 0.8, we can simulate potential vegetation index by a general index function. The degree of vegetation degradation takes on prominent spatial difference. On the whole, it is the most severe in the middle and the east of Gansu province and the south of Ningxia autonomous region.

Assessing vegetation degradation in Loess Plateau by using potential vegetation index

Automatic generation of multi-scale representations from the same spatial data source has been the research focus in map generalization for a long time. Based on the Fourier technique, this paper p...

Fourier-based multi-scale representation and progressive transmission of cartographic curves on the internet

This article presents an area-preservation approach for polygonal boundary simplification by the use of structured total least squares adjustment with constraints (STLSC), with the aim being to maintain the area of the original polygons after the simplification. Traditionally, a simplified line is represented by criti- cal points selected from the original one. However, this study focuses on maintaining the areas of the polygons in the process of simplification of polygonal boundaries. Therefore, the proposed method in this article is a supplement to the existing line simplification methods, and it improves the quality of the sim- plification of polygonal boundaries in terms of positional and area errors. Based on the sub-divisions of the original polyline, using the critical points detected from the polyline by the use of line simplification methods, the framework of the proposed method includes three main components, as follows: (1) estab- lishment of the straight-line-segment fitting model based on both the critical and intermediate points on the sub-polyline; (2) introduction of both area and end-point constraints to reduce the geometric distor- tions due to the line simplification; and (3) derivation of the solution of boundary simplification by the use of STLSC. An empirical example was conducted to test the applicability of the proposed method. The results showed that: (1) by imposing the linear fitting model on both the critical and intermediate points on the sub-polylines in the proposed STLSC method, the positional differences between the original points and the simplified line are approximately in a normal distribution; and (2) by introducing both end-point and area constraints in the proposed STLSC method, the areas of the simplified polygons are the same as those of the original ones at different scales, and the two neighboring fitted lines are connected to each other at the optimized position.

Tinghua Ai

Papers

Detection and correction of inconsistencies between river networks and contour data by spatial constraint knowledge

A recognition method for drainage patterns using a graph convolutional network

Assessing vegetation degradation in Loess Plateau by using potential vegetation index

Fourier-based multi-scale representation and progressive transmission of cartographic curves on the internet

Area‐preservation Simplification of Polygonal Boundaries by the Use of the Structured Total Least Squares Method with Constraints