The use of digital map data in the segmentation and classification of remotely-sensed images

Abstract

Remotely-sensed data constitute a major potential source of input to geographical information systems (GIS)However, these data often have a relatively poor classification accuracy compared with that of the cartographic data from maps with which they may be combined in the course of GIS analysis. The possibility exists of using data sets (in the form of digital maps) resident within a GIS in order to improve this accuracy, before the classified image is incorporated into the GIS. Results are discussed from a British Alvey Information Technology project to develop a system for the knowledge-based segmentation and classification of remotely-sensed terrain images, in which the knowledge contained in digital map     

The establishment and application of the geographic mapping database by city/county unit in China

Abstract

Based on information contained in the third population census and the second industrial investigation, and illustrated by maps, this paper discusses the conceptual design, methodology and procedures used in the establishment and application or the geographic mapping database. The statistical cartographic expert system is specifically introduced as an application.     

Monitoring grasshopper and locust habitats in Sahelian Africa using GIS and remote sensing technology†

Abstract

Development programmes in Sahelian Africa are beginning to use geographic information system (GIS) technology. One of the GIS and remote sensing programmes introduced to the region in the late 1980s was the use of seasonal vegetation maps made from satellite data to support grasshopper and locust control. Following serious outbreaks of these pests in 1987, the programme addressed a critical need, by national and international crop protection organizations, to monitor site-specific dynamic vegetation conditions associated with grasshopper and locust breeding. The primary products used in assessing vegetation conditions were vegetation index (greenness) image maps derived from National Oceanic and Atmospheric Administration satellite imagery. Vegetation index data were integrated in a GIS with digital cartographic data of individual Sahelian countries. These near-real-time image maps were used regularly in 10 countries for locating potential grasshopper and locust habitats. The programme to monitor vegetation conditions is currently being institutionalized in the Sahel.     

Stereoscopic Images From Isoline Maps

Abstract

Beginning students of geography often have difficulty understanding contour and other isoline maps. If the contours can be seen in three dimensions, this concept of surface representation is grasped much more readily. The simplest way for an instructor to demonstrate the isoline concept is to draw stereopair contour images, which, when viewed through a stereoscope, show a three-dimensional surface. Crude, but effective stereocontour maps can be drawn by anyone, regardless of cartographic skill, by using the method outlined in this paper.     

Improvement of GIS graphics for analysis and decision-making

Abstract

Current geographical information systems (GIS) include functions to create cartographic output interactively or automatically. However, none of the systems presently incorporates mechanisms to ensure correct application of graphic functions. Many of today's users of GIS are not trained in the design and production of graphics and may create maps that confuse or mislead map users. Poorly-designed maps may obliterate the patterns in displayed information.

This article investigates ways to improve the quality of GIS graphical displays and increase their effectiveness for decision-making. Alternatives are presented for improving map design in GIS, ranging from non-technical efforts to enhancement of software functionality. Suggestions propose augmenting users' abilities to create maps in an automated environment, using an approach termed amplified intelligence: key decisions default explicitly to users, whose knowledge is amplified by a range of high-level tools to carry out map design operations automatically.     

Evaluating the impact of visualization of risk upon emergency route-planning

ABSTRACT

This paper reports on a controlled experiment evaluating how different cartographic representations of risk affect participants’ performance on a complex spatial decision task: route planning. The specific experimental scenario used is oriented towards emergency route-planning during flood response. The experiment compared six common abstract and metaphorical graphical symbolizations of risk. The results indicate a pattern of less-preferred graphical symbolizations associated with slower responses and lower-risk route choices. One mechanism that might explain these observed relationships would be that more complex and effortful maps promote closer attention paid by participants and lower levels of risk taking. Such user considerations have important implications for the design of maps and mapping interfaces for emergency planning and response. The data also highlights the importance of the ‘right decision, wrong outcome problem’ inherent in decision-making under uncertainty: in individual instances, more risky decisions do not always lead to worse outcomes.     

Beyond Abstract Map Symbols

Abstract

Crucial aspects of the referent phenomena which provide the subject matter for cartographic symbolism are often overlooked by map interpreters in their haste to “read maps at a glance.” The blame rests largely on those practitioners of the environmental sciences who stress the simple, intuitive nature of maps, while effectively ignoring the true complexity of the cartographic communication process. Those persons who are responsible for traditional map interpretation training programs are also at fault for implying, through long emphasis, that symbol identification, position location, and navigation constitute the essence of map analysis. The intuitive acceptability of map symbols in spite of their abstract character is also a deceptive factor. The fact that there is far “more than meets the eye” to map interpretation is easily demonstrated by looking closely at several basic cartographic symbols. In order to become an effective map user the environmental scientist apparently must go well beyond the mastery of conventional map reading principles and learn to deal with diverse informational dimensions in the context of the map use purpose and the physical/cultural make-up of the geographical region under study.     

School Students' Understanding of Choropleth Maps: Evidence From Collaborative Mapmaking Using GIS

Abstract

Pairs of students from two age groups made choropleth maps using Arc View. Evidence from their discourse is used to assess aspects of their cartographic understanding as well as the nature of their collaboration. Students from both age groups spent a high percentage of their time talking about cartographic strategy and a low percentage of time on technical aspects of GIS functionality. Older students engaged in more reasoning and questioning. Key areas for teacher intervention include promoting better student understanding of what the mapped data mean (including directionality and numerical characteristics) and the most effective strategies for raising the level of students' conceptual exchange during collaborative learning.     

Fundamental operations in computer-assisted map analysis

Abstract

Geographical information systems (GIS) provide capabilities for the mapping, management and analysis of cartographic information. Unlike most other disciplines, GIS technology was born from specialized applications. A comprehensive theory relating the various techniques used in these applications is only now emerging. By organizing the set of analytic methods into a mathematical structure, a generalized framework for cartographic modelling is developed. Within this framework, users logically order primitive operators on map variables in a manner analogous to traditional algebra and statistics. This paper describes the fundamental classes of operations used in computer-assisted map analysis. Several of the procedures are demonstrated using a fourth-generation computer language for personal computers.     

Historical-geographical mapping of the Baikal region

The structure of the block of retrospective maps of ecological contents has been developed for the digital Atlas of sustainable development of the Baikal region. Presented are the methods for reconciliation and integration of different-time interdisciplinary geographical information, originating from different archival sources, into a unified cartographic system.     

Automatic extraction of road intersection points from USGS historical map series using deep convolutional neural networks

ABSTRACT

Road intersection data have been used across a range of geospatial analyses. However, many datasets dating from before the advent of GIS are only available as historical printed maps. To be analyzed by GIS software, they need to be scanned and transformed into a usable (vector-based) format. Because the number of scanned historical maps is voluminous, automated methods of digitization and transformation are needed. Frequently, these processes are based on computer vision algorithms. However, the key challenges to this are (1) the low conversion accuracy for low quality and visually complex maps, and (2) the selection of optimal parameters. In this paper, we used a region-based deep convolutional neural network-based framework (RCNN) for object detection, in order to automatically identify road intersections in historical maps of several cities in the United States of America. We found that the RCNN approach is more accurate than traditional computer vision algorithms for double-line cartographic representation of the roads, though its accuracy does not surpass all traditional methods used for single-line symbols. The results suggest that the number of errors in the outputs is sensitive to complexity and blurriness of the maps, and to the number of distinct red-green-blue (RGB) combinations within them.     

Geographic information systems and the BBC's Domesday interactive videodisk

Abstract

The Domesday Project is an ambitious attempt by BBC Enterprises Ltd to present a contemporary snapshot of the United Kingdom in the 1980s on interactive video disk. Two disks are being produced: the first, the local or community disk, consists essentially of information collected by the British people. The second, the national disk, has (amongst other material) a selection of data from both government and quasi-government sources. In total, the disks will hold about 250 Mb vies of digital data. ;is well as some 50000 photographs and around 20 million words of text. The paper introduces the idea of interactive video and the local disk. It then concentrates on methods of access to, and cartographic display of, data on the national disk. We conclude that it is a significant geographical information system which will ultimately form one of the most widely-used data base systems for the foreseeable future.     

Quadtree storage of vector data†

Abstract

Vector data storage has various advantages in a cartographic or geographical information system (GIS) environment, but lacks internal spatial relationships between individual features. Quadtree structures have been extensively used to store and access raster data. This paper shows how quadtree methods may be adapted for use in spatially indexing vector data. It demonstrates that a vector quadtree stored in floating point representation overcomes the classical problem with raster quadtrees of data approximation. Examples of vector quadtrees applied to realistic size data sets are given     

Object-oriented knowledge-based symbol selection for visualizing statistical information

Abstract

Object-oriented schemes for representing and processing knowledge concerned with cartographic sy mbolization in GIS have been suggested by a number of researchers. As a sequel to these research efforts, the problem of object-oriented knowledge representation in the domain of symbol selection for visualizing spatial statistical information is addressed in this paper, and an operational system on this domain is presented. First, the domain knowledge is specified, and the decision process for symbol selection is formulated. Then the specified knowledge is represented and processed in an object-oriented manner. Implementation issues are discussed, and results are demonstrated with examples.     

Map Reading and Abuse

Abstract

The various advantages and limitations of geographical mapping known to map users can be functionally related to the few basic principles which constitute the very nature of the cartographic technique. Numerous map interpretation errors may be traced in large part to a common failure on the part of map users to grasp and effectively deal with these same mapping principles. Since it is possible to identify situations in environmental decision making and planning where the misuse of maps, or outright map reading abuses, could lead to adverse human and environmental impact, the problem is indeed serious. Strategies for minimizing the misuse or abuse of geographical maps appear to rely most heavily on a thorough understanding of basic mapping principles.     

Road network simplification with knowledge-based spatial analysis

A typical requirement in digital society is the rapid distribution and effective application of digital products. Geographical data bases are far more complex than other ones in that both attribute and spatial data have to be stored and handled under the same framework. On the other hand, the number of end users of digital cartographic data is explosively increasing, ranging from professional map makers to vehicle drivers and individual tourists. Thus arises a question: how can a data supplier give the “best” service to each user? In nature it involves such difficult problems as cartographic generalization and map simplification. In this paper, the author argues that the visual knowledge or perception experience can be effectively exploited and used to guide the process of data simplification. We have developed a prototype system with a subset of the vector road database covering Munich city.

     

Paper versus Pixel: Effectiveness of Paper versus Electronic Maps To Teach Map Reading Skills in an Introductory Physical Geography Course

Abstract

This article addresses the lack of outcome-based research on the integration of technology into pedagogy at the undergraduate college level. It describes a study performed at a Midwestern university, testing the relative effectiveness of paper and electronic topographic maps for teaching map-reading skills, and considers the relationship between learning styles and paper or digital map preference. Results indicate that, although student map skill performance did not differ significantly with the use of paper or electronic maps, students preferred paper maps. Neither their performance nor their preferences were related to learning style. The article discusses the significance of these findings.     

Coordinating hazardous waste management activities using geographical information systems

Abstract

This paper describes a framework for the role of geographical information systems (GIS) in the monitoring and management of hazardous waste sites. Compilation of required information, incorporation of existing strategies for waste monitoring, analysis of these data in a GIS environment and the integration of computerized models for transport processes are discussed. Examples for the analysis of spatial data using techniques of cartographic overlay and the implementation of geo-statistical methods on monitoring data are provided from work in progress by the authors. These examples are set in the context of developing a fully integrated monitoring and management system utilizing GIS technology.     

Automatic alignment of contemporary vector data and georeferenced historical maps using reinforcement learning

ABSTRACT

With large amounts of digital map archives becoming available, automatically extracting information from scanned historical maps is needed for many domains that require long-term historical geographic data. Convolutional Neural Networks (CNN) are powerful techniques that can be used for extracting locations of geographic features from scanned maps if sufficient representative training data are available. Existing spatial data can provide the approximate locations of corresponding geographic features in historical maps and thus be useful to annotate training data automatically. However, the feature representations, publication date, production scales, and spatial reference systems of contemporary vector data are typically very different from those of historical maps. Hence, such auxiliary data cannot be directly used for annotation of the precise locations of the features of interest in the scanned historical maps. This research introduces an automatic vector-to-raster alignment algorithm based on reinforcement learning to annotate precise locations of geographic features on scanned maps. This paper models the alignment problem using the reinforcement learning framework, which enables informed, efficient searches for matching features without pre-processing steps, such as extracting specific feature signatures (e.g. road intersections). The experimental results show that our algorithm can be applied to various features (roads, water lines, and railroads) and achieve high accuracy.     

Research related to geographical information systems at the Natural Environment Research Council's Unit for Thematic Information Systems

Abstract

The wide variety of research into aspects of geographical information systems (GIS) undertaken at the Natural Environment Research Council's Unit for Thematic Information Systems is described. This includes work on spatial data models, on the application of artificial intelligence to improve the quality of input of remotely-sensed data, on automation of map cataloguing, on improving display and on GIS modelling.