SOFTWARE REVIEW Cartographic Visualization with

In the education, research and advisory services environment of our institute (ITC, the License Manager, but only one hardware key), ArcView has exactly the same func- Netherlands) we have come across quite a few wrong ideas of what ESRI's new ArcGIS tionality but is extended by ArcGIS in providing access to multi-user editing, really is about. ArcGIS is not simply another software package. On the contrary, it is a advanced analysis and spatial database and Internet services (the latter not only family of GIS software products with the same architecture and a common (Windows) for dissemination purposes, but also to access data in e.g. the Geography user interface. However, it has different "levels of functionality" which may be Network). ArcView 8.1 may be customized at different levels. It includes, for employed according to the specific GIS needs and requirements of the users and their instance, Visual Basic for Applications.

organizations. The big advantage is, of course, that users do not have to familiarize

themselves with new software and a new interface as soon as they need more func-

tionality. ESRI facilitates differences and possible changes in user needs by applying a

flexible and "floating" license concept with the installation of the ArcGIS desktop. ArcGIS Licensing

By Corne P.J.M. van Elzakker ArcEditor 8.1 is neither the same nor the successor of ArcEdit. It is a completely new maps, data and tools. It is software product with the same functionali- envisaged that users will ty as ArcView 8.1 but with the additional typically interact with the power to edit features in a multi-user geo- 40 system by having two or database or (ArcInfo) coverage. And next to all three of these applica- all this, ArcInfo 8.1 has more advanced tions active. ArcToolbox geo-processing functionalities, as expressed contains functionalities for by the maximum number of ArcToolbox data conversion and geo- functions referred to above. It should be processing by means of noted that ArcInfo 8.1 in fact consists of wizards. ArcMap is meant ArcInfo Desktop, with only menus and wiz- for the basic editing, ards, as well as the complete "old" ArcInfo querying, analysis and Workstation, with the same interface as integration of geo-data, ArcInfo 7. usually involving data dis- play and cartographic visualization. Finally, ArcGIS Extensions The ArcGIS Family ArcCatalog is the applica- In fact, there are three increasing levels of tion for the browsing, management, cre- There are six new ArcGIS extensions that add functionality, combined in the desktop soft- ation, organization and maintenance of functionality to ArcView, ArcEditor or ArcInfo. ware products ArcView, ArcEditor and geo-data and their metadata. Functionally wise, these extensions do not ArcInfo successively. Users may decide to differ when called upon by either ArcView or install one of these products, depending ArcEditor or ArcInfo. The Spatial Analyst on their needs and the available license. ArcView, ArcEditor and ArcInfo extension combines the capabilities of the All three are based on a combination of extension we already knew of the former the standard applications ArcMap, The new version 8.1 of ArcView forms the versions of ArcView with those of ArcGRID. ArcCatalog and ArcToolbox with, as men- basis of ArcGIS and possesses standard The extension can be used for surface cre- tioned before, more or less functionalities. GIS functionalities. It is the only product ation, raster analysis and grid algebra. 3D For instance, whereas ArcToolbox has only of the ArcGIS 8.1 family that is also mar- Analyst is for 3D visualization and analysis 20 functions in ArcView and in ArcEditor, it keted in some countries as a stand-alone and combines the capabilities of the old 3D has more than 170 functions in ArcInfo. The GIS (single-user license with a separate Analyst extension of ArcView and ArcTIN. 3D ESRI idea behind the three different appli- "dongle" (=hardware key)). In the con- Analyst includes the new three-dimensional cations ArcMap, ArcCatalog and ArcToolbox current use license version (the only viewing application ArcScene. Geostatistical is that they represent the fundamental license that is available for ArcEditor and Analyst is a new extension for advanced sur- methods of how people interact with a GIS: ArcInfo, requiring the installation of the face interpolation, modelling and exploratory

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is not possible any longer to reverse this action. Therefore, users have to take great ESRI'sESRI's ArcGISArcGIS 8.18.1 care when organizing files in GIS folders.

spatial data analysis. The new ArcPress cessor. Therefore, we will not deal any fur- Cartographic Digitizing and extension is a PostScript-based Raster Image ther with the working of ArcToolbox, nor with Editing in ArcMap Processor (RIP) for printing and exporting of many other standard GIS functionalities and maps with improved colour output control. the new 'geo-database' object-oriented vec- In ArcMap, new cartographic features may StreetMap is for street display and geo-cod- tor data model that increases interoperability. be created and existing ones edited, similar ing (at the moment, for the USA only) and Instead, we will concentrate on the carto- to ArcView 3.x but with many new function- the MrSID Encoder produces smaller-sized graphic functionalities of ArcMap. But, before alities. Users need no longer be dependent MrSID images from geo-referenced input doing so, first a few words should be devot- on buying cartographic datasets but may images up to 500 MB and mosaics MrSID ed to ArcCatalog. For ArcCatalog is a very create or edit their own. Input of various images. Other new ArcGIS extensions are on useful management tool to connect to data data formats is possible, or use can be their way (e.g. Survey Analyst, Network sources (be they e.g. on the local hard disk, made of digitizing tablets that support the Analyst, Tracking Analyst, Business Analyst, on the Intranet or the Internet) and to pre- Wintab driver. Compared to the possibilities Maplex, etc.). Finally, ArcSDE and ArcIMS are offered by ArcView 3.x, the new snapping the fully integrated application services on interface and facilities make digitizing more the ArcGIS platform. ArcIMS adds Inter- and ArcView and ArcMap in comfortable. Examples are vector snapping Intranet functionality to ArcGIS and ArcSDE is capabilities like snapping to reference layers the interface for storage and management of version 8.1 definitely are among with different priorities and selecting snap- a multi-user geo-database in a DBMS. ping types like: snapping to vertices, edges Together, these application services make the best software solutions for or the end of a line. Placing functionalities possible a mutual integration of Internet, are extended with construction tools like Intranet and local geo-data and also allow creating various thematic map placing vertices at intersections of two dis- for their dissemination. tances from two other points, or at the types in a GIS environment. implied intersection of two segments. Lines can be placed at different angles, distances System Requirements or deflections and parallel or perpendicular view the data. It is more than just the to other segments. For on-screen digitizing 41 The ArcGIS desktop products run on 'Windows Explorer' of ArcGIS, if only raster images may be geo-referenced in Windows NT4 (SP 6a or higher), Windows because of the options to incorporate and ArcMap. First, second and third order trans- 2000 (SP1) and Windows XP. The minimum edit meta data. In addition, ArcCatalog does formations are supported, but it is a pity system requirements are a Pentium 450 MHz not only provide cartographic and tabular that raster tracing is not. However, segments with 128 MB RAM, but a Pentium 650 MHz previews of the data, but also offers some may be traced, with or without offset. To or higher with 256 MB RAM (available) and basic functionality to explore, query and edit maintain relationships while editing a more than 1 GB disk space (without data) is the data on the basis of these previews. For dataset with different layers in which fea- strongly recommended (and perhaps even example, in the map preview it is possible to tures share common boundaries or points, necessary, as we have discovered). These "identify" singular objects in a similar way there is a possibility to snap to vertices, requirements are one of the reasons why as in ArcView 3.x. Furthermore, the user may edges or endpoints of features that are situ- ESRI will continue the support of ArcView edit a table preview by adding or deleting ated in other layers than the current editing 3.x for the time being. After all, for running fields. A disadvantage is that the user is not layer. In ArcMap, features from different data ArcView 3.x all you need is a Pentium with able to add or change values for a field. sources that share common boundaries or 32 MB and Windows 95/98. Besides, the Another functionality is the calculation of points may now also be integrated, using a stand-alone version of ArcView 8.1 is some- statistics and the production of a frequency specific function. what more expensive than ArcView 3.x, and distribution for a field. ArcCatalog another reason why users may want to con- also offers useful search functionali- tinue working with 3.x is that a customiza- ty: a user may search by geographic tion with Avenue scripts cannot be trans- location and within the metadata. ferred to the 8.1 environment. Searching based on geographic location is possible by drawing a box around the area of interest, by ArcCatalog selecting a location from a drop- down list, by specifying geographic In view of the expertise of the authors, the coordinates in text boxes or starting rest of this concise review of comprehensive from a user-defined map. One software will emphasize the cartographic important thing that is missing in visualization aspects of the ArcGIS desktop the main menu of ArcCatalog is an applications, usually in comparison with "undo" function. For example, after Thumbnail views in ArcCatalog of the data in a database. From ArcView 3.x, the most "cartographic" prede- deleting a file in the catalog tree it ArcCatalog, ArcMap may be launched directly.

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Projections and Coordinate the raster image. If there is Transformations not enough coordinate informa- tion one can add the missing Whereas in ArcView 3.x the emphasis information, or, in the case of was on the map projection, in ArcGIS the a raster, one can supply a set emphasis is on the coordinate system. of control points and link the The map projection is just one compo- raster image to the map coor- nent in a layer's coordinate system. dinates of the data frame by ArcGIS supports a huge number of coor- means of a two-dimensional dinate systems: around 1500 internation- correction model. Supported al, continental and national map coordi- models are linear equations, nate systems and more than 300 and second and third order The ArcMap interface with a new way to show quantities: Proportional Symbols. different datum systems have been polynomial equations. defined. In ArcView 3.x a shapefile may Orthophoto correction models are not done in layout view that now allows only be displayed in different projections supported. There is a raster resampling (unlike ArcView 3.x) interaction with the as long as the source shapefile is capability to permanently re-project the data as well. defined as geographic (or unprojected) raster image. In ArcMap, features in layers may be sym- with units set to decimal degrees. If you bolized with the help of many standard want to display a projected shape file in symbol sets that are directly accessible. a different projection, first you must per- New Possibilities for Cartographic Regrettably, the symbols are arranged manently change the projection by creat- Visualization in ArcMap according to map themes ("transportation", ing a new shape file using the Projection "weather", etc.) and not according to the Cartographic visualization in a visual variables applied. The latter would GIS environment need not help a user to also select effective symbols always be directed towards the in other application areas. However, there production of maps for presenta- are more and more user-friendly possibili- tion. Such a GIS environment ties now to design new symbols (e.g. in may also allow for direct explo- the 'Symbol Property Editor'). The symbols ration and analysis of the geo- designed may also be stored in a symbol data through map and other library (called 'Style' in ArcMap) for use in 42 graphic displays. In this respect, later map displays. dynamics, multiple representa- tion, dynamic linking and interac- In addition to the 'Legend types' of tion with maps are among the ArcView 3.x, ArcMap offers some new stan- key concepts . Some new possi- dard thematic map types and ways to bilities for exploratory and ana- adjust them. There is, for instance, a new Part of the Symbol Property Editor window, which may be used to lytical visualization may be found option ('Unique values, many fields') to make tailor-made symbols by trial and error. in the ArcGIS extensions 3D represent more than one nominal data field Analyst and Geostatistical Analyst in the attribute table at the same time (by Utility extension. However, this utility is in particular. But it is also very well possi- e.g. colour with a pattern overlay). Also, rather slow and only supports a limited ble to interact with map displays in various there is more variation possible in the number of coordinate systems. Therefore, ways in the standard ArcMap environment. application of the map type 'Chart': pie it is good that in ArcMap it is possible As before, it is possible to pan and zoom, graphs and bar graphs may take on differ- to re-project already projected data to click map features to get more detailed ent shapes and a third type of chart, the directly ("on-the-fly"), whereby data can information and to experiment with e.g. 'stacked' bar graph, has been added. And be in any coordinate system. For existing ways of representation and dif- shapefiles you will need to define a pro- ferent data classifications. One jection file using ArcCatalog or interesting new interaction possi- ArcToolbox so that ArcMap knows the bility is to rotate the whole map projection of your data. Furthermore, image (leaving the map text in while in ArcView 3.x the Warp extension the correct, horizontal position). can be used to geo-reference grids, Within a 'Map document' (the ArcMap offers a similar function that is ArcGIS concept that replaces the faster, more user-friendly and more ArcView 3.x 'Project') it is not extensive. If there is enough coordinate possible anymore to have more system information, layers in an ArcMap than one 'Data frame' (cf. 'View' data frame are aligned by an on-the-fly in 3.x) open at the same time, re-projection of both vector and raster so as to be able to compare dif- layers. In such a way a raster may be ferent visualizations in data view The Symbology tab in the Layer Properties dialog window (accessible combined with several vector layers in directly. This comparison of mul- by right-clicking the layer in the Table of Contents) has replaced one map without the need of resampling tiple representations must be ArcView 3.x's Legend Editor.

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there are two ways now of generating pro- possible in ArcView 3.x. You now have tially lead to obtaining a better insight into portional point symbol maps: 'Graduated many more options for defining how you and overview of these data. At the same symbols' (with the data automatically want your labels to appear in the map. time, however, this great flexibility may grouped into classes) and 'Proportional ArcMap offers somewhat better and more result into wrong interpretations as a con- symbols' (as many symbol sizes as there default colour schemes for the representa- sequence of the fact that existing carto- are data values). tion of nominal, categorical data and better graphic knowledge is not yet optimally default graded series for the representation applied and that users (who may want Although this increased variation in stan- of relative quantitative ('normalized'), inter- this) are not yet always properly guided dard thematic mapping methods may be val or ordinal data. The default graded through the cartographic visualization pro- considered an improvement, there are still series in ArcView 3.x, for instance, always cess. It is hoped that more cartographic a number of minor cartographic objections contained colours that were too dominant user guidance and an appropriate imple- against the ways these map types are con- and thus created a wrong impression. But mentation of even more already existing structed by default. For instance, in propor- still, the flexibility in colour selection cartographic knowledge will be considered tional symbol maps, the maximum value in offered by ArcMap may also often lead to in new releases, so that this may lead to a the legend does not correspond to the problems and it would be desirable to offer more effective use of GIS through carto- maximum data value and polygons with an the colours to the users in ways, which are graphic and other visualizations. excluded data value (e.g. 0) are not drawn more directly related to the purpose of the anymore. But the individual symbol sizes map displays (e.g. by means of Ostwald are correctly proportional now to the data colour circles). In ArcMap, standard colours Corné P.J.M. van Elzakker ([email protected]) values. As in ArcView 3.x this is still not are defined as RGB-values. In case printed (with contributions from Nicoline N.M. Emmer, the case in the graduated symbol maps: map output is desired, colour definition in Richard A. Knippers and Willy J. Kock) there, the symbol sizes are not proportion- the CMYK-system is supported as well with Division of Geoinformatics, Cartography and al to the mid-class data values because possible export to PostScript colour sepa- Visualization, International Institute for Aerospace ArcMap offers a default symbol size for rates. Presentation maps with titles, leg- Survey and Earth Sciences (ITC), Enschede, The both the minimum and the maximum value end, scale bars, etc. may still be made in Netherlands. the 'layout view', e.g. on the basis of vari- ous map templates. Next to formats as BMP, EPS, TIFF, PDF, JPG, CGM, an ArcMap 43 layout view can also be exported to a vec- tor file (in "Enhanced Meta Format") that may be edited in a graphic design soft- ware package. This makes it possible, for instance, to move individual features in An interactive histogram may be used to set the class limits. the map in order to improve its legibility at the same time, irrespective of the data without disturbing the geographical data range. A real improvement with respect to structure that forms the basis of ArcGIS. the representation of quantitative data (also by means of 'Graduated colors', i.e. choropleth maps) is the provision of a Conclusion visual tool (a histogram of the data) to be used in interactive data classification. ArcView 3.x and ArcMap in version 8.1 def- Interesting new cartographic design options initely are among the best software solu- that are offered by ArcMap are the direct tions for creating various thematic map availability of an overview/location map, an types in a GIS environment. Since the ini- interactive moving magnifying glass that tial release of ArcView 1.0, we have seen allows you to zoom into parts of the map that more and better cartographic function- display, whereas the surroundings remain ality has been added to the successive represented at the same scale, and the software products. And also ArcGIS is now possibility to make a layer transparent. offering to the user many new and useful Also the labelling functions (automatic tools for the interactive cartographic visual- name placement and map text design) are ization of geographic data. The increased really improved compared to what was flexibility in using these tools may poten-

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