Spatial Technologies30 Sep, 2004 By: James L. Sipes Cadalyst
Producing Maps with GIS: GIS takes the pain out of map-making.
Mapping is the visual representation of data, and one of the best ways to link information to a place. Maps may show what everyone expects, or they may reveal patterns and trends in data that are impossible to see any other way. Traditionally, cartographers, geographers, surveyors, planners, and other professionals have created maps, and the process was slow and meticulous. It could literally take months, or even years, to produce high-quality paper maps. Today, GIS programs have made it easier than ever to quickly and affordably generate maps for virtually any project.
The fundamental idea behind GIS programs is to create maps, so it should come as no surprise that most of them do it very well. By linking datasets to geographic locations and features, GIS makes it possible to graphically and spatially visualize complex data. Most of this visualization is in the form of thematic maps that visually represent the geographic distribution of data such as population trends, statistical data, ecological diversity, and other types of spatial information. Thematic maps have a variety of uses, including community planning, utility planning and management, emergency response, habitat restoration and enhancement, watershed planning, coastal planning, economic development, and impact assessment, just to name a few.
Figure 1. A group of landscape architects, headed by Design Workshop, worked with the Nevada Department of Transportation to explore different ways to implement landscape and aesthetic guidelines for all of the major transportation routes within the state.
Conservation groups and local governments are also starting to use GIS mapping as a way to get citizens involved in the planning process. A community map depicts, at a minimum, where a community wants to encourage growth, the character of desirable growth, and where growth should be deferred. The nice thing about generating maps is that citizens can physically see the results of their input.
Produce MapsOnce you create a GIS map, you must find a way to share this information with others. Online mapping is increasing in popularity because the information is so easy to access and modify. Some of the more complex computer-generated mapping programs are interactive, meaning that you can explore alternatives and ask what-if questions in real time as part of a public meeting. Another advantage of using the Internet is that maps can be developed by anyone with Internet access.
Despite the advantages of online mapping, there's something reassuring about paper maps. You can touch them, draw on them with markers, and roll them up and take them home with you. One big advantage of paper maps over online maps is that you can see the entire map at once.
Software for Map MakingGIS packages vary considerably, from those capable of displaying simple maps from geospatial data to more complex GIS programs that have more advanced relational database and mapping capabilities. Most of the top GIS programs have tools for creating and printing high-quality maps. Some of these tools are built into the program, some are extensions that expand the program's capabilities, and some are stand-alone programs that address specific needs.
Figure 2. All maps for the Nevada Landscape & Aesthetics Plan were posted on the Internet as PDF files, published in an 11" X 17" booklet, and printed in a poster format for presentation at public meetings.
ESRI's ArcGIS, for example, is an integrated collection of products for building a complete GIS. It provides a large array of symbols and cartographic capabilities for creating high-quality maps. To print a hardcopy of your map, there is ArcPress for ArcGIS, a print rasterizer for fast and high-quality printing and exporting. ArcPress processes a map on your computer and then transforms the map into the native language format of whatever printer you're using. This process reduces printing time and eliminates the need for extra memory or processors within the printer. ArcPress integrates with ArcGIS so printing is as simple as selecting an icon. Anybody who uses ArcGIS can benefit from ArcPress, especially if you produce large-format maps that contain high-resolution images or detailed vector data. As you rasterize an image, you can continue to work on other tasks, paper is automatically rotated to suit your image, and resolution is adjusted to best fit the selected printer or plotter.
ESRI also developed Maplex, high-end cartographic design software for creating quality labeling and annotation text for GIS maps. Anyone who has tried to create high-quality maps in ArcGIS will appreciate how Maplex simplifies the process. For example, one of the most time-consuming aspects of map production is name placement. Maplex automates the process by resolving conflicts between placements. The result is that names don't overlap and are located precisely where they need to be. The size and type style are consistent for all labels. User-specified placement rules let you control the final look of your map.
These rules can govern the priority of names, automatic name deletion, label offset, stacking, automatic font reduction, curving, abbreviation, and truncation of labels. With Maplex, you can use symbols that come with the program and import symbols from other sources, then modify all as needed.
Figure 3. With ESRIs ArcGIS 9.0, the department of transportation analyzed and synthesized base data to determine the potential locations in Las Vegas for amenities such as pedestrian linkages, rest areas, highway art, and environmental resource preservation.
Intergraph's GeoMedia is another powerful GIS program that provides a full suite of geospatial tools. GeoMedia includes layout composition tools that give you the flexibility to customize maps to meet specific needs. Tools are not only easy to use to create a basic map, but also powerful enough to create the highest quality maps possible. Enhanced layout composition tools in the latest version of GeoMedia provide control over features such as legends, scale bars, north arrows, grids, and symbols. New tools for editing layout graphics on the page include nudge, align, distribute, spin, and scale. Index grid generation is a new feature that places a grid over an area that can be used to determine the location of specific features.
Intergraph Map Publisher is part of a cartographic output system that consists of data collection, preparation, and rasterization software, and hardcopy and film plotters. Vector files are rasterized and composited in Map Publisher. You can define map colors, print priorities, masking, other characteristics of lithographic map design, and cartographic screen rulings, angles, and percentages. Map Publisher includes quality-assurance capabilities—you can preview or plot a raster image of the final map on a color or black and white plotter.
Bentley's GeoGraphics is an extension that adds database and geospatial functionality to the CAD features of MicroStation. This integration of capabilities provides a wider range of tools for creating effective maps than do many pure GIS programs. Bentley PowerMap is a comprehensive, stand-alone, and self-contained production mapping solution with a rich set of map creation and cleanup tools. It supports the viewing of 2D and 3D data at the same time, and is particularly effective when working with 3D data. You can plot both vector and raster data. For GIS users, PowerMap functionality is also available through the GeoGraphics extension.
Figure 4. The spatial data for this project was compiled in ArcGIS and then exported to Macromedia Freehand, which was used to prepare the final maps for printing. The environmental analysis identifies the sensitive environmental resources that may need to be protected along the eastern portion of the I-80 corridor.
Autodesk Map 3D 2005. AutoCAD users who want to work with geospatial data can use this precision mapping application integrated with AutoCAD 2005. Autodesk Map is intended for GIS practioners who are involved with creating, maintaining, and producing maps. The integration of 2D and 3D data makes it easier to communicate even the most complex data. The same printing and plotting functionality of AutoCAD is available through Map.
Manifold System Release 6 Professional Edition is a powerful, easy-to-use GIS and mapping system that also includes CAD-like editing capabilities. Formatting effects provide a greater level of control over the appearance of your map. The program automatically generates labels, colors, points, and lines, and you can modify or input them manually one at a time. It creates points from any TrueType font or from any graphics file, and uses asymmetric line styles to create arrows and leader lines.
MapInfo Professional v7.5, the industry's leading business mapping solution, lets you perform sophisticated and detailed data analysis to increase revenue, lower costs, boost efficiency, and improve service with location-based intelligence. Also included with MapInfo is an extensive collection of predesigned maps that you can use as is or modify to meet specific needs. To help print high-quality maps, MapInfo MapShop runs as an add-on module in MapInfo Professional. Map details such as scale, date, name, and number are updated on-the-fly so you don't have to update each map individually. There are standard print templates that make it easy for even a novice to add a level of consistency to printed maps.
Process, Print, and Output GIS DataThere are also programs that produce maps from geospatial data exported from GIS programs.
DCS (Digital Cartographic Suite) is for cartographers who want to simplify the process of developing robust maps from geospatial data. The idea behind DCS is to provide an editing environment that reduces the amount of time for producing production-ready color separates by minimizing the time spent in feature and symbol editing, rasterization, and check plotting. The suite consists of Dynamo, a base mapping product that uses real-time editable topology, Dynamo Terrain Modeler for creating elevation data and relief maps, and DynaGen for generating map products at varying scales from a single high-resolution database.
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Because GIS maps often contain a massive amount of data and are printed on large sheets, the overall size of the files is considerable. As a result, GIS maps can take a long time to print, and data can often be truncated. One common technique used to print vector-based GIS drawings is to first convert the vector data into a raster image via a technique called rasterization.
HyperXpress, for example, is a high-performance printing and plotting software program that uses a RIP (raster image processor) to print large files. The RIP software dramatically decreases the time it takes to print the large, complex images that result from most GIS projects. HyperXpress handles files that exceed 5GB in size and processes hybrid files that contain raster and vector data. This tool can dramatically minimize printing problems—especially those that always seem to occur when you have a big deadline looming.
One particularly nice feature is the true print previewer that lets you proof and edit a map before making the final print. There are modules designed specifically to integrate HyperXpress into programs such as ArcGIS and MapInfo.
ERDAS IMAGINE is designed specifically to process digital imagery such as aerial photographs, satellite images, and other raster data. IMAGINE includes image analysis tools to solve just about any problem involving geospatial data. Some of the newest capabilities include import and export utilities as well as enhanced 3D visualization. The mosaic tool makes it easy to piece together different images and print even the largest maps. Several tools for resolution merging and editing ensure that the optimized resolution is used for printed maps.
Illustration programs such as Canvas 9, Adobe Illustrator 10, Macromedia Freehand MX, CorelDRAW 11, and Corel Designer 10 provide sophisticated image editing, page layout, and drawing tools for producing great-looking maps. The graphic editing tools in these programs are much more powerful and easy to use than are those of GIS programs. The limitation is that these types of programs don't have GIS capabilities.
I know of a number of design and planning professionals who use a GIS program to manipulate geospatial data, and then export that data into an illustration program to take advantage of its graphic tools. Even though this isn't the most efficient way to generate maps, it's an effective way to create beautiful ones.
ACD Systems addresses this problem with CANVAS 9 GIS +, which includes geospatial tools to bridge the gap between GIS and graphic design. The program is geared toward GIS professionals who want a greater level of artistic control over the final layout of a map. CANVAS 9 GIS + also contains support for a range of GIS import filters as well as robust export engines that produce GeoTIFF and SHAPE file formats. You can apply text attributes, label location, rotation angle, and collision detection settings, and dynamically replace and modify map symbols one at a time to create the visual quality you desire for your map.