Automated Cartography

Automated cartography is the process by which maps are produced with the help of computers, as opposed to the established manual methods.

Introduction
Automated map production workflows can be understood by parsing the term into its constituent words. According to Buckley and Watkins: '“Automation” is the operation or control of equipment, a process, or a system by a machine rather than by hand. “Map production” includes map compilation, or “assembling and fitting together the geographical data you will include in your map”, as well as other elements on the page Map production also involves map construction in which the map is placed on the page or multiple related maps are placed on multiple pages, and associated elements like graphs or tables are added to the pagemor pages. In addition, map production involves the output of a final product. A “workflow” is a process and/or procedure in which certain tasks are completed. So, “automated map production workflows” are machine‐driven processes that result in the completion of tasks that relate to the compilation, construction, or output of a map product.'

The full text of the paper is available on the Esri Mapping Center, under Other Resources > Publications (mappingcenter.esri.com).

Background
According to Joseph K. Berry in GIS Technology in Environmental Management, the early 1970's saw computer mapping automate the map drafting process. 'The points, lines and areas defining geographic features on a map are represented as an organized set of X,Y coordinates. These data drive pen plotters that can rapidly redraw the connections at a variety of colors, scales, and projections. The map image, itself, is the focus of this automated cartography.

The groundbreaking work done in this time created many of the underlying concepts and procedures of modern GIS technology. 'An obvious advantage of computer mapping is the ability to change a portion of a map and quickly redraft the entire area. Updates to resource maps, such as a forest fire burn, which previously took several days, can be done in a few hours.

'The less obvious advantage is the radical change in the format of mapped data — from analog inked lines on paper, to digital values stored on disk.'

Spatial Database Management
Berry notes that during the early 1980's, the change in format and computer environment of mapped data was utilized. Spatial database management systems (SDBMS) linked computer mapping capabilities with traditional database management capabilities. In these systems, identification numbers are assigned to each geographic feature, such as a timber harvest unit or wildlife management parcel. For example, a user is able to point to any location on a map and instantly retrieve information about that location. Alternatively, a user can specify a set of conditions, such as a specific vegetation and soil combination, and all locations meeting the criteria of the geographic search are displayed as a map (Berry).

Possibilities
There is, as yet, no completely automated process for making maps. However, a great deal of progress in the automatic cartographic process has been made, especially in the fields of label placement, contour generation, generalization, and automated feature extraction. See also Automatic label placement

According to Buckley and Watkins, automated processes may be applied to:
 * Many maps with the same theme but different extents.
 * Many maps with the same extent but different themes.
 * Many maps with the same extent and the same theme, but the data for the theme changes over time.

NOTE: A theme is a set of related geographic features such as streets, parcels, or rivers, along with their attributes. All features in a theme share the same coordinate system, are located within a common geographic extent, and have the same attributes. Themes are similar to layers.

An extent is the minimum bounding rectangle (xmin, ymin and xmax, ymax) defined by coordinate pairs of a data source. All coordinates for the data source fall within this boundary.

'For all three of these candidates for automation, a single map laid out on a single page is the starting point. The layout can then be modified, text elements and map features can be updated, and themes can be turned on or off – all through automation. In addition to maps and page layouts, other candidates for automation are reports or publications whose content includes text, graphs, and charts that will accompany the map or maps. Using automation, it is possible to compile the maps, along with one or many of these other types of documents, into a single output file to create a multi‐page product. In this scenario, pages with different layouts and content can be combined into a single cartographic product.'

Census Bureau Achievement
In addition to commercial software, U.S. Government agencies have understandably been heavily involved in automating the process of map production.

For the 2010 census, the U.S. Census Bureau designed and produced millions of unique paper maps. According to Schell and Spahlinger the high volume needed a non-interactive mapping process. The Bureau decided to create its own in-house system called CAMPS, or Census Automated Map Production System.

The system works with the Bureau's Oracle Spatial database. According to the paper by Schell and Spahlinger, 'CAMPS attempts to mimic the process that a cartographer would follow when creating a map by encapsulating all possible decisions in pre-populated parameter tables. Parameters are logically grouped into several database tables related to the map content they describe, with records for a single set of mapping parameters (called a project) linked from table to table by unique identifiers, or keys. The following is a list of the parameter table names and a brief summary of each table.

Parameters – Basic map information, for example, project code.

Canvas – Index, parent, and inset, each with separate rules.

Sheeting – Description of sheets, for example height and width.

Layers – What will appear on each canvas/sheet combination.

Symbology – Named symbology for each layer.

Styles – Style for each symbology, for example color and font.

Definitions – Definition for each style, for example color values.

Marginalia – Description of marginal elements.

Postprocess – Description of supplemental files and embedded properties.

In order for the system to be entirely automated, the parameters describe everything from basic information about where in the database to source the map subject to very low-level details like specific color definitions and fonts.'

The full text of the paper is available on the Web, one site being that of the American Society for Photogrammetry and Remote Sensing (www.asprs.org).