Author’s Note: In 2014, as a law student at the University of Missouri–Columbia School of Law, I wrote an analysis of Missouri Revised Statute § 67.1850. That’s the Missouri statute which grants local governments several unusual powers and great control over the public’s right to access government-held GIS data. My view is that the statute’s enumerated powers run counter to good economic development practices, common sense, and the principles supporting the public’s right to government transparency as codified in the Missouri Sunshine Act. This article makes my case for either repealing or reforming § 67.1850. I’m not just repackaging an old paper for the web. I’m going to update, enhance, and provide links that demonstrate how Missouri’s local governments are misusing the statute, and ultimately harming themselves. – Chris Dunn
II. Geographic Information Systems
GIS are comprised of (1) the people who operate the system; (2) the GIS software used to manipulate (3) the GIS data, which is often called spatial data; and (4) the electronic computing, input, storage, transmission, and output devices associated with a GIS. Most just think of GIS as a computing tool used to manage information that has both a location and one or more additional attributes. Like any other tool, it can make certain jobs easier than they otherwise would be.
A. An Example of Local Government Using GIS
A Missouri county appraiser’s job requires them to view and note, among many observations, whether new construction has occurred over the past two years in their jurisdiction. The goal is to ensure that all property may be fairly and appropriately assessed for property tax purposes. In two years’ time the county’s appraisers will drive every road in their jurisdiction making complex notes for entry into the county’s tax appraisal system, which may also be a GIS system. As she drives, she will make notes and match her list of addresses and photos of assigned properties to photos from prior years. If she is in a county with the latest gear, our appraiser is collecting data on a location enabled camera which is likely determining its location and the direction it is being pointed by using the array of 24 satellites in the US Global Positioning System (“GPS”). Her location and that of the building she is appraising is accurately known. As she is taking photographs, the system she is using is recording her voice notes about the condition of the property and storing that sound file in a way which relates the record to the location where she dictated her note. Once back at the office she downloads her day’s work into the County’s GIS system. The system knows where each building is located, which buildings are in which photos and translates her voice notes to text. Because she has this technology, she is able to do her job faster and with less error. Ostensibly, every record she makes is a public record under the Missouri Sunshine Law, or is it?
The geographic portion of a GIS provides information about subjects being mapped. Location is in turn described by one of three types of feature classes, each with its own topology. Feature classes include (1) points, (2) lines, (3) polygons, and some authorities include raster data. Raster data also inherently contain attribute data which combine with location information to form a digital map of our physical world. A point is a “geometric element defined by a pair of X-Y coordinates.” Additionally, a point feature may be a “map feature that has neither length nor area at a given scale, such as a city on a world map or a building on a city map.”
A line “[o]n a map, is a shape defined by a connected series of X-Y coordinate pairs. A line may be straight or curved.” Additionally, a line may be a “feature that has length but not area at a given scale, such as a river on a world map, or a street on a city map.” A polygon “[o]n a map, [is] a closed shape defined by a connected sequence of X-Y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique.” The boundary of a single lot in a residential subdivision is a polygon. A raster topology inherently combines a spatial location with attribute data in an altogether different way than points, lines, and polygons describe the same geography. A raster is a “spatial data model that defines space as an array of equally sized cells arraigned in rows and columns, and comprised of a single or multiple bands. Each cell contains an attribute value and location coordinates.”
For example Figure 1, as shown above, shows a 6 by 6 array with a range of 16 shades of gray for each cell or raster. Values range from 1 being the lightest to 16 the darkest. Each cell’s location is also described by its X-Y position within the raster array. Aerial photography is an example of raster data..
C. All Topology Forms May Have Attributes
What makes a GIS more than just a digital mapping system is its ability to link each polygon, line, and point to a collection of attribute data. Attribute data is “[n]onspatial information about a geographic feature in a GIS usually stored in a table and linked to the feature by a unique identifier.” For example, if the geographic location of every fire hydrant in a community is known that list can be linked to a table containing attribute data. See Tables 1 and 2.
In the example tables, the light blue cell shading indicates the necessary matching data field the two tables have in common. Like most database operations, having a data field in common allows data to be joined.
D. Layers: The Union of Attribute and Geographic Data
A dataset, or layer, is GIS data with a single theme. For example, a GIS layer may contain all of the water well locations in the state, with attribute data which might include the date of drilling, well driller’s license number, and the depth of the well. A point layer like that may be as simple as a spreadsheet. Examples of commonly produced layers a local government might hold in each of the topologies are fire hydrants (point), streets or water lines (line), and parcels or precinct voting wards (polygon).
GIS information is typically organized in a number of ways. GIS data is most often stored with the layers organized by the bounded area covered or organized by the level of government the data describes. As an example, county street layer data rarely exceeds the boundary of the county and Missouri state parks are rarely found in adjoining states. In this way, GIS data is stored in a logically organized manner, just as if it were any other collection of records.
Alternatively GIS data may be stored in a proprietary database where the software manufacturer allows the GIS technician to feed data sets into the database, where the data would remain unrecognizable and unidentifiable to a casual user browsing the data with a file manager or file explorer program.
E. The Systems Aspect of GIS
GIS technicians, the people in the system, range widely in both education and experience. A typical entry level position normally requires a bachelor’s degree in one of the associated fields and several hours of GIS course work as an undergraduate. The field has recently seen the establishment of a number of Doctor of Philosophy (Ph.D.) programs to support the geospatial sector’s desire for even more highly educated professionals.
While GIS software may be obtained from open source software providers, the majority of users at the government level purchase one of the numerous commercial software packages available. The largest commercial GIS software market share is held by ESRI, which is estimated to have between forty to fifty percent of the total commercial market, with a much higher ownership of the state and local government markets.
Recent years have seen the proliferation of GIS software to platforms beyond the traditional computer workstation. GIS software is now used from survey devices like Total Stations™, GPS receivers, smart phones, tablets, laptops, and most recently with the deployment of Google Glass GIS via eyeglasses.
Location information is assembled from anyone or anything taking geographic measurements and recording attributes. Activities as varied as engineers surveying the location of a future road, surveyors mapping out a subdivision’s corner pins, a technician matching aerial photo pixels or satellite imagery to known ground locations, and even hikers uploading their day’s trek. The latest developments allow individuals, drones, aircraft, and satellites with location enabled devices to add location and attribute data to a “crowd sourced” map.
Attribute data are assembled from a similarly countless variety of sources. For instance, the State of Missouri has a database containing a record of the name, address, and all other necessary information for it to properly license every professionally licensed health care worker and facility in the state. This database had its street addresses matched to its geographic locations through a process called geocoding. Anyone with GIS software and this database might display the spatial distribution of every doctor’s office in Missouri.
For example, a doctor specializing in gerontology might use that same Missouri Physicians GIS layer to select and display only Missouri gerontologists from out of the entire layer. Displaying those specialists over the next map layer which is made to show the latest US Census data on existing and projected elder populations can yield very useful information to a doctor looking to set up a specialty practice. Next, with a few intelligently structured commands given to the GIS software, our good doctor might be able to mathematically classify multiple areas of the state by the number of potential patients, their average income, and the number of gerontologists practicing within 30 miles.
Information may be placed into a GIS by many different methods. First, information may be loaned, given, or purchased already formatted for use by the GIS. Second, information may be entered into spreadsheets manually – through a variety of techniques – and then manipulated into a GIS readable format. Third, information may be entered automatically by devices like a GPS receiver or with a laser rangefinder as used by land surveyors. Finally, information may be created by manipulating one or more existing data sets to produce a new GIS data set.
GIS data may be distributed in a raw (text or code) or more processed form. In the raw form, it may be printed out, copied digitally, or made available for download over the internet. In a processed form, GIS data may be displayed as a finished map product, as a printed map, projected through a speaker as verbal driving directions, or viewed from within an internet web browser. There are no significant limitations on the ways which GIS data may be shared which distinguish GIS data from any other publicly held data sets.
Physical storage of GIS data entails a great variability of storage media and methods. First, GIS data may be stored on a local hard drive, on a local or remote network, or archived for later use. Thus, GIS data sets are stored like any other data set. And like other data sets they are organized with some type of logical hierarchy in place. Alternatively, GIS data may be stored within a proprietary geodatabase, which is a “collection of geographic data sets…” To extract a single data set, for example to get a copy of just the county road data set, from a geodatabase requires the use of the same proprietary GIS software which assembled the geodatabase. However, no matter how GIS data sets are stored they are routinely copied and backed up in all the common ways.
GIS data does not greatly differ from the other electronic records held by a local government. The only real difference between GIS data and the rest of a government’s digital records is that GIS data have been organized in a way which allows GIS software to quickly access and manipulate these records. Often the GIS system holds the only copy, other than back up or archives, of an entire set of government records. Property records, other than deeds and like archival documents, kept primarily within GIS format are commonplace.
There are two significantly different ways of viewing GIS data. The first is the vertical view where a GIS user is able to “look down” through several data sets much like looking at a map with a rich set of features. By using the vertical view the GIS user can turn on and off layers to suit their needs and see the relationship between different layers. A person using an on line GIS web browser could turn on each of the layers they desire to view and then zoom in or out to view the map at the desired scale; for example just their neighborhood. However, they could not examine the full extent of one layer in detail by looking at all of its attribute data because that requires a horizontal view.
A horizontal view is akin to examining the entire data set and its attributes. One would want to use this view if they wanted to see patterns, gaps, omissions, overlaps, duplicate records, or any other spatial aspects of the data. An online GIS browser does not allow the user this view. To obtain a horizontal view one needs the entire data set. Additionally, one can look at multiple data sets and discover new relationships by viewing two or more data sets horizontally. Some communities make both vertical and horizontal views available. The City of Columbia offers an on-line map where a citizen can view a variety of GIS layers, or may download several layers to view an entire layer’s attribute data at once. The ability to view an entire layer at once is important to those seeking to leverage GIS’s transparency powers
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