Scale of Geographic Measurement and Analysis can both Create and Propagate Uncertainty
As defined by Monmonier (1995) that the reliability and accuracy of Cartography depends on its source of information mostly because other design principals are standard. There are so many famous or rather notorious examples in history related to the errors due to mapping and misinformation. With the advancement in technology and rapid use of maps for commercial, defense and personal purposes the national mapping agencies are now focusing more on moving from precise or hard information which is precise and accurate to another form of soft or uncertain information to converge multiple maps. This leads to wrong scaling and dubious lineage because soft data is not accurate, the source scale is inconsistent between multiple maps, and the data can have positional inaccuracy. These new mapping systems which are rapidly being created consider all the data as hard data and assume the accuracy even though that is not the case. It doesn’t make any distinction between soft and hard data over space or by attributes (Monmonier, 1995).
Multiple maps when joined together have a huge probability of generating errors of scale. As there are multiple sources for multiple maps, the data for some can be hard and for others it can be soft. The methodology used and accuracy might also vary. Now when all this is combined, the outcome cannot have complete accuracy. This system, when used creates uncertainty because of the multiple possibilities of inaccuracies.
Main Types of Commercial GIS Software Products Currently Available
According to GIS Geography (2016), there are hundreds of GIS software products available however following are some of the most commonly known and used:
ArcGIS from Esri – They are the market leaders in this industry since the inception in 1970s.
Geomedia from Hexagon Geospatial – They are the main competitors of Esri. This is primarily used by government agencies and military due to the solution based approach.
MapInfo Professional by Pitney Bowes – This is a popular product due to its location intelligence feature. It is very useful in locating stores and other places, improving insurance risks and driving larger profits.
Global Mapper by Blue Marble – This is an end to end solution in GIS which is helpful for both beginners and expert GIS users.
Manifold GIS by Manifold – Their USP is providing all the commercial world class GIS features but at a very competitive price; almost half from its competitors.
Smallworld by GE – This is focused on the market share of technical expert GIS users with a dedicated serving area in utilities.
Bentley Map – This is a combination of CAD and GIS. They provide both two and three dimensional views for the users.
MapViewer and Surfer by Golden Software – This is yet another amazing product in GIS space with capabilities of grids and contour. This is simple to learn and use.
Maptitude by Caliper Corporation – This is very intuitive and good platform for creating amazing maps by the users. It uses very nice mathematical algorithms to create causal relationships.
SuperGIS by Supergeo Technologies – This is a look alike of ArcGIS with a faster processing of data. It also offers some unique applications including analytics of biodiversity (GIS Geography, 2016).
Role of Database Management Systems in GI Systems
As described in the chapter by Stoter & Zlatanova (2006) that since the evolution of Geographical Information System in early 1990s, database management systems, DBMS, have become an important and integral part of the GIS systems. The DBMS have the capabilities to store and process very large volumes of data in a way that its consistency and accuracy is maintained. Any GI system needs a lot of data to be processed and utilized and DBMS does exactly that for these systems. Since its integration with GI systems, DBMS has been used in multiple ways and it is still evolving. The following figure shows how it is being evolved.
Figure 1. Evolution of DBMS usage and integration with GIS.
It started with a dual architecture with DBMS and spatial components as independent functionalities. Then it moved to a layered architecture as shown in the middle and finally to an integrated architecture which is used today in which the components are integrated and merged together to provide a transparent and faster processing for the users. In recent times, a lot of progress has been made in managing both spatial and non-spatial data and information using an integrated DBMS commonly referred to as a geo-DBMS (Stoter & Zlatanova, 2006).
Key Geographic Database Data Types and Functions
As explained by Longley et al. (2005) in their book, following are the key elements in geographic databases:
Entity - This is the most granular element in the database which is a building block with a specific phenomenon of interest
Object - This is a representation of entities
Entity types - Common and related entities stored in a database are represented by entity types
Attribute - Any characteristic of an entity which will be used is represented by the attributes
Layers - Spatial entities and objects need to be grouped into layers also called themes
Metadata - This is the data about data including data types, definitions and relationships
Spatial Reference System table - This relates to the integration and usage of data into GI system.
Once we understand these basic elements, the next thing to look at is the data types. There are essentially two types of spatial database types; spatial warehouse and GIS spatial database. Following are the spatial data types:
Point – These are the objects which are only represented by their location
Line – These are moving through or connected in space
Region – A two dimensional extended representation of space
Partition – These are the adjacency representation between regions
Networks – These are connected objects using vertical and horizontal objects including rivers, roads and power lines (Longley et al., 2005)
The Choices Available to Compose a Map
Even though there are many choices available to compose maps ranging from building an application from scratch versus using an out of the box application. The GIS software available today including those listed above in the second section give very nice capabilities to create and compose maps. Let us look at the first one; ArcGIS:
ArcGIS (2016) clearly mention the easy steps to compose a map, which are:
Choose a base map – It is like choosing the basic layout and structure. Many options are available to be chosen from and based on the specific usability and need, the user can choose the most appropriate base map
Add Layers – This step easily adds all the objects under the layer category
Change Style – In this step, using drop downs, specific styles can be given to individual objects in the map for either highlighting those objects or providing consistency
Configure pop-ups – To make the maps user friendly and intuitive, the functionalities of messaging at the run time using pop-ups is available in this step
Save map – After the above steps and composition of a map, the user can simply save the map locally or to the cloud where others can review, work or use these maps (AcrGIS, 2016).
References
ArcGIS. (2016). Make your first Map. Retrieved May, 2016 from https://doc.arcgis.com/en/arcgis-online/create-maps/make-your-first-map.htm
GIS Geography. (2016). Commercial GIS Software: List of Commercial Mapping Software. Retrieved May, 2016 from http://gisgeography.com/commercial-gis-software/
Longley, P., Goodchild, M., Maguire, D. & Rhind, D. (2005). Geographic Information Systems and Science, 2nd Edition. NJ, New Jersey. John Wiley & Sons Ltd.
Monmonier, M. (1995). Drawing the Line: Tales of Maps and Cartocontroversy. NY, New York. Holt.
Stoter, A. & Zlatanova, C. (2016). Frontiers of Geographic Information Technology. Berlin, Germany. Springer.
