GEOG 865
Cloud and Server GIS

Overview

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So far in our exploration of software as a service (SaaS) providers, we have focused largely on map design and construction. We’ve also seen how datasets can be uploaded and stored on the cloud. In this lesson we’ll move forward and look at how GIS tools and algorithms can be invoked in a SaaS environment.

You got a taste of GIS as a service back when you used CARTO to aggregate farm dropoff points to neighborhoods. This required an algorithm to run determining the neighborhood where each point was located. The neighborhoods layer was then updated with a field showing the count of all points inside. If this were run locally it would require you to install GIS or other spatial data processing software. Offloading this operation to the cloud requires you to solely focus on the input and output data.

Many other GIS operations are possible in the cloud; all that’s needed are some known input/output formats and some server logic that can then process the data. A popular input/output format is vector features. You’ve seen how there are lots of known formats for that, such as GeoJSON, CSV, KML, etc. Once the server receives these, it can perform operations such as buffering, intersection, routing, drive time analysis, etc. and send back the result in the form of more vectors, an image, or perhaps even textual reports. These analyses might incorporate sophisticated datasets from the cloud provider, such as road networks, address databases, or demographic information. Cloud providers can charge a metered fee, deducting money or credits for each operation performed, or they can charge flat monthly fees for different tiers of capabilities.

Although Esri is not the only company that offers GIS operations as a cloud service, it is clearly an area where they specialize. Esri ArcGIS Desktop software has hundreds of tools running all kinds of GIS operations. The challenge for Esri (and other cloud service providers) is to expose these kinds of tools online through an interface that’s intuitive to people who may have never used any GIS before. These users may know exactly what they want to accomplish, but would not be familiar with GIS terms like clip, union, buffer, etc. Companies offering GIS as a service must clearly define these terms or simplify them. Pause and spend a few minutes looking over the Perform Analysis page to see how Esri uses a combination of graphical icons and simplified terms to explain the spatial analysis capabilities in ArcGIS Online.

In this lesson you'll use GIS services on ArcGIS Online to derive service areas, join demographic variables to those, and export data for further analysis outside the cloud. These are just a few of the many possible operations offered by ArcGIS Online, but they should give you a taste of how to invoke the analysis and manage Esri service credits.

Lesson Objectives

At the successful completion of this lesson, you should be able to:

  • Understand how spatial analysis tools can be exposed through software as a service (SaaS)
  • Use analysis tools in ArcGIS Online to solve geographic problems