Using ArcGIS Online
This will be a lightning quick introduction to cloud-based GIS from the lens of ESRI’s ArcGIS Online (or AGOL). AGOL is a rapidly evolving technology, so we won’t concentrate on the precise execution of specific tasks. Rather the goal is to introduce you to what GIS looks like when freed from the limitations of desktop computing and is able to leverage cloud-based technology.
We’ll cover the the following:
- What is AGOL? Desktop GIS - vs - ArcGIS Online - vs - Enterprise GIS
- Adding data to AGOL and sharing it with others
- Exploring AGOL data
- Analyzing data using AGOL
- Cloud based tools in AGOL’s broader ecosystem
1. Desktop GIS - vs - ArcGIS Online - vs - Enterprise GIS
Desktop GIS
So far, the vast majority of our learning GIS at NSOE has been done using “desktop GIS”, specifically ArcGIS Pro. What does this imply? Traditionally this means:
- All the data used in your analysis are stored on your desktop i.e., the machine in front of you (or a mapped drive).
- All processing is done on your desktop (or a single virtual machine)
- To share your data, analysis, and/or results, you need to copy or move files from machine to machine.
So, with desktop GIS, you need to supply your own hardware and your own data. You license the software to run analyses and manage data, and licenses are usually provided on a per-machine basis.
ArcGIS Online
ArcGIS Online, as its name implies, is a an on-line resource typically accessed via a web browser. You can search and browse data, create maps, and even perform analyses without needing any specialized software or data stored on your local machine. Thus, in contrast to desktop GIS:
- Data are stored and managed “in the cloud”.
- All processing of the data is done on remote servers.
- Sharing data and products are done via web links.
Resources are all remote in the AGOL platform, you don’t need a high-end machine and many datasets are accessible as on-line resources. Here you often pay for a subscription to access the resource. With ArcGIS Online, you will additionally pay for credits that count toward storing your own data or executing particularly intensive processing tasks, both of which consume server resources.
Enterprise GIS
Enterprise GIS is a bit of a hybrid between desktop GIS and ArcGIS Online. From a user’s perspective, Enterprise GIS appears quite similar to ArcGIS Online. The key difference is that, instead of using ESRI’s hardware to host data and run centralized processes, you set up an ArcGIS online portal on your own servers. The servers used to host the portal are usually higher end machines than your typical desktop computers, costing a bit more and often requiring dedicated management (ensuring they are always available and backed up).
With enterprise GIS, you again need to purchase software and also budget management of the server, and of course you have the upfront cost of the server equipment. But you don’t need subscription fees or credit accounting as all the heavy lifting is done on your own equipment.
ESRI and Non-ESRI Options for Enterprise GIS
ESRI is the big name in all of this, but not the only company offering Enterprise GIS solutions.
GeoServer (http://geoserver.org/) is an open source alternative to hosting data on servers or a cluster of servers. It provides both viewing and access to geospatial data via web services, as AGOL does. Admittedly, I have limited experience with GeoServer. With all open source software, you get the benefit of having a much larger body of programmers improving and expanding the platform, but it comes at the cost of uncertain stability and minimal documentation and no dedicated support. Yes, it’s free, but your time is not, and if you go this route, it’s best to understand that you will be likely spending significantly more time setting it up and managing it.
With data storage, management, and distribution a key component in enterprise GIS, many commercial and open source database management systems, or DBMS, can also provide enterprise GIS services. Oracle*** and **Microsoft SQL Server* are the giants in commercial DMBS, providing proven and robust products, but at a premium price. (Though Microsoft often has generous agreements with education and non-profit communities, as does ESRI for that matter.) PostgreSQL*** seems to be the leading open source DMBS. Some smaller end DMBS packages are **MySQL* and *SQLite*, both of which are open source, but are note designed for enterprise scale database management.
In addition to standard, online access points to large relational databases, these DBMS also have plugins or adaptors that allow you to include geometric features in their databases. Additionally, some also include mechanisms to perform spatial analysis. I again have very limited experience with GIS data in these formats; typically, if you are going this route you are less likely an aspiring environmental manager and more someone with a dedicated technology background. (They involve quite a bit of computer savvy!) Still, these technologies are useful to know, even as – or perhaps especially as –environmental managers.
Summary
If you are ever in the position of setting up your own shop, know that you have options for how you store your GIS data and run analyses. The options sketched out above each have different costs layouts (in $ and time) and expandability. Up until recently, for shops the up to the scale of a small to mid-size NGO, my recommendation was to invest in one or a few high end desktops and go the desktop GIS route. Why? Because it’s proven to be capable and stable, doesn’t require too much computer support know-how, and has a rich user community. However, I’m now starting to embrace ESRI’s ArcGIS Online platform for reasons I’ll layout in detail next…
2. AGOL as a Content Management System
3. Exploring AGOL data
- Finding data