Chapter 3:
Chapter 3 focuses on the experience builder, which utilizes multiple applications to create an informational experience. There’s many different flexible widgets with different functions to display information in a very organized way. The experience builder uses HTML and Javascript, but doesn’t require any programming knowledge.
What’s interesting about the experience builder is the apps and widgets can all be connected and dynamic, meaning that as long as the source data is consistently updated, the applications will be up to date. This is generally true with web services like this but it seems especially useful for the experience builder. After playing around with it, It’s incredibly intuitive and allows a lot of customization.
Chapter 4:
Chapter 4 is about mobile GIS and other non-PC ways to display GIS information. It also teaches how to build an application for mobile devices, but you can also make them for location-based services, volunteered geographic information, virtual and augmented reality.
Mobile services can allow for better positioning technologies than wired devices, which can be used for navigation or data collection. Typically, these are done via GPS, Wi-Fi, or bluetooth.
While WebGIS is inherently browser based, most mobile applications are native, meaning they’re on the device rather than being accessed by a web browser. This allows them to run better, as well as access more information about the device that browsers cannot access. Making these types of applications usually requires programming knowledge.
This chapter also discusses Survey123, a service that creates surveys. The data is stored to a hosted cloud, allowing up-to-date source information.
The other types of apps and platforms for Mobile GIS are:
Location-based Services: Tracks and provides local information based on a user’s current location (usually found via GPS)
Volunteered geographic information: Users voluntarily provide geographic information to be shared. Typically used locally in applications such as Mapping apps to report traffic, road work, accidents, police vehicles, etc.
Virtual Reality: A 3D simulation of a map that allows interaction and mimics how our eyes and bodies view and interact with the world. I fail to see how this would be very useful with GIS, however.
Augmented Reality: An overlay of computer information over a real-world camera view of the environment, using your device’s location and other spatial information, such as tilt and height.
Using the experience builder, I could create a real-time updated site that uses the information about historical disasters, as well as crime statistics, cost of living, etc. across different cities to show the ideal places to live.
Chapter 5:
An on-premise enterprise is a locally/privately hosted version of a service. WebGIS is typically stored on a globally accessible cloud, but you can create privately hosted server versions of WebGIS for security and connectivity.
WebGIS servers host a lot of data: millions of maps, rasters, shapefiles, tables, text files etc. There are many methods of storing and calling data that are used by WebGIS to optimize the user experience.
Caching is essentially a method of storing frequently accessed data in a way that it can be easily called for repeated or future use without having to call to the source. In the case of GIS, the rasters can be cached as image files on the client machine in order to display them without having to call to the host server every time the user zooms or pans the map display.
Vector tile data is a type of layer that varies in size based on data density to optimally store and display the data.
Feature tiles are similar to vector tile data in that it simplifies and optimizes the data for display. It stores the viewing extent as a limited number of tiles in the cache, allowing them to be easily called when the extent changes.
Chapter 6:
Chapter 6 covers data on an additional dimension (temporal) and how this is used to make constantly-updated real-time data be used and displayed in WebGIS. Theres 4 main types of spatiotemporal data:
Moving: data that moves across space over time (e.g. a car’s position)
Discrete: data that occurs in a space at a time (e.g. geotagging services that report accidents/construction)
Stationary: data at a space that changes over time (e.g. weather stations collecting data)
Change: data that changes its spatial extent over time (e.g. the extent of a wildfire spreading)
Temporal data can be stored as either a point in time or duration of time, with a start and end.
Internet of Things (IoT) is a connected network of sensors and connections that collect and exchange data. It’s essentially an entire system of information that is gathered and shared.
The IoT gathers trillions of data, much of it is geospatiotemporal and used in GIS applications. The examples above and more are stored in data centers where they can be accessed to create maps with real-time data.
In the previous week, I mentioned an idea for a real-time web application that uses a lot of this updated data to track crime statistics, weather, cost of living, etc. to create a map of U.S. cities that shows where is the best place to live. Using the extent of the U.S. however might be too large to do feasibly within this semester, but doing this within Ohio seems more reasonable.
Chapter 7:
This chapter covers 3D web scenes and how to work with the 3D maps in WebGIS. 3D scenes are a way to visualize maps more intuitively and with greater detail than 2D maps. These maps can be cartographic, which are stylized, or photorealistic, which uses real images of the surface to accurately represent how it looks. There’s many other visual stylization options used to make the scenes more accurate, visually appealing, or better convey the information.
3D mapping is related to the increased interest in virtual reality and the metaverse, both indoors and outdoors virtual environments. Potential uses include urban planning, using the 3D environments to predict how building certain projects will affect the city’s aesthetics or markets.
A potential application of 3D mapping is creating a 3D viewshed to show the views from various apartments in a city, and how building new projects might affect those views. This could give potential customers an idea of their view, which could affect if they want to buy/rent.