I thought it worthwhile pulling together a series of posts on offline maps and how to get started. This an area in which we have particular expertise.
Many of the most popular mobile apps available today include maps. Apps like Pokemon Go and Uber are two excellent examples. Built in GPS in smartphones and tablets has enabled users to ask a multitude of ‘where questions’: Where is the closest PokéStop? Where is my Uber driver?
The popularity of consumer mobile mapping apps is now moving to the enterprise, to save money, or make money. GIS is a technology which quietly sits behind many mobile enterprise mapping apps. GIS generates maps from raw data and allows users to ask both simple and complex ‘where questions’. More on GIS later.
Offline Maps and How to Get Started Part 1
Mobile maps often rely on wireless connectivity to work. As an example, when you see your Uber driver heading towards your location on the map, quietly in the background your smartphone is getting information back over wireless on the changing location of that driver.
You guessed it. Your Uber app would stop working!
That leads us nicely into our discussion of offline maps. Imagine you are working in an area which either completely lacks wireless connectivity, or has poor connectivity. Your mobile map will either not work or take an age to load or change. That is both frustrating and inefficient.
In the early days of mobile development, apps which provided offline maps were simply impossible to build. That has changed.
More than that, as we will discuss in this blog post series, there are now many ways to build mobile offline maps.
Offline Maps Base-maps and Layers
Let’s start with the basics. Maps are made up of two core elements: base-maps, and layers. Base-maps are just as the name suggests. They include World Imagery, World Street Map, World Topographic, Ocean Basemap, and more. Base-maps provide the map context: roads, buildings, parks, contours etc. They are simply a collection of pictures or tiles. OpenStreetMap is an example of a base-map source.
Layers are what sit on-top of a base-map. Think of map markers. These could be restaurants (point features), parks (polygon features) or rivers (line features). A layer represents features on the ground, and are symbolized accordingly. “Show me all the Mexican restaurants near my current location”, would be a ‘where question’ you might ask. And hey-presto the map shows icons on the map which show the locations of all Mexican restaurants nearby. Tap on one of these icons and a pop up shows information about that particular restaurant. That is another feature of layers, they are often interactive.
Interactive is very useful, and editable is another related layer option. Let’s move to a commercial use of offline maps to illustrate, our true focus in this article series. You are a utility worker using a mobile mapping app outdoors. Today you are inspecting a power pole. You tap the point on the mobile map which represents the power pole you are inspecting. In the pop up the pole material is listed as wood. You can see it is aluminum. If this layer is editable you can change that field from wood to aluminum. Now suppose the next power pole you need to inspect is not on the mobile map. You need to add it. Again an editable layer will allow you to add this new point feature. These updates will be pushed back to the data source via your wireless connection for all to see. Get the idea?
Let’s close out part 1 of this blog series here. In the next article we will discuss how we take base-maps and layers offline.
Feel free to contact us on 801-733-0723 if you have questions.
Matt is a Principal at WebMapSolutions. Follow him on Twitter: @webmapsolutions