Building a Real-Time GIS Services Workflow

Brent Porter

Center for Space Research

bporter@csr.utexas.edu

Experience

  • Web-based GIS

  • Desktop/os-level Applications/Scripts

  • GIS Infrastructure & Architecture

So, I am always torn in these kinds of meetings!

Do I talk about the programming and the lessons learned creating that code?

Or do I talk about the processes I set up to make the Real Time App a success?

Let me apologize now if you were looking for the coding option - I think in this venue going through the process is useful.

Today's Outline

  • Design of application data

  • Example application - MOVES

  • Workflow development

Let's discuss real time data...

or really any 'living' GIS mapping application or data flow

Living?

  • One that may be different from access point to access point
  • In other words, not static
  • That is really what we mean we say 'Near Real Time' or 'Real Time' data/application

Which isn't to say...

Much of our discussion will work with static data too....

So.

Back to Design Characteristics. In particular Data design.

  • One to a FEW operational layers (data streams)
    • Temporal component that is intrinsic to the value of the data that is being visualized
    • Not too many attributes! (Users don't need to see 50 fields - think 10 as a rule of thumb)
    • Not too many features. This is the web - and now more often than not it is also mobile. Too many features will make your app slow/unstable
    • Not too complex - ask yourself if you need data with large numbers of vertices.

Data Design Continued

  • Also you want some common geographic features - something familiar to the users
    • Think of the common mapping patterns online
      • Aerials/Streets
    • Remember who your users are - if they are the public they will not be as familiar as you with your application. Using a common set of features sets them up to succeed.

Operational Layers - examples

  • Precipitation accumulation
  • Precipitation forecast
  • Geotagged photos
  • Radar
  • River gauges

Base Layer - examples

  • Seamless or Patchwork Aerials or Satellite Imagery
  • Streets based vector layer(s) - like open streetmap, bing maps, google maps or map quest maps
  • Other thematic vector layer(s) - topographic, oceanographic, etc.
  • Vector tiles - think Streets map like but YOU get to decide how it looks (colors/weights/etc)

Other Design considerations

  • UI/UX
    • mobile first, responsive, native app, etc
    • Bootstrap, SASS/Less
  • Application Design
    • collection of pages, single page app, thick client app
  • Architecture Design
    • MVC, MVVC, etc

Unfortunately
 each of those could be a separate presentation

Today's Outline

  • Design of application data

  • Example application - MOVES

  • Workflow development

Working Example

  • MOVES stands for Modeling, Observations and Visualization for Emergency Support (MOVES) Network
  • http://magic.csr.utexas.edu/public/views/

Today's Outline

  • Design of application data

  • Example application - MOVES

  • Workflow development

Putting it all together

Workflow Considerations

  • Data - incoming
  • Data - storage
  • Data - access
  • Data - visualization

Data - incoming

  • Need to use some tool to gather/process data into formats that can be used to store data
  • Java/Python are my two favorite candidates
    • We have expertise with each
    • GIS api availability to allow you to focus on collection rather than creation of functionality
  • GDAL/ogr2ogr - http://www.gdal.org/ We use this primarily for the ogr2ogr functionality that dovetails nicely with our data storage solution.

Data - storage

  • PostgreSQL
  • with PostGIS  installed
  • using built in functions to create javascript object notation (JSON) snippets
  • https://www.postgresql.org/
  • http://postgis.net/
  • But... we still do have some data stored on file as well! - for uses such as image tiles in rest endpoint access

Data - access

  • Rest endpoints! YMMV on how to implement these but I am currently using Nodejs for most of my rest endpoints - https://nodejs.org/en/
  • Also both the pg/pg-connect libraries and restlet library for Nodejs from the npm js repository - https://www.npmjs.com/
  • Make sure to emit JSON from the rest end point queries - http://json.org/

Data - visualization

  • LeafletJS - http://leafletjs.com/
    • very intuitive, open source javascript library that is easy to begin creating mapping applications with
    • also has many third party plug-ins like ESRI (see next bullet)
  • ESRI leaflet plugin - https://github.com/Esri/esri-leaflet
    • allows you to access ArcGIS server tiled maps, feature layers and other ESRI Rest-based technology
  • JQuery - http://jquery.com/ - used to integrate your spatial functionality with the common behaviors users need from a web 2.0 application.

URL

https://slides.com/organizedchaos/building-a-gis-services-workflow/

Questions?

email - bporter@csr.utexas.edu

twitter - brentaporter

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