Who is JSON and why does he sometimes have a GEO? An exploration of web mapping file typesRead Now
Written by Sarah Dewees
So I'm not a computer person and I don't know code, but I want to make maps that people can interact with. And so far my foray into web mapping has left me a bit lost. I need to know a new language or two ( Java script, css, html) and even some of the words that are in English don't make sense. There seem to be few programs out there to help us illiterate folks code, but you have to be able to get your data onto their server. There are so many file types available and at the same time so many that are unavailable. The questions I hope to answer for myself and graciously share with you are; which file type is best? and how to convert from one file type to another.
Supported Web mapping file types:
Below are a list of file types that I could upload to Carto, Mapbox, Google My Maps and ArcGIS online. There are probably more but this seemed like a good baseline. These are also all less code required sites.
After lots of looking there does not seem to be one universal file type with web mapping. I didn't really expect there to be, but wanted to check. GeoJSON seem to be pretty popular in web mapping since its already in Java Script and many of the web mapping libraries are in Java Script. Unfortunately, in my experience GeoJSON files gave me the most trouble to create. ArcMap only converts to .json files which give me an error in Mapbox (and possibly others) that I can't figure out how to fix it.
So how do I get to the elusive GeoJSON....
Transforming one dataset into another - its magic! Without using code
Unfortunately this does not work with raster data you must first convert to a vector format for uploading.
Using Carto -
Ok, so you can upload lots of different file types into Carto and then download (click on the dataset, then export) them as a .geojson or KML (also csv and shapefile). The only problem I found with this so far is that while your data is on Carto, unless you have a paid for account, the data is public. There doesn't seem to be a limit to how much data you can upload to Carto and you can delete it afterwards but if your data is sensitive this might not be the best plan.
Using QGIS -
Bring data into QGIS, right click on it and go to 'save as', then select geojson and make sure all parameters are appropriate and save where you want it. If you need to edit it convert after editing as QGIS cannot edit geojson.
These are the only non-code methods that I have been able to find that work for me. Please share any methods you find or know of for file conversion!
5/3/2017 07:51:42 am
Thanks, Sarah! Your efforts are appreciated, and your research has made my hill a little easier to climb
5/5/2017 09:44:46 am
Thanks Sarah! I'm sure I will come back to this post in the future when I'm trying to make a web map for our final project. I appreciate the effort and headache you endured to figure this out- thanks for doing the legwork!
5/14/2017 01:28:12 pm
This got me curious about GeoJSON vs JSON and finding a more comprehensive explanation about some of the details and found this site that does a pretty good job.
5/18/2017 02:51:46 pm
Thank you Sarah! I appreciate the tip on QGIS. I'm glad that we have an alternative option to ArcMap, and knowing that it does a decent job at converting file types is extremely useful information. :D
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Blog posts are written by students in the Interactive Map Design course at Portland Community College.