I have a student that completed a project on invasive species using ArcGIS desktop. This was a raster analysis project and she has 10 rasters of the state of Kentucky that she would like to put into a story map. These are huge datasets each. Is ther

[AmyNemon]

I have a student that completed a project on invasive species using ArcGIS desktop.  This was a raster analysis project and she has 10 rasters of the state of Kentucky that she would like to put into a story map.   These are huge datasets each.   Is there a way to get those maps into ArcGIS Online for the storymap without having to resort to just creating a jpeg out of each?

[JosephKerski]

Hi Amy:

You are touching on a number of important considerations when serving data sets – raster or otherwise – in ArcGIS Online, considering speed of rendering, your end goal, raster vs vector layers, and desktop capabilities vs. online capabilities.  

See this example of a map that I created in ArcGIS Online for a lesson on wind power siting:

https://www.arcgis.com/home/webmap/viewer.html?webmap=ccce43e8dd2a4eeab04a3af98a230ec4

Look at the “wind power class” layer. This came from NREL (the Natl Renewable Energy Lab) as a raster file.  I generalized it over several iterations until it was small enough to render quickly in ArcGIS Online.  Then, since you cannot do the “raster calculator” functions (yet) in ArcGIS Online, I vectorized it before serving it.  So, your student could do something similar for her 10 layers of Kentucky.  But I would just say that unless it adds value in doing so, she might be better off spending her time with another segment of the project.  In my case, since I needed the wind layer for people to use in the analysis, it was worth me processing the data, which to be honest took numerous hours, but if it is just to have people understanding her project in a story map, the JPG method might be the best course of action.

In another example, see this map containing some image tiles for the GEOINT MOOC that I helped Penn State with:

https://www.arcgis.com/home/webmap/viewer.html?webmap=1222e6d97abe4407906dd1d3e0e0f349 

… showing “before” and “after” images of certain new developments in the Spratly Islands off of SE Asia.

Because I was serving it in ArcGIS Online and because thousands of students would be accessing the map from all over the world with a variety of bandwidths, despite the generous donation of nearly 1 TB of Digital Globe imagery covering the whole area, I needed to cut the imagery up into small pieces and serve those as image tiles.  So, they end up, in this lesson, examining 3 or 4 islands and 2 different time periods for each, examining what is happening there and discussing why, and the environmental and political implications, and our goals for the lesson were met without serving up a massive data set.

I hope this is helpful.

Joseph Kerski