Were you able to locate a solution for this project? I notice how much this looks like a heat map as well and want you to be aware that heatmaps are a coming very soon - Coming Soon: New features in Tableau and you may be interested in trying the current beta to determine if this would work for this situation.
If I'm understanding the problem correctly, I have an idea on how to do this... I made a quick example and attached (wind speed map as an image and US state capitals as a point dataset on top).
To make this, I did some outside processing in QGIS:
- Georeferenced the wind speed GIF to obtain the left/right/top/bottom coordinates for the black outline. I used a Census boundary shapefile of states for my reference points and just picked a handful of distinct locations (e.g., the tip of the Olympic peninsula in WA state, the southernmost point in TX, etc.). Before georeferencing, I reprojected the US boundaries to Albers equal area. The result of this is a geotiff.
- Added the georeferenced file to QGIS and grabbed the bounding coordinates from properties
- Added a shapefile with coordinates in lat/lon to QGIS. Reprojected to Albers equal area.
- Added an X and Y column for the shapefile so that I had columns with the x,y locations in the projected Albers equal area projection
- Add my shapefile (or a CSV...you aren't going to use the geometry from the shapefile, so the format doesn't matter...you just need the new x,y columns with the projected coordinates)
- Add the geotif to Tableau as a background image.
- Set the left/right/top/bottom coordinates based on the geotiff bounding box identified in QGIS.
- Drop the x,y coordinates on the viz.
If I've understood your problem correctly, I think you should be able to automate translating your points into a viz this way...
georeference.twbx 1.3 MB