Hi Michael,
I did the geoprocessing analysis on ArcGIS Pro. I first used the 'Mosaic to New Raster' tool. my parameter is as follows - input over 100 rasters at once, set spatial reference for raster to WGS_1984_Web_Mercator_Auxiliary_Sphere, pixel type to 8 bit unsigned, cellsize to 0, mosaic operator to last and mosaic colormap mode to last. Run
My second step was the 'Mosiac' tool. In the parameter I input same rasters as the first step, Target raster was the created mosiac to new raster, Mosaic operator was set to minimum, Mosaic colormap mode was set to last, ignore Background value was set to 0, No data value also set to 0. and Run.
Here's a link to what am trying to accomplish. ArcGIS Web Application
Thanks