I am curious if anybody has seen a situation like this?
Using ModelBuilder in ArcGIS 10.2.2, I:
Create a FGDB > Create Mosaic Dataset > Add Rasters to Mosaic Dataset (800+ tiffs) > Edit Raster Function (NDVI and Apply ColorMap)
The area of coverage is an entire county, which for the vast majority looks just as I expect it to look. The exceptions are 1 -2 pixel gaps which fall exactly around horizontal footprint lines in the NDVI temporary raster that is created. The input tiffs are perfectly aligned, zero overlap and zero gaps. I was able to break the county imagery into smaller sections and created FGDB for each section, then run the rest of my model on each subsection, and the NDVI rasters had no gaps. This involved lots of trial and error. Half county sections produced the same error, as did quarter county sections. Finally, eighth county sections produced a usable product. This was fine initially, but I this involves copying and recopying 100s of GBs of data (time expensive!) What's worse, is that there does not seem to be an exact data size that will/will not produce the errors.