Grab tiles from CartoDB and calculate population in those tiles from the census:
SELECT CDB_OVERLAP_SUM(
ST_TRANSFORM(
CDB_XYZ_Extent(603,769,11), 4326),
'us_census_acs2013_5yr_census_tract_copy ',
'total_pop',
'stuartlynn')
where CDB_OVERLAP_SUM can be found here : https://github.com/CartoDB/crankshaft/blob/master/pg/sql/0.0.1/03_overlap_sum.sql Download tiles to ./tiles
Train NN to predict the population off the tile set using keras.