To run this on EMR, do something akin to the following (with buckets changed as appropriate):
aws emr create-cluster \
--name "NED Conversion" \
--log-uri s3://ned-13arcsec.openterrain.org/logs/ \
--release-label emr-4.0.0 \
--use-default-roles \
--auto-terminate \
--ec2-attributes KeyName=stamen-keypair \