"""Class definition for the MODIS snow cover fraction data type.
.. module:: mod10
:synopsis: Definition of the MOD10 class
.. moduleauthor:: Kostas Andreadis <kandread@jpl.nasa.gov>
"""
import dbio
from datetime import timedelta
import datasets
from ftplib import FTP
import tempfile
import subprocess
import glob
import shutil
import modis
import logging
table = "snow.mod10"
[docs]def dates(dbname):
dts = datasets.dates(dbname, table)
return dts
[docs]def download(dbname, dts, bbox):
"""Downloads the Terra MODIS snow cover fraction data product MOD10 for
a specific date *dt* and imports them into the PostGIS database *dbname*."""
log = logging.getLogger(__name__)
res = 0.005
url = "n5eil01u.ecs.nsidc.org"
tiles = modis.findTiles(bbox)
if tiles is not None:
ftp = FTP(url)
ftp.login()
for dt in [dts[0] + timedelta(dti) for dti in range((dts[-1] - dts[0]).days + 1)]:
try:
ftp.cwd("SAN/MOST/MOD10A1.005/{1:04d}.{2:02d}.{3:02d}".format(url, dt.year, dt.month, dt.day))
files = [f for f in ftp.nlst() if any(
f.find("h{0:02d}v{1:02d}".format(t[1], t[0])) > 0 for t in tiles)]
files = filter(lambda s: s.endswith("hdf"), files)
outpath = tempfile.mkdtemp()
for fname in files:
with open("{0}/{1}".format(outpath, fname), 'wb') as f:
ftp.retrbinary("RETR {0}".format(fname), f.write)
proc = subprocess.Popen(["gdal_translate", "HDF4_EOS:EOS_GRID:{0}/{1}:MOD_Grid_Snow_500m:Fractional_Snow_Cover".format(outpath, fname), "{0}/{1}".format(outpath, fname).replace("hdf", "tif")], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
out, err = proc.communicate()
log.debug(out)
tifs = glob.glob("{0}/*.tif".format(outpath))
proc = subprocess.Popen(
["gdal_merge.py", "-a_nodata", "-9999", "-o", "{0}/snow.tif".format(outpath)] + tifs, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
out, err = proc.communicate()
log.debug(out)
proc = subprocess.Popen(["gdal_calc.py", "-A", "{0}/snow.tif".format(outpath), "--outfile={0}/snow1.tif".format(
outpath), "--NoDataValue=-9999", "--calc=\"(A<101.0)*(A+9999.0)-9999.0\""], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
out, err = proc.communicate()
log.debug(out)
proc = subprocess.Popen(["gdalwarp", "-t_srs", "'+proj=latlong +ellps=sphere'", "-tr", str(
res), str(-res), "{0}/snow1.tif".format(outpath), "{0}/snow2.tif".format(outpath)], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
out, err = proc.communicate()
log.debug(out)
proc = subprocess.Popen(["gdal_translate", "-a_srs", "epsg:4326", "{0}/snow2.tif".format(outpath), "{0}/snow3.tif".format(outpath)], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
out, err = proc.communicate()
log.debug(out)
dbio.ingest(
dbname, "{0}/snow3.tif".format(outpath), dt, table, False)
shutil.rmtree(outpath)
except:
log.warning("MOD10 data not available for {0}. Skipping download!".format(
dt.strftime("%Y-%m-%d")))
[docs]class Mod10(object):
def __init__(self):
"""Initialize MOD10 snow cover fraction object."""
self.statevar = ["swq"]
self.obsvar = "snow_cover"
self.res = 0.005
self.stddev = 0.05
self.tablename = table