# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
import zipfile
import os.path as op
import os
import re
# from pyrocko.util import urlopen
import numpy as num
from pyrocko import util, config
from . import tile, dataset
citation = '''
Farr, T. G., and M. Kobrick, 2000, Shuttle Radar Topography Mission produces a
wealth of data. Eos Trans. AGU, 81:583-585.
Farr, T. G. et al., 2007, The Shuttle Radar Topography Mission, Rev. Geophys.,
45, RG2004, doi:10.1029/2005RG000183. (Also available online at
http://www2.jpl.nasa.gov/srtm/SRTM_paper.pdf)
Kobrick, M., 2006, On the toes of giants-How SRTM was born, Photogramm. Eng.
Remote Sens., 72:206-210.
Rosen, P. A. et al., 2000, Synthetic aperture radar interferometry, Proc. IEEE,
88:333-382.
'''
[docs]class AuthenticationRequired(Exception):
pass
class SRTMGL3(dataset.TiledGlobalDataset):
def __init__(
self,
name='SRTMGL3',
data_dir=op.join(op.dirname(__file__), 'data', 'SRTMGL3'),
raw_data_url='https://mirror.pyrocko.org/e4ftl01.cr.usgs.gov/'
'MEASURES/SRTMGL3.003/2000.02.11'):
dataset.TiledGlobalDataset.__init__(
self,
name,
432001, 216001, 1201, 1201,
num.dtype('>i2'),
data_dir=data_dir,
citation=citation,
region=(-180., 180., -60., 60.))
self.raw_data_url = raw_data_url
self._available_tilenames = None
self.config = config.config()
def tilename(self, itx, ity):
itx -= 180
ity -= 90
if ity >= 0:
s = 'N%02i' % ity
else:
s = 'S%02i' % -ity
if itx >= 0:
s += 'E%03i' % itx
else:
s += 'W%03i' % -itx
return s
def available_tilenames(self):
if self._available_tilenames is None:
fpath = op.join(self.data_dir, 'available.list')
if not op.exists(fpath) or os.stat(fpath).st_size == 0:
util.ensuredirs(fpath)
# remote structure changed, we would have to clawl through
# many pages. Now keeping tile index here:
self.download_file(
'https://mirror.pyrocko.org/e4ftl01.cr.usgs.gov/'
'MEASURES/SRTMGL3.003/2000.02.11/available.list', fpath)
# url = self.raw_data_url + '/'
# f = urlopen(url)
# data = f.read().decode()
# available = re.findall(
# r'([NS]\d\d[EW]\d\d\d)\.SRTMGL3\.hgt', data)
#
# f.close()
#
# with open(fpath, 'w') as f:
# f.writelines('%s\n' % s for s in available)
with open(fpath, 'r') as f:
available = [
s.strip() for s in f.readlines()
if re.match(r'^[NS]\d\d[EW]\d\d\d$', s.strip())]
self._available_tilenames = set(available)
return self._available_tilenames
def tilefilename(self, tilename):
return tilename + '.SRTMGL3.hgt.zip'
def tilepath(self, tilename):
fn = self.tilefilename(tilename)
return op.join(self.data_dir, fn)
def download_tile(self, tilename):
fpath = self.tilepath(tilename)
fn = self.tilefilename(tilename)
url = self.raw_data_url + '/' + fn
try:
# we have to follow the oauth redirect here...
self.download_file(url, fpath)
except Exception as e:
raise e
def download(self):
for tn in self.available_tilenames():
fpath = self.tilepath(tn)
if not op.exists(fpath):
self.download_tile(tn)
def get_tile(self, itx, ity):
tn = self.tilename(itx, ity)
if tn not in self.available_tilenames():
return None
else:
fpath = self.tilepath(tn)
if not op.exists(fpath):
self.download_tile(tn)
zipf = zipfile.ZipFile(fpath, 'r')
rawdata = zipf.read(tn + '.hgt')
zipf.close()
data = num.frombuffer(rawdata, dtype=self.dtype)
assert data.size == self.ntx * self.nty
data = data.reshape(self.nty, self.ntx)[::-1, ::]
return tile.Tile(
self.xmin + itx*self.stx,
self.ymin + ity*self.sty,
self.dx, self.dx, data)
if __name__ == '__main__':
import sys
util.setup_logging('pyrocko.topo.srtmgl3', 'info')
if len(sys.argv) != 2:
sys.exit('usage: python -m pyrocko.topo.srtmgl3 download')
if sys.argv[1] == 'download':
srtmgl3 = SRTMGL3()
srtmgl3.download()
