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Download Sentinel 1 POE and RES orbit files from aux.sentinel1.eo.esa.int
"""Get Sentinel-1 orbit file(s) from ESA archive website"""
import argparse
import logging
import os
import re
import sys
from datetime import datetime
from pyroSAR.examine import ExamineSnap
import requests
from pathlib import Path
from typing import Union
from lxml import html
def download_file(url: str, directory: Union[Path, str] = '.', chunk_size=None, retries=1, backoff_factor=1) -> str:
"""Download a file
Args:
url: URL of the file to download
directory: Directory location to place files into
chunk_size: Size to chunk the download into
retries: Number of retries to attempt
backoff_factor: Factor for calculating time between retries
Returns:
download_path: The path to the downloaded file
"""
logging.info(f'Downloading {url}')
try:
download_path = Path(directory) / url.split("/")[-1]
except AttributeError:
raise requests.exceptions.InvalidURL(f'Invalid URL provided: {url}')
with requests.get(url, stream=True) as s:
if s.status_code == 200:
with open(download_path, "wb") as f:
for chunk in s.iter_content(chunk_size=chunk_size):
if chunk:
f.write(chunk)
return str(download_path)
def _get_asf_orbit_url(orbit_type, platform, timestamp):
ot = orbit_type.upper().split('_')[1]
search_url = f"http://aux.sentinel1.eo.esa.int/{ot}/{timestamp[:4]}/{timestamp[4:6]}/{timestamp[6:8]}/"
response = requests.get(search_url)
if response.status_code == 200:
tree = html.fromstring(response.content)
file_list = [file for file in tree.xpath('//a[@href]//@href')
if file.startswith(platform) and file.endswith('.EOF')]
d1 = 0
best = None
for file in file_list:
file = file.strip()
t = re.split('_', file.replace('T', '').replace('V', ''))
if len(t) > 7:
start = t[6]
end = t[7].replace('.EOF', '')
if start < timestamp < end:
d = ((int(timestamp) - int(start)) + (int(end) - int(timestamp))) / 2
if d > d1:
best = file
d1 = d
if best is not None:
return search_url + best
return None
def downloadSentinelOrbitFile(
granule: str, directory = None, orbit_types=('AUX_POEORB', 'AUX_RESORB')
):
"""Download a Sentinel-1 Orbit file
Args:
granule: Granule name to find an orbit file for
directory: Directory to save the orbit files into
orbit_types: Iterable of orbit file types to attempt to download, in order of preference
Returns: Tuple of:
orbit_file: The downloaded orbit file
"""
if not directory:
try:
auxdatapath = ExamineSnap().auxdatapath
except AttributeError:
auxdatapath = os.path.join(os.path.expanduser('~'), '.snap', 'auxdata')
osvdir = os.path.join(auxdatapath, 'Orbits', 'Sentinel-1')
outdir_poe = os.path.join(osvdir, 'POEORB')
outdir_res = os.path.join(osvdir, 'RESORB')
else:
outdir_poe = directory
outdir_res = directory
outdir = {
'AUX_POEORB': outdir_poe,
'AUX_RESORB': outdir_res
}
orbit_file = None
for orbit_type in orbit_types:
platform = granule[0:3]
time_stamps = re.split('_+', granule)[4:6]
orbit_url = _get_asf_orbit_url(orbit_type.lower(), platform, time_stamps[0].replace('T', ''))
try:
orbit_file = download_file(orbit_url, directory=outdir[orbit_type])
break
except:
continue
return orbit_file
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