Source code for act.discovery.surfrad

Function for downloading data from
NOAA Surface Radiation Budget network

from datetime import datetime
import os

    from urllib.request import urlopen
except ImportError:
    from urllib import urlopen

[docs]def download_surfrad_data(site=None, startdate=None, enddate=None, output=None): """ Function to download data from the NOAA Surface Radiation Budget network. Parameters ---------- site : str 3 letter NOAA site identifier. Required variable List of sites can be found at startdate : str The start date of the data to acquire. Format is YYYYMMDD. Required variable enddate : str The end date of the data to acquire. Format is YYYYMMDD output : str The output directory for the data. Set to None to make a folder in the current working directory with the same name as *datastream* to place the files in. Returns ------- files : list Returns list of files retrieved """ if (site is None) or (startdate is None): raise ValueError('site and startdate need to be set') site = site.lower() site_dict = { 'bnd': 'Bondville_IL', 'tbl': 'Boulder_CO', 'dra': 'Desert_Rock_NV', 'fpk': 'Fort_Peck_MT', 'gwn': 'Goodwin_Creek_MS', 'psu': 'Penn_State_PA', 'sxf': 'Sioux_Falls_SD', } site_name = site_dict[site] # Convert dates to day of year (doy) for NOAA folder structure s_doy = datetime.strptime(startdate, '%Y%m%d').timetuple().tm_yday year = datetime.strptime(startdate, '%Y%m%d').year if enddate is None: enddate = startdate e_doy = datetime.strptime(enddate, '%Y%m%d').timetuple().tm_yday # Set base URL url = '' # Construct output directory if output: # Output files to directory specified output_dir = os.path.join(output) else: # If no folder given, add datastream folder # to current working dir to prevent file mix-up output_dir = os.path.join(os.getcwd(), site_name + '_surfrad') if not os.path.isdir(output_dir): os.makedirs(output_dir) # Set up doy ranges, taking into account changes for a new year prev_doy = 0 if e_doy < s_doy: r = list(range(s_doy, 366)) + list(range(1, e_doy + 1)) else: r = list(range(s_doy, e_doy + 1)) # Set filename variable to return filenames = [] # Loop through each doy in range for doy in r: # if the previous day is greater than current, assume a new year # i.e. 365 -> 001 if prev_doy > doy: year += 1 # Add filename to url file = site + str(year)[2:4] + str(doy) + '.dat' new_url = url + site_name + '/' + str(year) + '/' + file # Write each file out to a file with same name as online output_file = os.path.join(output_dir, file) try: print('Downloading ' + file) with open(output_file, 'wb') as open_bytes_file: open_bytes_file.write(urlopen(new_url).read()) filenames.append(output_file) except Exception: pass prev_doy = doy return filenames