Source Code for Module ivs.catalogs.kepler

  1  """ 
  2  Retrieve light curves from the Kepler satellite mission. 
  3  """ 
  4  import urllib 
  5  import os 
  6  import astropy.io.fits as pf 
  7  import logging 
  8  import numpy as np 
  9  from ivs.catalogs import mast 
 10  from ivs.units import conversions 
 11  from ivs.inout import ascii 
 12  from ivs.inout import fits 
 13  from ivs import config 
 14   
 15  logger = logging.getLogger("CAT.KEPLER") 
 16   
 17 -def download_light_curve(KIC,directory=''): 
 18      """ 
 19      Download a light curve file from the data archive. 
 20       
 21      @param KIC: kic number 
 22      @type KIC: integer 
 23      @param directory: directory to save data to, defaults to cwd 
 24      @type directory: string 
 25      @return: list of filenames 
 26      @rtype: list of str 
 27      """ 
 28      #-- get info on what is available 
 29      results,units,comms = mast.search('kepler/data_search',ktc_kepler_id=KIC) 
 30      #-- reconstruct the links 
 31      links = [] 
 32      for name in results['Dataset Name']: 
 33          num = '%09d'%(int(KIC)) 
 34          folder = num[:4] 
 35          links.append("http://archive.stsci.edu/pub/kepler/lightcurves/%s/%s/%s_llc.fits"%(folder,num,name.lower())) 
 36      filenames = [] 
 37      #-- and download the files 
 38      logger.info("Found %d public/proprietary light curves for KIC%s"%(len(links),KIC)) 
 39      for base_url in links: 
 40          url = urllib.URLopener() 
 41          filename = os.path.basename(base_url) 
 42          if directory: 
 43              filename = os.path.join(directory,filename) 
 44          try: 
 45              filen,msg = url.retrieve(base_url,filename=filename) 
 46          except IOError: 
 47              logger.info('... %s is proprietary'%(base_url)) 
 48          else: 
 49              logger.info('... downloaded %s'%(filename)) 
 50              filenames.append(filen) 
 51          url.close() 
 52           
 53      return filenames 
 54   
 55 -def get_data(KIC): 
 56      """ 
 57      Retrieve Kepler timeseries from a remote data repository. 
 58       
 59      Fields are 'HJD','flux','e_flux','bkg','quarter'. 
 60       
 61      @param KIC: kic number or list of filenames 
 62      @type KIC: integer or list 
 63      @return: data, header 
 64      @rtype: recarray, dict 
 65      """ 
 66      times = [] 
 67      flux = [] 
 68      e_flux = [] 
 69      background = [] 
 70      quarter = [] 
 71      if isinstance(KIC,str) or isinstance(KIC,int): 
 72          filenames = download_light_curve(KIC) 
 73      else: 
 74          filenames = KIC 
 75      for filename in filenames: 
 76          header = pf.getheader(filename) 
 77          data = fits.read2recarray(filename,ext='LIGHTCURVE') 
 78          times.append(data['TIME']+2454833.) 
 79          flux.append(data['SAP_FLUX']) 
 80          e_flux.append(data['SAP_FLUX_ERR']) 
 81          background.append(data['SAP_BKG']) 
 82          quarter.append(np.ones(len(data))*header['quarter']) 
 83      data = np.rec.fromarrays([np.hstack(times),np.hstack(flux),np.hstack(e_flux), 
 84                                np.hstack(background),np.hstack(quarter)], 
 85                                names=['HJD','flux','e_flux','bkg','quarter']) 
 86      return data,header 
 87      
 88   
 89 -def systematics(units='muHz'): 
 90      """ 
 91      Return a list of known systematic effects from the Kepler satellite. 
 92      """ 
 93      ffile = config.get_datafile('catalogs/kepler','systematics.dat') 
 94      systems = ascii.read2recarray(ffile) 
 95      systems['frequency'] = conversions.nconvert(systems['unit'],units,systems['frequency']) 
 96      systems['e_frequency'] = conversions.nconvert(systems['unit'],units,systems['e_frequency']) 
 97      systems['w_frequency'] = conversions.nconvert(systems['unit'],units,systems['w_frequency']) 
 98      return systems 
 99