Beispiel #1
0
def azza_to_radec(az, za, MJD, fctr=350.0, atm=1010.0, temp=283.0, humid=0.5, scope='GBT'):
    """
    azza_to_radec(az, za, MJD):
        Return RA and DEC (J2000 in deg) from AZ and ZA (in deg) at MJD.  Keyword params
           are fctr=350.0, atm=1010.0, temp=283.0, humid=0.5, scope='GBT'.
    """
    scope, x, lon, lat, hgt = s.sla_obs(0, scope)
    microns = 3e8/(fctr*1e6)*1e6
    app_rarad, app_decrad =  s.sla_oap('a',az*DEGTORAD,za*DEGTORAD,MJD,
                                       0.0,-lon,lat,hgt,0.0,0.0,temp,atm,humid,microns,0.0065)
    ra2000, dec2000 = s.sla_amp(app_rarad, app_decrad, MJD, 2000.0)
    return ra2000*RADTODEG, dec2000*RADTODEG
Beispiel #2
0
def azza_to_radec(az,
                  za,
                  MJD,
                  fctr=350.0,
                  atm=1010.0,
                  temp=283.0,
                  humid=0.5,
                  scope='GBT'):
    """
    azza_to_radec(az, za, MJD):
        Return RA and DEC (J2000 in deg) from AZ and ZA (in deg) at MJD.  Keyword params
           are fctr=350.0, atm=1010.0, temp=283.0, humid=0.5, scope='GBT'.
    """
    scope, x, lon, lat, hgt = s.sla_obs(0, scope)
    microns = 3e8 / (fctr * 1e6) * 1e6
    app_rarad, app_decrad = s.sla_oap('a', az * DEGTORAD, za * DEGTORAD, MJD,
                                      0.0, -lon, lat, hgt, 0.0, 0.0, temp, atm,
                                      humid, microns, 0.0065)
    ra2000, dec2000 = s.sla_amp(app_rarad, app_decrad, MJD, 2000.0)
    return ra2000 * RADTODEG, dec2000 * RADTODEG
Beispiel #3
0
def translate_header(fits_file, skip, output_subints):
    fits_hdr = fits_file['PRIMARY'].header
    subint_hdr = fits_file['SUBINT'].header
    fil_header = dict.fromkeys(fil_header_keys, None)

    if fits_hdr['TELESCOP'] in telescope_ids:
        fil_header["telescope_id"] = telescope_ids[fits_hdr['TELESCOP']]
    else:
        fil_header["telescope_id"] = -1
    if fits_hdr['BACKEND'] in machine_ids:
        fil_header["machine_id"] = machine_ids[fits_hdr['BACKEND']]
    else:
        fil_header["machine_id"] = -1

    fil_header["data_type"] = 1  # filterbank
    # Get filename in a way that is safe for old versions of pyfits
    # (i.e. using private attribute)

    #Let's get the center of our intended output file.
    #Right now I'm assuming we're in search mode and that we'll take
    #The subint offset from the first file and add skip +
    #output_subints / 2 subints to get the position of the telescope.
    time_subint = subint_hdr['TBIN'] * subint_hdr['NSBLK']
    time_offset = subint_hdr['NSUBOFFS'] * time_subint + \
                  skip * time_subint

    #Let's set some variables that we'll use to update our position
    #via pyslalib
    type = "A"  #We need this for SLA
    dtmp = 0.0  #Delta UT
    atm = 1010.0  #Local atmospheric pressure in mB
    temp = 283.0  #Local temperature in DegK
    humid = 0.5  #Local relative humidity in range 0.0-1.0
    tlr = 0.0065  #Tropospheric lapse rate (DegL/meter)
    eq = 2000.0  #Julian epoch of mean place
    microns = 3e8 / fits_hdr['OBSFREQ'] * 1e6 * 1e6
    az = radians(fits_file['SUBINT'].data[0]['TEL_AZ'])  #azimuth
    za = radians(fits_file['SUBINT'].data[0]['TEL_ZEN'])  #zenith
    tstart = fits_hdr['STT_IMJD'] + \
                           fits_hdr['STT_SMJD']/86400.0 + \
                           fits_hdr['STT_OFFS']/86400.0 + \
                           time_offset/86400.0  #tstart of new file
    #Now let's get the MJD of the center of the new file
    #so that we can update the RA/DEC for the new file

    MJD = tstart + (time_subint * output_subints / 2) / 86400.0

    #Ok, I think we're set to update our position.  Let's use slalib
    #to get the position of the telescope

    telecope,telescope_name,tel_lon,tel_lat,tel_hgt = \
      sla.sla_obs(0,fits_hdr['TELESCOP'])
    #Now we have tel_lon,tel_lat and tel_ght.  We need to flip the lon

    tel_lon = -tel_lon

    #Let's get the geocentric apparent RA and DEC
    rap,dap = sla.sla_oap(type,az,za,MJD,dtmp,tel_lon,tel_lat,tel_hgt,\
                      dtmp,dtmp,temp,atm,humid,microns,tlr)

    #OK, for reals we are almost there  Let's convert to FK5 (mean place)

    rmn, dmn = sla.sla_amp(rap, dap, MJD, eq)
    hours, hmin, hsec = presto.hours2hms(degrees(rmn) / 15.0)
    deg, dmin, dsec = presto.deg2dms(degrees(dmn) / 15.0)

    fil_header["src_raj"] = float(hours * 10000.0 + hmin * 100.0 + hsec)
    fil_header["src_dej"] = float(deg * 10000.0 + dmin * 100.0 + dsec)

    fn = fits_file._HDUList__file.name
    fil_header["rawdatafile"] = os.path.basename(fn)
    fil_header["source_name"] = fits_hdr['SRC_NAME']
    fil_header["barycentric"] = 0  # always not barycentered?
    fil_header["pulsarcentric"] = 0  # whats pulsarcentric?
    fil_header["az_start"] = fits_file['SUBINT'].data[0]['TEL_AZ']
    fil_header["za_start"] = fits_file['SUBINT'].data[0]['TEL_ZEN']
    #   fil_header["src_raj"] = float(fits_hdr['RA'].replace(':',''))
    #   fil_header["src_dej"] = float(fits_hdr['DEC'].replace(':',''))
    fil_header["tstart"] = fits_hdr['STT_IMJD'] + \
                           fits_hdr['STT_SMJD']/86400.0 + \
                           fits_hdr['STT_OFFS']/86400.0 + \
                           time_offset/86400.0
    fil_header["tsamp"] = subint_hdr['TBIN']
    fil_header["nbits"] = None  # set by user. Input should always be 4-bit.

    # first channel (fch1) in sigproc is the highest freq
    # foff is negative to signify this
    fil_header["fch1"] = fits_hdr['OBSFREQ'] + \
                         np.abs(fits_hdr['OBSBW'])/2.0 - \
                         np.abs(subint_hdr['CHAN_BW'])/2.0
    fil_header["foff"] = -1.0 * np.abs(subint_hdr['CHAN_BW'])
    fil_header["nchans"] = subint_hdr['NCHAN']
    fil_header["nifs"] = subint_hdr['NPOL']

    return fil_header
Beispiel #4
0
def translate_header(fits_file,skip,output_subints):
    fits_hdr = fits_file['PRIMARY'].header
    subint_hdr = fits_file['SUBINT'].header 
    fil_header = dict.fromkeys(fil_header_keys,None)

    if fits_hdr['TELESCOP'] in telescope_ids:
        fil_header["telescope_id"] = telescope_ids[fits_hdr['TELESCOP']]
    else:
        fil_header["telescope_id"] = -1
    if fits_hdr['BACKEND'] in machine_ids:
        fil_header["machine_id"] = machine_ids[fits_hdr['BACKEND']]
    else:
        fil_header["machine_id"] = -1

    fil_header["data_type"] = 1 # filterbank
    # Get filename in a way that is safe for old versions of pyfits
    # (i.e. using private attribute)

    #Let's get the center of our intended output file.  
    #Right now I'm assuming we're in search mode and that we'll take
    #The subint offset from the first file and add skip + 
    #output_subints / 2 subints to get the position of the telescope.
    time_subint = subint_hdr['TBIN']*subint_hdr['NSBLK']
    time_offset = subint_hdr['NSUBOFFS'] * time_subint + \
                  skip * time_subint 

    #Let's set some variables that we'll use to update our position
    #via pyslalib
    type = "A"         #We need this for SLA
    dtmp = 0.0         #Delta UT
    atm  = 1010.0      #Local atmospheric pressure in mB
    temp = 283.0       #Local temperature in DegK
    humid = 0.5        #Local relative humidity in range 0.0-1.0
    tlr = 0.0065       #Tropospheric lapse rate (DegL/meter)
    eq = 2000.0        #Julian epoch of mean place
    microns = 3e8 / fits_hdr['OBSFREQ']*1e6*1e6
    az = radians(fits_file['SUBINT'].data[0]['TEL_AZ']) #azimuth
    za = radians(fits_file['SUBINT'].data[0]['TEL_ZEN']) #zenith
    tstart = fits_hdr['STT_IMJD'] + \
                           fits_hdr['STT_SMJD']/86400.0 + \
                           fits_hdr['STT_OFFS']/86400.0 + \
                           time_offset/86400.0  #tstart of new file
    #Now let's get the MJD of the center of the new file 
    #so that we can update the RA/DEC for the new file

    MJD = tstart + (time_subint * output_subints / 2)/86400.0

    #Ok, I think we're set to update our position.  Let's use slalib
    #to get the position of the telescope 
  
    telecope,telescope_name,tel_lon,tel_lat,tel_hgt = \
      sla.sla_obs(0,fits_hdr['TELESCOP'])
    #Now we have tel_lon,tel_lat and tel_ght.  We need to flip the lon

    tel_lon = -tel_lon
    
    #Let's get the geocentric apparent RA and DEC
    rap,dap = sla.sla_oap(type,az,za,MJD,dtmp,tel_lon,tel_lat,tel_hgt,\
                      dtmp,dtmp,temp,atm,humid,microns,tlr)

    #OK, for reals we are almost there  Let's convert to FK5 (mean place)

    rmn,dmn = sla.sla_amp(rap,dap,MJD,eq)
    hours,hmin,hsec = presto.hours2hms(degrees(rmn)/15.0)
    deg,dmin,dsec = presto.deg2dms(degrees(dmn)/15.0)


    fil_header["src_raj"] = float(hours*10000.0 + hmin*100.0 +  hsec)
    fil_header["src_dej"] = float(deg*10000.0 + dmin*100.0 + dsec)

    fn = fits_file._HDUList__file.name
    fil_header["rawdatafile"] = os.path.basename(fn) 
    fil_header["source_name"] = fits_hdr['SRC_NAME']
    fil_header["barycentric"] = 0 # always not barycentered?
    fil_header["pulsarcentric"] = 0 # whats pulsarcentric?
    fil_header["az_start"] = fits_file['SUBINT'].data[0]['TEL_AZ']
    fil_header["za_start"] = fits_file['SUBINT'].data[0]['TEL_ZEN']
#   fil_header["src_raj"] = float(fits_hdr['RA'].replace(':',''))
#   fil_header["src_dej"] = float(fits_hdr['DEC'].replace(':',''))
    fil_header["tstart"] = fits_hdr['STT_IMJD'] + \
                           fits_hdr['STT_SMJD']/86400.0 + \
                           fits_hdr['STT_OFFS']/86400.0 + \
                           time_offset/86400.0
    fil_header["tsamp"] = subint_hdr['TBIN']
    fil_header["nbits"] = None # set by user. Input should always be 4-bit.

    # first channel (fch1) in sigproc is the highest freq
    # foff is negative to signify this
    fil_header["fch1"] = fits_hdr['OBSFREQ'] + \
                         np.abs(fits_hdr['OBSBW'])/2.0 - \
                         np.abs(subint_hdr['CHAN_BW'])/2.0
    fil_header["foff"] = -1.0*np.abs(subint_hdr['CHAN_BW'])
    fil_header["nchans"] = subint_hdr['NCHAN']
    fil_header["nifs"] = subint_hdr['NPOL']

    return fil_header