Exploring astrometry.net fits files

gistfile1.txt

# %%

dir_path = "C:\\Users\\denis\\Downloads"

corr_file = "corr.fits"
imgradec_file = "image-radec.fits"
rdls_file = "rdls.fits"

import os
from astropy.io import fits

# %%
# Load the FITS file

corr_hdulist = fits.open(os.path.join(dir_path, corr_file))
corr_hdulist.info()

# Select the second HDU
corr_hdu = corr_hdulist[1]

# Display the header information
corr_hdu.header

# Extract the data
corr_data = corr_hdu.data
#print(data)

# Print the data with column names and then the first row
print(corr_data.columns)
print(corr_data[0])
print(corr_data[1])

# Extract the first four columns of data into a numpy array
import numpy as np
x_data = corr_data['field_x']
y_data = corr_data['field_y']
ra_data = corr_data['index_ra']
dec_data = corr_data['index_dec']
data_array = np.array([x_data, y_data, ra_data, dec_data]).T

print(data_array)

# %%
# Load the image-radec FITS file
imgradec_hdulist = fits.open(os.path.join(dir_path, imgradec_file))
imgradec_hdulist.info()

# Select the second HDU
imgradec_hdu = imgradec_hdulist[1]

# Display the header information
imgradec_hdu.header

# Extract the data
imgradec_data = imgradec_hdu.data
print(imgradec_data.columns)
print(imgradec_data[0])

# %%
# Load the rdls FITS file
rdls_hdulist = fits.open(os.path.join(dir_path, rdls_file))
rdls_hdulist.info()

# Select the second HDU
rdls_hdu = rdls_hdulist[1]

# Display the header information
rdls_hdu.header

# Extract the data
rdls_data = rdls_hdu.data
print(rdls_data.columns)
print(rdls_data[0])
print(rdls_data[1])
print(rdls_data[2])

# %%
# Extract the index_id from corr_data and find the associated data in rdls_data
field_id = corr_data['field_id']
match_wieght = corr_data['match_weight']
flux_data = corr_data['flux']
print(field_id)


ra_data = []
dec_data = []
for mw, ind, x, y, flux in zip(match_wieght, field_id, x_data, y_data, flux_data):

    # # Skip all entires with a match weight smaller than 0.5
    # if mw < 0.5:
    #     continue

    # # Skip all entries with a flux smaller than 5
    # if flux <= 5:
    #     continue

    rdls_entry = rdls_data[ind]
    ra = rdls_entry['RA']
    dec = rdls_entry['DEC']

    print("x = {:8.2f}, y = {:8.2f}, ra = {:8.2f}, dec = {:8.2f}, weight = {:8.2f}, flux = {:8d}".format(x, y, ra, dec, mw, int(flux)))