def matchStarsResiduals(config, platepar, catalog_stars, star_dict, match_radius, ret_nmatch=False, \
sky_coords=False, lim_mag=None, verbose=False):
""" Match the image and catalog stars with the given astrometry solution and estimate the residuals
between them.
Arguments:
config: [Config structure]
platepar: [Platepar structure] Astrometry parameters.
catalog_stars: [ndarray] An array of catalog stars (ra, dec, mag).
star_dict: [ndarray] A dictionary where the keys are JDs when the stars were recorded and values are
2D list of stars, each entry is (X, Y, bg_level, level).
match_radius: [float] Maximum radius for star matching (pixels).
min_matched_stars: [int] Minimum number of matched stars on the image for the image to be accepted.
Keyword arguments:
ret_nmatch: [bool] If True, the function returns the number of matched stars and the average
deviation. False by default.
sky_coords: [bool] If True, sky coordinate residuals in RA, dec will be used to compute the cost,
function, not image coordinates.
lim_mag: [float] Override the limiting magnitude from config. None by default.
verbose: [bool] Print results. True by default.
Return:
cost: [float] The cost function which weights the number of matched stars and the average deviation.
"""
if lim_mag is None:
lim_mag = config.catalog_mag_limit
# Estimate the FOV radius
fov_w = platepar.X_res/platepar.F_scale
fov_h = platepar.Y_res/platepar.F_scale
fov_radius = np.sqrt((fov_w/2)**2 + (fov_h/2)**2)
# print('fscale', platepar.F_scale)
# print('FOV w:', fov_w)
# print('FOV h:', fov_h)
# print('FOV radius:', fov_radius)
# Dictionary containing the matched stars, the keys are JDs of every image
matched_stars = {}
# Go through every FF image and its stars
for jd in star_dict:
# Estimate RA,dec of the centre of the FOV
_, RA_c, dec_c, _ = xyToRaDecPP([jd2Date(jd)], [platepar.X_res/2], [platepar.Y_res/2], [1],
platepar)
RA_c = RA_c[0]
dec_c = dec_c[0]
# Get stars from the catalog around the defined center in a given radius
_, extracted_catalog = subsetCatalog(catalog_stars, RA_c, dec_c, fov_radius, lim_mag)
ra_catalog, dec_catalog, mag_catalog = extracted_catalog.T
# Extract stars for the given Julian date
stars_list = star_dict[jd]
stars_list = np.array(stars_list)
# Convert all catalog stars to image coordinates
cat_x_array, cat_y_array = raDecToXYPP(ra_catalog, dec_catalog, jd, platepar)
# Take only those stars which are within the FOV
x_indices = np.argwhere((cat_x_array >= 0) & (cat_x_array < platepar.X_res))
y_indices = np.argwhere((cat_y_array >= 0) & (cat_y_array < platepar.Y_res))
cat_good_indices = np.intersect1d(x_indices, y_indices).astype(np.uint32)
# cat_x_array = cat_x_array[good_indices]
# cat_y_array = cat_y_array[good_indices]
# # Plot image stars
# im_y, im_x, _, _ = stars_list.T
# plt.scatter(im_y, im_x, facecolors='none', edgecolor='g')
# # Plot catalog stars
# plt.scatter(cat_y_array[cat_good_indices], cat_x_array[cat_good_indices], c='r', s=20, marker='+')
# plt.show()
# Match image and catalog stars
matched_indices = matchStars(stars_list, cat_x_array, cat_y_array, cat_good_indices, match_radius)
# Skip this image is no stars were matched
if len(matched_indices) < config.min_matched_stars:
continue
matched_indices = np.array(matched_indices)
matched_img_inds, matched_cat_inds, dist_list = matched_indices.T
# Extract data from matched stars
matched_img_stars = stars_list[matched_img_inds.astype(np.int)]
matched_cat_stars = extracted_catalog[matched_cat_inds.astype(np.int)]
# Put the matched stars to a dictionary
matched_stars[jd] = [matched_img_stars, matched_cat_stars, dist_list]
# # Plot matched stars
# im_y, im_x, _, _ = matched_img_stars.T
# cat_y = cat_y_array[matched_cat_inds.astype(np.int)]
# cat_x = cat_x_array[matched_cat_inds.astype(np.int)]
# plt.scatter(im_x, im_y, c='r', s=5)
# plt.scatter(cat_x, cat_y, facecolors='none', edgecolor='g')
# plt.xlim([0, platepar.X_res])
# plt.ylim([platepar.Y_res, 0])
# plt.show()
# If residuals on the image should be computed
if not sky_coords:
unit_label = 'px'
# Extract all distances
global_dist_list = []
# level_list = []
# mag_list = []
for jd in matched_stars:
# matched_img_stars, matched_cat_stars, dist_list = matched_stars[jd]
_, _, dist_list = matched_stars[jd]
global_dist_list += dist_list.tolist()
# # TEST
# level_list += matched_img_stars[:, 3].tolist()
# mag_list += matched_cat_stars[:, 2].tolist()
# # Plot levels vs. magnitudes
# plt.scatter(mag_list, np.log10(level_list))
# plt.xlabel('Magnitude')
# plt.ylabel('Log10 level')
# plt.show()
# Compute the residuals on the sky
else:
unit_label = 'arcmin'
global_dist_list = []
# Go through all matched stars
for jd in matched_stars:
matched_img_stars, matched_cat_stars, dist_list = matched_stars[jd]
# Go through all stars on the image
for img_star_entry, cat_star_entry in zip(matched_img_stars, matched_cat_stars):
# Extract star coords
star_y = img_star_entry[0]
star_x = img_star_entry[1]
cat_ra = cat_star_entry[0]
cat_dec = cat_star_entry[1]
# Convert image coordinates to RA/Dec
_, star_ra, star_dec, _ = xyToRaDecPP([jd2Date(jd)], [star_x], [star_y], [1], \
platepar)
# Compute angular distance between the predicted and the catalog position
ang_dist = np.degrees(angularSeparation(np.radians(cat_ra), np.radians(cat_dec), \
np.radians(star_ra[0]), np.radians(star_dec[0])))
# Store the angular separation in arc minutes
global_dist_list.append(ang_dist*60)
# Number of matched stars
n_matched = len(global_dist_list)
if n_matched == 0:
if verbose:
print('No matched stars with radius {:.2f} px!'.format(match_radius))
if ret_nmatch:
return 0, 9999.0, 9999.0, {}
else:
return 9999.0
# Calculate the average distance
avg_dist = np.mean(global_dist_list)
cost = (avg_dist**2)*(1.0/np.sqrt(n_matched + 1))
if verbose:
print('Matched {:d} stars with radius of {:.2f} px'.format(n_matched, match_radius))
print('Avg dist', avg_dist, unit_label)
print('Cost:', cost)
print('-----')
if ret_nmatch:
return n_matched, avg_dist, cost, matched_stars
else:
return cost
def matchStarsResiduals(config, platepar, catalog_stars, star_dict, match_radius, ret_nmatch=False, \
sky_coords=False, lim_mag=None, verbose=False):
""" Match the image and catalog stars with the given astrometry solution and estimate the residuals
between them.
Arguments:
config: [Config structure]
platepar: [Platepar structure] Astrometry parameters.
catalog_stars: [ndarray] An array of catalog stars (ra, dec, mag).
star_dict: [ndarray] A dictionary where the keys are JDs when the stars were recorded and values are
2D list of stars, each entry is (X, Y, bg_level, level, fwhm).
match_radius: [float] Maximum radius for star matching (pixels).
min_matched_stars: [int] Minimum number of matched stars on the image for the image to be accepted.
Keyword arguments:
ret_nmatch: [bool] If True, the function returns the number of matched stars and the average
deviation. False by default.
sky_coords: [bool] If True, sky coordinate residuals in RA, dec will be used to compute the cost,
function, not image coordinates.
lim_mag: [float] Override the limiting magnitude from config. None by default.
verbose: [bool] Print results. True by default.
Return:
cost: [float] The cost function which weights the number of matched stars and the average deviation.
"""
if lim_mag is None:
lim_mag = config.catalog_mag_limit
# Estimate the FOV radius
fov_radius = getFOVSelectionRadius(platepar)
# Dictionary containing the matched stars, the keys are JDs of every image
matched_stars = {}
# Go through every FF image and its stars
for jd in star_dict:
# Estimate RA,dec of the centre of the FOV
_, RA_c, dec_c, _ = xyToRaDecPP([jd2Date(jd)], [platepar.X_res/2], [platepar.Y_res/2], [1], \
platepar, extinction_correction=False)
RA_c = RA_c[0]
dec_c = dec_c[0]
# Get stars from the catalog around the defined center in a given radius
_, extracted_catalog = subsetCatalog(catalog_stars, RA_c, dec_c, jd, platepar.lat, platepar.lon, \
fov_radius, lim_mag)
ra_catalog, dec_catalog, mag_catalog = extracted_catalog.T
# Extract stars for the given Julian date
stars_list = star_dict[jd]
stars_list = np.array(stars_list)
# Convert all catalog stars to image coordinates
cat_x_array, cat_y_array = raDecToXYPP(ra_catalog, dec_catalog, jd,
platepar)
# Take only those stars which are within the FOV
x_indices = np.argwhere((cat_x_array >= 0)
& (cat_x_array < platepar.X_res))
y_indices = np.argwhere((cat_y_array >= 0)
& (cat_y_array < platepar.Y_res))
cat_good_indices = np.intersect1d(x_indices,
y_indices).astype(np.uint32)
# cat_x_array = cat_x_array[good_indices]
# cat_y_array = cat_y_array[good_indices]
# # Plot image stars
# im_y, im_x, _, _ = stars_list.T
# plt.scatter(im_y, im_x, facecolors='none', edgecolor='g')
# # Plot catalog stars
# plt.scatter(cat_y_array[cat_good_indices], cat_x_array[cat_good_indices], c='r', s=20, marker='+')
# plt.show()
# Match image and catalog stars
matched_indices = matchStars(stars_list, cat_x_array, cat_y_array,
cat_good_indices, match_radius)
# Skip this image is no stars were matched
if len(matched_indices) < config.min_matched_stars:
continue
matched_indices = np.array(matched_indices)
matched_img_inds, matched_cat_inds, dist_list = matched_indices.T
# Extract data from matched stars
matched_img_stars = stars_list[matched_img_inds.astype(np.int)]
matched_cat_stars = extracted_catalog[matched_cat_inds.astype(np.int)]
# Put the matched stars to a dictionary
matched_stars[jd] = [matched_img_stars, matched_cat_stars, dist_list]
# # Plot matched stars
# im_y, im_x, _, _ = matched_img_stars.T
# cat_y = cat_y_array[matched_cat_inds.astype(np.int)]
# cat_x = cat_x_array[matched_cat_inds.astype(np.int)]
# plt.scatter(im_x, im_y, c='r', s=5)
# plt.scatter(cat_x, cat_y, facecolors='none', edgecolor='g')
# plt.xlim([0, platepar.X_res])
# plt.ylim([platepar.Y_res, 0])
# plt.show()
# If residuals on the image should be computed
if not sky_coords:
unit_label = 'px'
# Extract all distances
global_dist_list = []
# level_list = []
# mag_list = []
for jd in matched_stars:
# matched_img_stars, matched_cat_stars, dist_list = matched_stars[jd]
_, _, dist_list = matched_stars[jd]
global_dist_list += dist_list.tolist()
# # TEST
# level_list += matched_img_stars[:, 3].tolist()
# mag_list += matched_cat_stars[:, 2].tolist()
# # Plot levels vs. magnitudes
# plt.scatter(mag_list, np.log10(level_list))
# plt.xlabel('Magnitude')
# plt.ylabel('Log10 level')
# plt.show()
# Compute the residuals on the sky
else:
unit_label = 'arcmin'
global_dist_list = []
# Go through all matched stars
for jd in matched_stars:
matched_img_stars, matched_cat_stars, dist_list = matched_stars[jd]
# Go through all stars on the image
for img_star_entry, cat_star_entry in zip(matched_img_stars,
matched_cat_stars):
# Extract star coords
star_y = img_star_entry[0]
star_x = img_star_entry[1]
cat_ra = cat_star_entry[0]
cat_dec = cat_star_entry[1]
# Convert image coordinates to RA/Dec
_, star_ra, star_dec, _ = xyToRaDecPP([jd2Date(jd)], [star_x], [star_y], [1], \
platepar, extinction_correction=False)
# Compute angular distance between the predicted and the catalog position
ang_dist = np.degrees(angularSeparation(np.radians(cat_ra), np.radians(cat_dec), \
np.radians(star_ra[0]), np.radians(star_dec[0])))
# Store the angular separation in arc minutes
global_dist_list.append(ang_dist * 60)
# Number of matched stars
n_matched = len(global_dist_list)
if n_matched == 0:
if verbose:
print(
'No matched stars with radius {:.1f} px!'.format(match_radius))
if ret_nmatch:
return 0, 9999.0, 9999.0, {}
else:
return 9999.0
# Calculate the average distance
avg_dist = np.median(global_dist_list)
cost = (avg_dist**2) * (1.0 / np.sqrt(n_matched + 1))
if verbose:
print()
print("Matched {:d} stars with radius of {:.1f} px".format(
n_matched, match_radius))
print(" Average distance = {:.3f} {:s}".format(
avg_dist, unit_label))
print(" Cost function = {:.5f}".format(cost))
if ret_nmatch:
return n_matched, avg_dist, cost, matched_stars
else:
return cost
def matchStarsResiduals(config,
platepar,
catalog_stars,
star_dict,
match_radius,
ret_nmatch=False):
""" Match the image and catalog stars with the given astrometry solution and estimate the residuals
between them.
Arguments:
config: [Config structure]
platepar: [Platepar structure] Astrometry parameters.
catalog_stars: [ndarray] An array of catalog stars (ra, dec, mag).
star_dict: [ndarray] A dictionary where the keys are JDs when the stars were recorded and values are
2D list of stars, each entry is (X, Y, bg_level, level).
match_radius: [float] Maximum radius for star matching (pixels).
min_matched_stars: [int] Minimum number of matched stars on the image for the image to be accepted.
Keyword arguments:
ret_nmatch: [bool] If True, the function returns the number of matched stars and the average
deviation. False by defualt.
Return:
cost: [float] The cost function which weights the number of matched stars and the average deviation.
"""
# Estimate the FOV radius
fov_w = platepar.X_res / platepar.F_scale
fov_h = platepar.Y_res / platepar.F_scale
fov_radius = np.sqrt((fov_w / 2)**2 + (fov_h / 2)**2)
# print('fscale', platepar.F_scale)
# print('FOV w:', fov_w)
# print('FOV h:', fov_h)
# print('FOV radius:', fov_radius)
# Dictionary containing the matched stars, the keys are JDs of every image
matched_stars = {}
# Go through every FF image and its stars
for jd in star_dict:
# Estimate RA,dec of the centre of the FOV
_, RA_c, dec_c, _ = XY2CorrectedRADecPP([jd2Date(jd)],
[platepar.X_res / 2],
[platepar.Y_res / 2], [0],
platepar)
RA_c = RA_c[0]
dec_c = dec_c[0]
# Get stars from the catalog around the defined center in a given radius
_, extracted_catalog = subsetCatalog(catalog_stars, RA_c, dec_c,
fov_radius,
config.catalog_mag_limit)
ra_catalog, dec_catalog, mag_catalog = extracted_catalog.T
# Extract stars for the given Julian date
stars_list = star_dict[jd]
stars_list = np.array(stars_list)
# Convert all catalog stars to image coordinates
cat_x_array, cat_y_array = raDecToCorrectedXYPP(
ra_catalog, dec_catalog, jd, platepar)
# Take only those stars which are within the FOV
x_indices = np.argwhere((cat_x_array >= 0)
& (cat_x_array < platepar.X_res))
y_indices = np.argwhere((cat_y_array >= 0)
& (cat_y_array < platepar.Y_res))
cat_good_indices = np.intersect1d(x_indices,
y_indices).astype(np.uint32)
# cat_x_array = cat_x_array[good_indices]
# cat_y_array = cat_y_array[good_indices]
# # Plot image stars
# im_y, im_x, _, _ = stars_list.T
# plt.scatter(im_y, im_x, facecolors='none', edgecolor='g')
# # Plot catalog stars
# plt.scatter(cat_y_array[cat_good_indices], cat_x_array[cat_good_indices], c='r', s=20, marker='+')
# plt.show()
# Match image and catalog stars
matched_indices = matchStars(stars_list, cat_x_array, cat_y_array,
cat_good_indices, match_radius)
# Skip this image is no stars were matched
if len(matched_indices) < config.min_matched_stars:
continue
matched_indices = np.array(matched_indices)
matched_img_inds, matched_cat_inds, dist_list = matched_indices.T
# Extract data from matched stars
matched_img_stars = stars_list[matched_img_inds.astype(np.int)]
matched_cat_stars = extracted_catalog[matched_cat_inds.astype(np.int)]
# Put the matched stars to a dictionary
matched_stars[jd] = [matched_img_stars, matched_cat_stars, dist_list]
# # Plot matched stars
# im_y, im_x, _, _ = matched_img_stars.T
# cat_y = cat_y_array[matched_cat_inds.astype(np.int)]
# cat_x = cat_x_array[matched_cat_inds.astype(np.int)]
# plt.scatter(im_x, im_y, c='r', s=5)
# plt.scatter(cat_x, cat_y, facecolors='none', edgecolor='g')
# plt.xlim([0, platepar.X_res])
# plt.ylim([platepar.Y_res, 0])
# plt.show()
# Extract all distances
global_dist_list = []
# level_list = []
# mag_list = []
for jd in matched_stars:
# matched_img_stars, matched_cat_stars, dist_list = matched_stars[jd]
_, _, dist_list = matched_stars[jd]
global_dist_list += dist_list.tolist()
# # TEST
# level_list += matched_img_stars[:, 3].tolist()
# mag_list += matched_cat_stars[:, 2].tolist()
# # Plot levels vs. magnitudes
# plt.scatter(mag_list, np.log10(level_list))
# plt.xlabel('Magnitude')
# plt.ylabel('Log10 level')
# plt.show()
# Number of matched stars
n_matched = len(global_dist_list)
if n_matched == 0:
if ret_nmatch:
return 0, 9999.0, 9999.0, {}
else:
return 9999.0
# Calculate the average distance
avg_dist = np.mean(global_dist_list)
cost = (avg_dist**2) * (1.0 / np.sqrt(n_matched + 1))
print('Matched {:d} stars with radius of {:.2f} px'.format(
n_matched, match_radius))
print('Avg dist', avg_dist)
print('Cost:', cost)
print('-----')
if ret_nmatch:
return n_matched, avg_dist, cost, matched_stars
else:
return cost