def test_consistency_with_horizons(use_DE440s, obstime):
# Check that the high-accuracy Astropy ephemeris has been set
assert solar_system_ephemeris.get() == 'de440s'
# Check whether the location of Earth is the same between Astropy and JPL HORIZONS
e1 = get_earth(obstime)
e2 = get_horizons_coord('Geocenter', obstime)
assert_quantity_allclose(e2.separation_3d(e1), 0 * u.km, atol=50 * u.m)
# Check whether the location of Mars is the same between Astropy and JPL HORIZONS
e1 = get_body_heliographic_stonyhurst('mars', obstime)
e2 = get_horizons_coord('Mars barycenter', obstime)
assert_quantity_allclose(e2.separation_3d(e1), 0 * u.km, atol=500 * u.m)
def test_get_horizons_coord_dict_time():
# get_horizons_coord() depends on astroquery
pytest.importorskip("astroquery")
time_dict = {'start': '2013-03-01', 'stop': '2013-03-03', 'step': '1d'}
time_ref = Time(['2013-03-01', '2013-03-02', '2013-03-03'])
e = get_horizons_coord('Geocenter', time_dict)
e_ref = get_horizons_coord('Geocenter', time_ref)
assert_quantity_allclose(e.lon, e_ref.lon, atol=1e-9 * u.deg)
assert_quantity_allclose(e.lat, e_ref.lat)
assert_quantity_allclose(e.radius, e_ref.radius)
def test_consistency_with_horizons(astropy_ephemeris_de432s, obstime):
# get_horizons_coord() depends on astroquery
pytest.importorskip("astroquery")
# Check whether the location of Earth is the same between Astropy and JPL HORIZONS
e1 = get_earth(obstime)
e2 = get_horizons_coord('Geocenter', obstime)
assert_quantity_allclose(e2.separation_3d(e1), 0 * u.km, atol=50 * u.m)
# Check whether the location of Mars is the same between Astropy and JPL HORIZONS
e1 = get_body_heliographic_stonyhurst('mars', obstime)
e2 = get_horizons_coord('Mars barycenter', obstime)
assert_quantity_allclose(e2.separation_3d(e1), 0 * u.km, atol=500 * u.m)
def test_get_horizons_coord():
# get_horizons_coord() depends on astroquery
pytest.importorskip("astroquery")
# Validate against published values from the Astronomical Almanac (2013)
e1 = get_horizons_coord('Geocenter', '2013-Jan-01')
assert_quantity_allclose(e1.lon, 0 * u.deg, atol=5e-6 * u.deg)
assert_quantity_allclose(e1.lat, -3.03 * u.deg, atol=5e-3 * u.deg)
assert_quantity_allclose(e1.radius, 0.9832947 * u.AU, atol=5e-7 * u.AU)
e2 = get_horizons_coord('Geocenter', '2013-Sep-01')
assert_quantity_allclose(e1.lon, 0 * u.deg, atol=5e-6 * u.deg)
assert_quantity_allclose(e2.lat, 7.19 * u.deg, atol=5e-3 * u.deg)
assert_quantity_allclose(e2.radius, 1.0092561 * u.AU, atol=5e-7 * u.AU)
def get_position_heliographic_stonyhurst(body_name, time, observer):
"""
Get the position of one of the supported bodies as seen from the
observer. If
Parameters
----------
body_name :
time :
observer :
Returns
-------
`~astropy.coordinate.SkyCoord`
"""
_body_name = body_name.lower()
# Check if the body is one of the supported spacecraft. Note that the
if _body_name in spacecraft:
coordinate = get_horizons_coord(_body_name, time).transform_to(
frames.HeliographicStonyhurst)
# Check if the body is one of the supported solar system objects
elif _body_name in solar_system_objects:
coordinate = get_body_heliographic_stonyhurst(_body_name,
time=time,
observer=observer)
else:
raise ValueError('The body name is not recognized.')
return coordinate
def eitprep(fitsfile, return_map=False):
hdul = fits.open(fitsfile)
hdul[0].verify('silentfix')
header = hdul[0].header
data = hdul[0].data.astype(np.float64)
new_coords = get_horizons_coord(header['TELESCOP'], parse_time(header['DATE_OBS']))
header['HGLN_OBS'] = new_coords.lon.to('deg').value
header['HGLT_OBS'] = new_coords.lat.to('deg').value
header['DSUN_OBS'] = new_coords.radius.to('m').value
header.pop('hec_x')
header.pop('hec_y')
header.pop('hec_z')
# Target scale is 2.63 arcsec/px
target_scale = 2.63
scale_factor = header['CDELT1'] / target_scale
# Center of rotation at reference pixel converted to a coordinate origin at 0
reference_pixel = [header['CRPIX1'] - 1, header['CRPIX2'] - 1]
# Rotation angle with openCV uses coordinate origin at top-left corner. For solar images in numpy we need to invert the angle.
angle = -header['SC_ROLL']
# Run scaled rotation. The output will be a rotated, rescaled, padded array.
prepdata = scale_rotate(data, angle=angle, scale_factor=scale_factor, reference_pixel=reference_pixel)
prepdata[prepdata < 0] = 0
prepdata[np.isnan(prepdata)] = 0
if return_map:
prepdata = Map(prepdata, header)
return prepdata
def test_get_horizons_coord_array_time():
# get_horizons_coord() depends on astroquery
pytest.importorskip("astroquery")
# Validate against published values from the Astronomical Almanac (2013, C8-C13)
array_time = Time(['2013-05-01', '2013-06-01', '2013-04-01', '2013-03-01'])
e = get_horizons_coord('Geocenter', array_time)
assert_quantity_allclose(e[0].lon, 0 * u.deg, atol=5e-6 * u.deg)
assert_quantity_allclose(e[0].lat, -4.17 * u.deg, atol=5e-3 * u.deg)
assert_quantity_allclose(e[0].radius, 1.0075271 * u.AU, atol=5e-7 * u.AU)
assert_quantity_allclose(e[1].lon, 0 * u.deg, atol=5e-6 * u.deg)
assert_quantity_allclose(e[1].lat, -0.66 * u.deg, atol=5e-3 * u.deg)
assert_quantity_allclose(e[1].radius, 1.0140013 * u.AU, atol=5e-7 * u.AU)
assert_quantity_allclose(e[2].lon, 0 * u.deg, atol=5e-6 * u.deg)
assert_quantity_allclose(e[2].lat, -6.54 * u.deg, atol=5e-3 * u.deg)
assert_quantity_allclose(e[2].radius, 0.9992311 * u.AU, atol=5e-7 * u.AU)
assert_quantity_allclose(e[3].lon, 0 * u.deg, atol=5e-6 * u.deg)
assert_quantity_allclose(e[3].lat, -7.22 * u.deg, atol=5e-3 * u.deg)
assert_quantity_allclose(e[3].radius, 0.9908173 * u.AU, atol=5e-7 * u.AU)
def get_position(body_name, time):
"""
Get the position of the body in space.
Parameters
----------
body_name :
time :
Returns
-------
`~astropy.coordinate.SkyCoord`
"""
_body_name = body_name.lower()
# Check if the body is one of the supported spacecraft
if _body_name in spacecraft:
coordinate = get_horizons_coord(_body_name, time)
elif _body_name in solar_system_objects:
coordinate = get_body(_body_name, time=time)
else:
raise ValueError('The body name is not recognized.')
return coordinate
's',
color='white',
fillstyle='none',
markersize=12,
label='Mercury')
lasco.plot(axes=ax)
plt.show()
###############################################################################
# SOHO is actually a `halo orbit <https://en.wikipedia.org/wiki/Solar_and_Heliospheric_Observatory#Orbit>`__
# around the Sun–Earth L1 point, about 1 million km away from the Earth.
# The following functions queries JPL HORIZONS which includes positions of major spacecraft.
# This function requires an internet connection to fetch the ephemeris data.
soho = get_horizons_coord('SOHO', lasco.date)
###############################################################################
# For fun, let's see how far away from the Earth SOHO is by converting to
# an Earth-centered coordinate system (GCRS).
print(soho.transform_to('gcrs').distance.to('km'))
###############################################################################
# Let's fix the header.
lasco.meta['HGLN_OBS'] = soho.lon.to('deg').value
lasco.meta['HGLT_OBS'] = soho.lat.to('deg').value
lasco.meta['DSUN_OBS'] = soho.radius.to('m').value
###############################################################################
