def _get_illum_angles(self):
"Ilumin returns (trgepoch, srfvec, phase, solar, emission)"
if self.obs is not None:
output = spice.ilumin("Ellipsoid", self.target, self.et, self.ref_frame, self.corr, self.obs, self.spoint)
return IllumAngles.fromtuple(output[2:])
else:
solar = spice.vsep(self.sun_direction, self.snormal)
# leaving at 0 what I don't have
return IllumAngles.fromtuple((0, solar, 0))
def illum_angles(self):
"""Ilumin returns (trgepoch, srfvec, phase, solar, emission)
"""
if self.obs is not None:
output = spice.ilumin(
"Ellipsoid",
self.target,
self.et,
self.ref_frame,
self.corr,
self.obs,
self.spoint,
)
return IllumAngles.fromtuple(output[2:])
else:
solar = spice.vsep(self.sun_direction, self.snormal)
# leaving at 0 what I don't have
return IllumAngles.fromtuple((0, solar, 0))
def highres_swath_geometry(self, hdul, map_data, res=200):
"""
Generates an artificial high-resolution slit, calculates viewing geometry and surface-intercept map.
Parameters
----------
hdul : HDUList
Opened FITS file.
res : int, optional
The desired number of artificial elements along the slit. Defaults to 200.
Returns
-------
latitude : array
Array of latitudes for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't intercept
the surface of Mars.
longitude : array
Array of longitudes for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't intercept
the surface of Mars.
sza : array
Array of solar zenith angles for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't
intercept the surface of Mars.
ea
pa
local_time : array
Array of local times for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't intercept
the surface of Mars.
x : array
Horizontal coordinate edges in angular space. Has shape (n+1, m+1) for geometry arrays with shape (n,m).
y : array
Vertical coordinate edges in angular space. Has shape (n+1, m+1) for geometry arrays with shape (n,m).
cx : array
Horizontal coordinate centers in angular space. Same shape as geometry arrays.
cy : array
Vertical coordinate centers in angular space. Same shape as geometry arrays.
context_map : array
High-resolution image of the Mars surface as intercepted by the swath. RGB tuples with shape (n,m,3).
"""
# get swath vectors, ephemeris times, and mirror angles
vec = hdul['pixelgeometry'].data['pixel_vec']
et = hdul['integration'].data['et']
# get dimensions of the input data
n_int = hdul['integration'].data.shape[0]
n_spa = len(hdul['binning'].data['spapixlo'][0])
# set the high-resolution slit width and calculate the number of high-resolution integrations
hifi_spa = res
hifi_int = int(hifi_spa / n_spa * n_int)
# make arrays of ephemeris time and array to hold the new swath vector calculations
# here thru 481 just interpolate et_arr and vec_arr onto new grid (int, pos) and (int, pos, 3) adn they're all just center values
et_arr = np.expand_dims(et, 1) * np.ones((n_int, n_spa))
et_arr = resize(et_arr, (hifi_int, hifi_spa), mode='edge')
vec_arr = np.zeros((hifi_int + 1, hifi_spa + 1, 3))
# make an artificially-divided swath and create new array of swath vectors
if self.__flip:
lower_left = vec[0, :, 0, 0]
upper_left = vec[-1, :, 0, 1]
lower_right = vec[0, :, -1, 2]
upper_right = vec[-1, :, -1, 3]
else:
lower_left = vec[0, :, 0, 1]
upper_left = vec[-1, :, 0, 0]
lower_right = vec[0, :, -1, 3]
upper_right = vec[-1, :, -1, 2]
for e in range(3):
a = np.linspace(lower_left[e], upper_left[e], hifi_int + 1)
b = np.linspace(lower_right[e], upper_right[e], hifi_int + 1)
vec_arr[:, :, e] = np.array(
[np.linspace(i, j, hifi_spa + 1) for i, j in zip(a, b)])
# resize array to extract centers
vec_arr = resize(vec_arr, (hifi_int, hifi_spa, 3), anti_aliasing=True)
# make empty arrays to hold geometry calculations
latitude = np.zeros((hifi_int, hifi_spa)) * np.nan
longitude = np.zeros((hifi_int, hifi_spa)) * np.nan
sza = np.zeros((hifi_int, hifi_spa)) * np.nan
phase_angle = np.zeros((hifi_int, hifi_spa)) * np.nan
emission_angle = np.zeros((hifi_int, hifi_spa)) * np.nan
local_time = np.zeros((hifi_int, hifi_spa)) * np.nan
context_map = np.zeros((hifi_int, hifi_spa, 4)) * np.nan
# calculate intercept latitude and longitude using SPICE, looping through each high-resolution pixel
target = 'Mars'
frame = 'IAU_Mars'
abcorr = 'LT+S'
observer = 'MAVEN'
body = 499 # Mars IAU code
for i in range(hifi_int):
for j in range(hifi_spa):
et = et_arr[i, j]
los_mid = vec_arr[i, j, :]
# try to perform the SPICE calculations and record the results
try:
# calculate surface intercept
spoint, trgepc, srfvec = spice.sincpt(
'Ellipsoid', target, et, frame, abcorr, observer,
frame, los_mid)
# calculate illumination angles
trgepc, srfvec, phase_for, solar, emissn = spice.ilumin(
'Ellipsoid', target, et, frame, abcorr, observer,
spoint)
# convert from rectangular to spherical coordinates
rpoint, colatpoint, lonpoint = spice.recsph(spoint)
# convert longitude from domain [-pi,pi) to [0,2pi)
if lonpoint < 0.:
lonpoint += 2 * np.pi
# convert ephemeris time to local solar time
hr, mn, sc, time, ampm = spice.et2lst(et,
body,
lonpoint,
'planetocentric',
timlen=256,
ampmlen=256)
# convert spherical coordinates to latitude and longitude in degrees
latitude[i, j] = np.degrees(np.pi / 2 - colatpoint)
longitude[i, j] = np.degrees(lonpoint)
# convert illumination angles to degrees and record
sza[i, j] = np.degrees(solar)
phase_angle[i, j] = np.degrees(phase_for)
emission_angle[i, j] = np.degrees(emissn)
# convert local solar time to decimal hour
local_time[i, j] = hr + mn / 60 + sc / 3600
# convert latitude and longitude to pixel coordinates
map_lat = int(np.round(np.degrees(colatpoint), 1) * 10)
map_lon = int(np.round(np.degrees(lonpoint), 1) * 10)
# make a corresponding magnetic field topology map
context_map[i, j] = map_data[map_lat, map_lon]
# if the SPICE calculation fails, this (probably) means it didn't intercept the planet
except:
# This pixel (or the vector) didn't intercept the planet
pass
# get mirror angles
angles = hdul['integration'].data[
'mirror_deg'] * 2 # convert from mirror angles to FOV angles
dang = np.diff(angles)[0]
# create an meshgrid of angular coordinates for the high-resolution pixel edges
x, y = np.meshgrid(
np.linspace(0, self.__slit_width, hifi_spa + 1),
np.linspace(angles[0] - dang / 2, angles[-1] + dang / 2,
hifi_int + 1))
# calculate the angular separation between pixels
dslit = self.__slit_width / hifi_spa
# create an meshgrid of angular coordinates for the high-resolution pixel centers
cx, cy = np.meshgrid(
np.linspace(0 + dslit, self.__slit_width - dslit, hifi_spa),
np.linspace(angles[0], angles[-1], hifi_int))
# beta-flip the coordinate arrays if necessary
if self.__flip:
x = np.fliplr(x)
y = (np.fliplr(y) - 90) / (-1) + 90
cx = np.fliplr(cx)
cy = (np.fliplr(cy) - 90) / (-1) + 90
# convert longitude to [-180,180)
longitude[np.where(longitude > 180)] -= 360
# return the geometry and coordinate arrays
# cx, cy is for a lat/lon grid on top of the map (50, 1) --> (200, 4)
# all but x, y, context_map is (n_integrations, n_positions)
# the context map has shape (n_integrations, n_positions, 4)
# x, y, cx, cy are (n_int +1, n_pos + 1)
return latitude, longitude, sza, emission_angle, phase_angle, \
local_time, x, y, cx, cy, context_map
])
nadir_lonlats = np.asfarray(
[sp.reclat(mars2tgo)
for mars2tgo in list(mars2tgo_pos)])[:, 1:3] * sp.dpr()
nadir_lsts = [
sp.et2lst(time, 499, (nadir_lonlat[0] / sp.dpr()),
"PLANETOCENTRIC")[3]
for time, nadir_lonlat in zip(list(times), list(nadir_lonlats))
]
nadir_lsts_hours = np.asfarray([
np.float(nadir_lst[0:2]) + np.float(nadir_lst[3:5]) / 60.0 +
np.float(nadir_lst[6:8]) / 3600.0 for nadir_lst in nadir_lsts
])
nadir_incidence_angles = np.asfarray([
sp.ilumin(shape, target, time, "IAU_MARS", abcorr, observer,
mars2tgo)[3] * sp.dpr()
for time, mars2tgo in zip(list(times), list(mars2tgo_pos))
])
print("Calculating altitudes")
#calculate tangent point altitude
altitudes = np.asfarray([
sp.npedln(mars_axes[0], mars_axes[1], mars_axes[2], line_point,
line_vector)[1] for line_point, line_vector in zip(
list(line_points), list(line_vectors))
])
print("Checking if occultations real or not")
#check that tgo is really behind mars as seen from sun: calculate angle between tgo-sun vector and tgo-mars centre vector
sep_angles = np.asfarray([
sp.vsep(sp.vsub(line_coord, line_point), line_vector)
method = "Ellipsoid"
target = "MARS"
fixref = "IAU_MARS"
abcorr = "None"
obsrvr = "SUN"
spoint = sp.latrec(3390, -24.6 / sp.dpr(), 18.3 / sp.dpr())
et = sp.utc2et("2003 OCT 28, 00:00:00")
step = 60
for loop in range(100):
time = et + step * loop
time_string = sp.et2utc(time, "C", 0)
sza = sp.ilumin(method, target, time, fixref, abcorr, obsrvr,
spoint)[3] * sp.dpr()
def writeLog(file_name, lines_to_write):
"""function to append log file"""
# global LOG_PATHS
logFile = open(file_name + ".csv", 'w')
for line_to_write in lines_to_write:
logFile.write(line_to_write + '\n')
logFile.close()
# print(line_to_write)
utcstring_start = '2016 MAR 17 12:00:00'
utcstring_end = '2017 JAN 17 12:00:00'
def get_sol_incidence(date, r):
et = spice.str2et(str(date))
_, _, _, sol_incidence, _ = spice.ilumin('ellipsoid', 'moon', et,
'iau_moon', 'lt+s', 'sun', r)
return np.degrees(sol_incidence)
def highres_swath_geometry(hdul, res=200, twilight='discrete'):
"""
Generates an artificial high-resolution slit, calculates viewing geometry and surface-intercept map.
Parameters
----------
hdul : HDUList
Opened FITS file.
res : int, optional
The desired number of artificial elements along the slit. Defaults to 200.
twilight : str
The appearance of the twilight zone. 'discrete' has a partially transparent zone with sharp edges while
'continuous' smoothes it with a cosine function. The discrete option does not always work on all systems, but
I cannot yet say why that is. In those cases you get the continuous appearance.
Returns
-------
latitude : array
Array of latitudes for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't intercept
the surface of Mars.
longitude : array
Array of longitudes for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't intercept
the surface of Mars.
sza : array
Array of solar zenith angles for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't
intercept the surface of Mars.
local_time : array
Array of local times for the centers of each high-resolution artificial pixel. NaNs if pixel doesn't intercept
the surface of Mars.
x : array
Horizontal coordinate edges in angular space. Has shape (n+1, m+1) for geometry arrays with shape (n,m).
y : array
Vertical coordinate edges in angular space. Has shape (n+1, m+1) for geometry arrays with shape (n,m).
cx : array
Horizontal coordinate centers in angular space. Same shape as geometry arrays.
cy : array
Vertical coordinate centers in angular space. Same shape as geometry arrays.
context_map : array
High-resolution image of the Mars surface as intercepted by the swath. RGB tuples with shape (n,m,3).
"""
# calculate beta-flip state
flipped = beta_flip(hdul)
# get swath vectors, ephemeris times, and mirror angles
vec = hdul['pixelgeometry'].data['pixel_vec']
et = hdul['integration'].data['et']
# get dimensions of the input data
n_int = hdul['integration'].data.shape[0]
n_spa = len(hdul['binning'].data['spapixlo'][0])
# set the high-resolution slit width and calculate the number of high-resolution integrations
hifi_spa = res
hifi_int = int(hifi_spa / n_spa * n_int)
# make arrays of ephemeris time and array to hold the new swath vector calculations
et_arr = np.expand_dims(et, 1) * np.ones((n_int, n_spa))
et_arr = resize(et_arr, (hifi_int, hifi_spa), mode='edge')
vec_arr = np.zeros((hifi_int + 1, hifi_spa + 1, 3))
# make an artificially-divided slit and create new array of swath vectors
if flipped:
lower_left = vec[0, :, 0, 0]
upper_left = vec[-1, :, 0, 1]
lower_right = vec[0, :, -1, 2]
upper_right = vec[-1, :, -1, 3]
else:
lower_left = vec[0, :, 0, 1]
upper_left = vec[-1, :, 0, 0]
lower_right = vec[0, :, -1, 3]
upper_right = vec[-1, :, -1, 2]
for e in range(3):
a = np.linspace(lower_left[e], upper_left[e], hifi_int + 1)
b = np.linspace(lower_right[e], upper_right[e], hifi_int + 1)
vec_arr[:, :, e] = np.array([np.linspace(i, j, hifi_spa + 1) for i, j in zip(a, b)])
# resize array to extract centers
vec_arr = resize(vec_arr, (hifi_int, hifi_spa, 3), anti_aliasing=True)
# make empty arrays to hold geometry calculations
latitude = np.zeros((hifi_int, hifi_spa))*np.nan
longitude = np.zeros((hifi_int, hifi_spa))*np.nan
sza = np.zeros((hifi_int, hifi_spa))*np.nan
phase_angle = np.zeros((hifi_int, hifi_spa))*np.nan
emission_angle = np.zeros((hifi_int, hifi_spa))*np.nan
local_time = np.zeros((hifi_int, hifi_spa))*np.nan
context_map = np.zeros((hifi_int, hifi_spa, 3))*np.nan
# load Mars surface map and switch longitude domain from [-180,180) to [0, 360)
mars_surface_map = plt.imread(os.path.join(pkg_resources.resource_filename('maven_iuvs', 'ancillary/'),
'mars_surface_map.jpg'))
offset_map = np.zeros_like(mars_surface_map)
offset_map[:, :1800, :] = mars_surface_map[:, 1800:, :]
offset_map[:, 1800:, :] = mars_surface_map[:, :1800, :]
mars_surface_map = offset_map
# calculate intercept latitude and longitude using SPICE, looping through each high-resolution pixel
target = 'Mars'
frame = 'IAU_Mars'
abcorr = 'LT+S'
observer = 'MAVEN'
body = 499 # Mars IAU code
for i in range(hifi_int):
for j in range(hifi_spa):
et = et_arr[i, j]
los_mid = vec_arr[i, j, :]
# try to perform the SPICE calculations and record the results
# noinspection PyBroadException
try:
# calculate surface intercept
spoint, trgepc, srfvec = spice.sincpt('Ellipsoid', target, et, frame, abcorr, observer, frame, los_mid)
# calculate illumination angles
trgepc, srfvec, phase_for, solar, emissn = spice.ilumin('Ellipsoid', target, et, frame, abcorr,
observer, spoint)
# convert from rectangular to spherical coordinates
rpoint, colatpoint, lonpoint = spice.recsph(spoint)
# convert longitude from domain [-pi,pi) to [0,2pi)
if lonpoint < 0.:
lonpoint += 2 * np.pi
# convert ephemeris time to local solar time
hr, mn, sc, time, ampm = spice.et2lst(et, body, lonpoint, 'planetocentric', timlen=256, ampmlen=256)
# convert spherical coordinates to latitude and longitude in degrees
latitude[i, j] = np.degrees(np.pi / 2 - colatpoint)
longitude[i, j] = np.degrees(lonpoint)
# convert illumination angles to degrees and record
sza[i, j] = np.degrees(solar)
phase_angle[i, j] = np.degrees(phase_for)
emission_angle[i, j] = np.degrees(emissn)
# convert local solar time to decimal hour
local_time[i, j] = hr + mn / 60 + sc / 3600
# convert latitude and longitude to pixel coordinates
map_lat = int(np.round(np.degrees(colatpoint), 1) * 10)
map_lon = int(np.round(np.degrees(lonpoint), 1) * 10)
# instead of changing an alpha layer, I just multiply an RGB triplet by a scaling fraction in order to
# make it darker; determine that scalar here based on solar zenith angle
if twilight == 'discrete':
if (sza[i, j] > 90) & (sza[i, j] <= 102):
twilight = 0.7
elif sza[i, j] > 102:
twilight = 0.4
else:
twilight = 1
else:
if (sza[i, j] > 90) & (sza[i, j] <= 102):
tsza = (sza[i, j]-90)*np.pi/2/12
twilight = np.cos(tsza)*0.6 + 0.4
elif sza[i, j] > 102:
twilight = 0.4
else:
twilight = 1
# place the corresponding pixel from the high-resolution Mars map into the swath context map with the
# twilight scaling
context_map[i, j, :] = mars_surface_map[map_lat, map_lon, :] / 255 * twilight
# if the SPICE calculation fails, this (probably) means it didn't intercept the planet
except:
pass
# get mirror angles
angles = hdul['integration'].data['mirror_deg'] * 2 # convert from mirror angles to FOV angles
dang = np.diff(angles)[0]
# create an meshgrid of angular coordinates for the high-resolution pixel edges
x, y = np.meshgrid(np.linspace(0, slit_width_deg, hifi_spa + 1),
np.linspace(angles[0] - dang / 2, angles[-1] + dang / 2, hifi_int + 1))
# calculate the angular separation between pixels
dslit = slit_width_deg / hifi_spa
# create an meshgrid of angular coordinates for the high-resolution pixel centers
cx, cy = np.meshgrid(
np.linspace(0 + dslit, slit_width_deg - dslit, hifi_spa),
np.linspace(angles[0], angles[-1], hifi_int))
# beta-flip the coordinate arrays if necessary
if flipped:
x = np.fliplr(x)
y = (np.fliplr(y) - 90) / (-1) + 90
cx = np.fliplr(cx)
cy = (np.fliplr(cy) - 90) / (-1) + 90
# convert longitude to [-180,180)
longitude[np.where(longitude > 180)] -= 360
# return the geometry and coordinate arrays
return latitude, longitude, sza, local_time, x, y, cx, cy, context_map
def __compute_illumination_angles(self, et, spoint):
return spice.ilumin(
self.__method, self.__target, et, self.__frame, self.__abcorr,
self.__observer, spoint)
def project(self, get_illum=True, use_full_image=False):
'''
retrieve the planetographic coordinates of the center
of each pixel in the image
Parameters
----------
get_illum : bool
flag to also retrieve illumination angles (incidence,
emission and phase), and get a Lambertian correction
[default: True]
use_full_image : bool
flag to process the full image, or use a bounding box
of 1.2*(planetary radius) around the center to speed up
computation. Turn off if bounding box produces errors.
[default: False]
'''
if not use_full_image:
maxsize = np.max([self.obsa, self.obsb])*self.platecal.scale
xstart, ystart = np.asarray(self.R2P0 - 1.2*maxsize, dtype=int)
xend, yend = np.asarray(self.R2P0 + 1.2*maxsize, dtype=int)
xstart = max([xstart, 0])
ystart = max([ystart, 0])
xend = min([xend, self.nx])
yend = min([yend, self.ny])
else:
xstart = 0
xend = self.nx
ystart = 0
yend = self.ny
## create the empty arrays to hold the values
imgshape = self.img.shape[:2]
self.lat = -1000.*np.ones(imgshape)
self.lon = -1000.*np.ones(imgshape)
if get_illum:
self.incidence = np.zeros(imgshape)
self.emission = np.zeros(imgshape)
self.phase = np.zeros(imgshape)
self.solar_corr = np.zeros(imgshape)
for j in range(ystart, yend):
if(j%10 == 0):
print("\r %3d/%3d"%(j, yend), end='')
for i in range(xstart, xend):
## find the vector that refers to this pixel
pix = np.array([i,j], dtype=float)
RADeci = self.pix2radec(pix)
veci = spiceypy.radrec(1., RADeci[0], RADeci[1])
## check for the intercept
try:
spoint, ep, srfvec = \
spiceypy.sincpt(\
"Ellipsoid", self.target, self.et,\
self.target_frame, "CN", "EARTH",\
"J2000", veci)
except Exception as e:
continue
## if the intercept works, determine the planetographic
## lat/lon values
loni, lati, alt = \
spiceypy.recpgr(self.target, spoint, \
self.radii[0], self.flattening)
self.lat[j,i] = np.degrees(lati)
self.lon[j,i] = np.degrees(loni)
if get_illum:
_, _, phasei, inci, emissi = \
spiceypy.ilumin("Ellipsoid", self.target, \
self.et, self.target_frame, "CN",\
"EARTH", spoint)
## apply Lambertian correction
mu = np.cos(emissi); mu0 = np.cos(inci)
self.solar_corr[j,i] = 1./mu0
## save the
self.phase[j,i] = phasei
self.incidence[j,i] = inci
self.emission[j,i] = emissi
img = self.img.copy()
if get_illum:
if(len(img.shape) > 2):
for i in range(img.shape[2]):
img[:,:,i] *= self.solar_corr
## plot them out
fig = plt.figure(figsize=(8,15))
ax1 = fig.add_subplot(311)
ax2 = fig.add_subplot(312)
ax3 = fig.add_subplot(313)
ax1.imshow(self.lon, vmin=0., vmax=360.)
ax1.contour(self.lon, np.arange(0., 360., 15.), colors='k')
ax2.imshow(self.lat, vmin=-90., vmax=90.)
ax2.contour(self.lat, np.arange(-90, 90., 15.), colors='k')
ax3.imshow(img)
ax3.contour(self.lon, np.arange(0., 360., 30.), colors='k', linewidths=0.5)
ax3.contour(self.lat, np.arange(-90, 90., 30.), colors='k', linewidths=0.5)
ax1.set_title("Longitude")
ax2.set_title("Latitude")
plt.tight_layout()
plt.show()
# Pluto-Charon angle
vec_psurf_charon = vec_pluto_charon - vec_pluto_psurf
ang = sp.vsep(vec_psurf_charon, vec_pluto_psurf)
ang_pluto_charon[j, i] = ang
# Pluto-SC angle
vec_psurf_sc = vec_pluto_sc - vec_pluto_psurf
ang = sp.vsep(vec_psurf_sc, vec_pluto_psurf)
ang_pluto_sc[j, i] = ang
# Now, do this all a second way, just to validate.
(trgepc, srfvec, phase, solar,
emmisn) = sp.ilumin('ELLIPSOID', 'PLUTO', et, 'IAU_PLUTO', abcorr,
'Charon', vec_pluto_psurf_iau)
ang_pluto_sun_2[
j,
i] = solar # Solar incidence angle, from normal, at point. THIS MATCHES -- GOOD!
ang_pluto_charon_2[
j,
i] = emmisn # Angle from surface normal, to observer. 0 .. pi. THIS MATCHES
(trgepc, srfvec, phase, solar,
emmisn) = sp.ilumin('ELLIPSOID', 'PLUTO', et, 'IAU_PLUTO', abcorr,
'New Horizons', vec_pluto_psurf_iau)
ang_pluto_sc_2[
j,
i] = emmisn # Angle from surface normal, to observer. 0 .. pi. THIS MATCHES
def _get_srfvec(self):
if self.obs is None:
raise ObserverNotSetError
else:
output = spice.ilumin("Ellipsoid", self.target, self.et, self.ref_frame, self.corr, self.obs, self.spoint)
return output[1]
