def nearest_moon(dt, target='CASSINI'):
"""
:param dt:
:param target:
:return:
"""
et = spice.datetime2et(dt)
moondict = {}
NAIFIDS = range(601, 654, 1)
for x in NAIFIDS:
moon = spice.bodc2s(x)
frame = 'IAU_' + moon.upper()
observ = moon.upper()
corrtn = 'NONE'
state, ltime = spice.spkpos(target, et, frame, corrtn, observ)
# TODO do full calculation of altitude
lon, lat, alt = spice.recpgr(
moon.upper(), state,
spice.bodvrd(moon.upper(), 'RADII', 3)[1][0], 2.64e-4)
moondict[moon] = alt
sorteddict = OrderedDict(sorted(moondict.items(), key=lambda t: t[1]))
return sorteddict
def cassini_titan_altlatlon(tempdatetime):
et = spice.datetime2et(tempdatetime)
state, ltime = spice.spkezr('CASSINI', et, 'IAU_TITAN', 'NONE', 'TITAN')
lon, lat, alt = spice.recpgr('TITAN', state[:3], spice.bodvrd('TITAN', 'RADII', 3)[1][0], 2.64e-4)
return alt, lat * spice.dpr(), lon * spice.dpr()
def find_sub_pt(self):
'''
Finds the sub-observer point in the IAU_[target] frame
and also the in the J2000 frame as seen from Earth.
Also creates a vector from Earth to the sub-obs point in the
J2000 frame for future use.
'''
## get the position of the sub-obs point in the J2000 frame
self.subptvec, self.subptep, self.subpntobsvec = \
spiceypy.subpnt('INTERCEPT/ELLIPSOID', self.target, \
self.et, self.target_frame, 'CN', 'EARTH')
## convert to lat/lon
self.subptlon, self.subptlat, _ = \
spiceypy.recpgr(self.target, self.subptvec, \
self.radii[0], self.flattening)
## convert the line of sight vector to J2000
px1 = spiceypy.pxfrm2(self.target_frame, 'J2000', \
self.subptep, self.et)
self.subptJ2000 = np.matmul(px1, self.subpntobsvec)
## get the RA/DEC of the sub-obs point
self.subRA, self.subDec = spiceypy.recrad(self.subptJ2000)[1:]
self.RADec0 = np.array([self.subRA, self.subDec])
def cassini_altlatlon(utc, target='TITAN', output=False):
state = cassini_phase(utc)
lon, lat, alt = spice.recpgr(target, state[:3],
spice.bodvrd(target, 'RADII', 3)[1][0],
2.64e-4)
if output:
print("ALtitude", alt)
print("Latitude", lat * spice.dpr())
print("Longtitude", lon * spice.dpr())
return alt, lat * spice.dpr(), lon * spice.dpr()
def cassini_altitude(dt, moon, target='CASSINI'):
"""
:param dt:
:param moon:
:param target:
:return:
"""
et = spice.datetime2et(dt)
frame = 'IAU_' + moon.upper()
observ = moon.upper()
corrtn = 'NONE'
state, ltime = spice.spkpos(target, et, frame, corrtn, observ)
# TODO do full calculation of altitude
lon, lat, alt = spice.recpgr(moon.upper(), state,
spice.bodvrd(moon.upper(), 'RADII', 3)[1][0],
2.64e-4)
return alt
def bodyHA(body,et,qlon):
import spiceypy as sp
# SUB POINT POSITION
pos=sp.subpnt("Intercept: ellipsoid",
"EARTH",et,"IAU_EARTH","NONE",
body)
lpos=sp.recpgr("EARTH",pos[0],REARTH,FEARTH);
# LATITUDE AND LONGITUDE
lon=lpos[0]*RAD
lat=lpos[1]*RAD
# print d2s(lon),d2s(lat)
# DIFFERENCE IN LONGITUDE
dlon=numpy.mod(qlon-lon,360)
# HOUR ANGLE
# H = LST - ALPHA
ha=dlon
return ha
def f(p):
return spiceypy.recpgr(body, p, r, e)
def __Geometry(self, boresight=''):
#if self.geometry_flag is True and \
# self.time.window.all() == self.previous_tw.all():
# return
distance = []
altitude = []
boresight_latitude = []
boresight_longitude = []
latitude = []
longitude = []
subpoint_xyz = []
subpoint_pgc = []
subpoint_pcc = []
zaxis_target_angle = []
myaxis_target_angle = []
yaxis_target_angle = []
xaxis_target_angle = []
beta_angle = []
qs, qx, qy, qz = [], [], [] ,[]
x, y, z = [],[],[]
tar = self.target
time = self.time
for et in time.window:
try:
#
# Compute the distance
#
ptarg, lt = spiceypy.spkpos(tar.name, et, tar.frame, time.abcorr,
self.name)
x.append(ptarg[0])
y.append(ptarg[1])
z.append(ptarg[2])
vout, vmag = spiceypy.unorm(ptarg)
distance.append(vmag)
#
# Compute the geometric sub-observer point.
#
if tar.frame == 'MARSIAU':
tar_frame = 'IAU_MARS'
else:
tar_frame = tar.frame
spoint, trgepc, srfvec = spiceypy.subpnt(tar.method, tar.name, et,
tar_frame, time.abcorr,
self.name)
subpoint_xyz.append(spoint)
#
# Compute the observer's altitude from SPOINT.
#
dist = spiceypy.vnorm(srfvec)
altitude.append(dist)
#
# Convert the sub-observer point's rectangular coordinates to
# planetographic longitude, latitude and altitude.
#
spglon, spglat, spgalt = spiceypy.recpgr(tar.name, spoint,
tar.radii_equ, tar.flat)
#
# Convert radians to degrees.
#
spglon *= spiceypy.dpr()
spglat *= spiceypy.dpr()
subpoint_pgc.append([spglon, spglat, spgalt])
#
# Convert sub-observer point's rectangular coordinates to
# planetocentric radius, longitude, and latitude.
#
spcrad, spclon, spclat = spiceypy.reclat(spoint)
#
# Convert radians to degrees.
#
spclon *= spiceypy.dpr()
spclat *= spiceypy.dpr()
subpoint_pcc.append([spclon, spclat, spcrad])
latitude.append(spclat) #TODO: Remove with list extraction
longitude.append(spclon) # TODO: Remove with list extraction
#
# Compute the geometric sub-boresight point.
#
if tar.frame == 'MARSIAU':
tar_frame = 'IAU_MARS'
else:
tar_frame = tar.frame
if boresight:
try:
id = spiceypy.bodn2c(boresight)
(shape,framen, bsight, n, bounds) = spiceypy.getfov(id, 80)
mat = spiceypy.pxform(framen,tar_frame,et)
except:
framen = boresight
bsight = 0,0,1
else:
bsight = self.name
try:
if tar.method == 'INTERCEPT/ELLIPSOID':
method = 'ELLIPSOID'
else:
method = tar.method
spoint, trgepc, srfvec = spiceypy.sincpt(method, tar.name, et,
tar_frame, time.abcorr,
self.name, framen,
bsight)
#
# Convert the sub-observer point's rectangular coordinates to
# planetographic longitude, latitude and altitude.
#
spglon, spglat, spgalt = spiceypy.recpgr(tar.name, spoint,
tar.radii_equ, tar.flat)
#
# Convert radians to degrees.
#
spglon *= spiceypy.dpr()
spglat *= spiceypy.dpr()
#
# Convert sub-observer point's rectangular coordinates to
# planetocentric radius, longitude, and latitude.
#
spcrad, spclon, spclat = spiceypy.reclat(spoint)
#
# Convert radians to degrees.
#
spclon *= spiceypy.dpr()
spclat *= spiceypy.dpr()
boresight_latitude.append(spclat)
boresight_longitude.append(spclon)
except:
pass
#
# Compute the angle between the observer's S/C axis and the
# geometric sub-observer point
#
obs_tar, ltime = spiceypy.spkpos(tar.name, et,
'J2000', time.abcorr,
self.name)
obs_zaxis = [0, 0, 1]
obs_myaxis = [0, -1, 0]
obs_yaxis = [0, 1, 0]
obs_xaxis = [1, 0, 0]
#
# We need to account for when there is no CK attitude available.
#
try:
matrix = spiceypy.pxform(self.frame, 'J2000', et)
z_vecout = spiceypy.mxv(matrix, obs_zaxis)
zax_target_angle = spiceypy.vsep(z_vecout, obs_tar)
zax_target_angle *= spiceypy.dpr()
zaxis_target_angle.append(zax_target_angle)
my_vecout = spiceypy.mxv(matrix, obs_myaxis)
myax_target_angle = spiceypy.vsep(my_vecout, obs_tar)
myax_target_angle *= spiceypy.dpr()
myaxis_target_angle.append(myax_target_angle)
y_vecout = spiceypy.mxv(matrix, obs_myaxis)
yax_target_angle = spiceypy.vsep(y_vecout, obs_tar)
yax_target_angle *= spiceypy.dpr()
yaxis_target_angle.append(yax_target_angle)
x_vecout = spiceypy.mxv(matrix, obs_myaxis)
xax_target_angle = spiceypy.vsep(x_vecout, obs_tar)
xax_target_angle *= spiceypy.dpr()
xaxis_target_angle.append(xax_target_angle)
quat = spiceypy.m2q(spiceypy.invert(matrix))
qs.append(quat[0])
qx.append(-1*quat[1])
qy.append(-1*quat[2])
qz.append(-1*quat[3])
except:
zaxis_target_angle.append(0.0)
myaxis_target_angle.append(0.0)
yaxis_target_angle.append(0.0)
xaxis_target_angle.append(0.0)
qs.append(0.0)
qx.append(0.0)
qy.append(0.0)
qz.append(0.0)
beta_angle.append(spiops.beta_angle(self.name, self.target.name,
et))
except:
boresight_latitude = 0
boresight_longitude = 0
distance = 0
altitude = 0
latitude = 0
longitude = 0
subpoint_xyz = [0,0,0]
subpoint_pgc = [0,0,0]
subpoint_pcc = [0,0,0]
zaxis_target_angle = 0
myaxis_target_angle = 0
yaxis_target_angle = 0
xaxis_target_angle = 0
beta_angle = 0
(qx, qy, qz, qs) = 0, 0, 0, 0
(x, y, z) = 0, 0, 0
self.boresight_latitude = boresight_latitude
self.boresight_longitude = boresight_longitude
self.distance = distance
self.altitude = altitude
self.latitude = latitude
self.longitude = longitude
self.subpoint_xyz = subpoint_xyz
self.subpoint_pgc = subpoint_pgc
self.subpoint_pcc = subpoint_pcc
self.zaxis_target_angle = zaxis_target_angle
self.myaxis_target_angle = myaxis_target_angle
self.yaxis_target_angle = yaxis_target_angle
self.xaxis_target_angle = xaxis_target_angle
self.beta_angle = beta_angle
self.quaternions = [qx, qy, qz, qs]
self.trajectory = [x,y,z]
self.geometry_flag = True
self.previous_tw = self.time.window
return
def cassini_titan_test(flyby, anodes=False):
times = []
states = []
lons, lats, alts = [], [], []
crossvecs_lonlatalts = []
crossvecs_lonlatalts_spicenormal = []
cmats = []
vecs = []
anode_vecs = []
anode_seps = [[], [], [], [], [], [], [], []]
anodes1, anodes8 = [], []
crossvecs = []
angularseparations = []
beamanodes = []
spiceplanenormals = []
windsdf = pd.read_csv("crosswinds_full.csv", index_col=0, parse_dates=True)
tempdf = windsdf[windsdf['Flyby'] == flyby]
for tempdatetime, negwindspeed, poswindspeed in zip(
pd.to_datetime(tempdf['Bulk Time']),
tempdf["Negative crosstrack velocity"],
tempdf["Positive crosstrack velocity"]):
print("---------")
print(tempdatetime)
times.append(tempdatetime)
beamanodes.append(np.mean(ELS_ramanodes(tempdatetime)) + 1)
states.append(cassini_phase(
tempdatetime.strftime('%Y-%m-%dT%H:%M:%S')))
# print(states[-1])
lon, lat, alt = spice.recpgr("TITAN", states[-1][:3],
spice.bodvrd("TITAN", 'RADII', 3)[1][0],
1.44e-4)
lons.append(lon * spice.dpr())
lats.append(lat * spice.dpr())
alts.append(alt)
# vecs.append(cassini_act_2_titan(tempdatetime))
crossvec = caps_crosstrack(tempdatetime,
np.mean([negwindspeed, poswindspeed]))
print("crossvec", crossvec)
testspicenormal, anode1, anode8 = caps_crosstrack_spice(
tempdatetime, np.mean([negwindspeed, poswindspeed]))
anodes1.append(anode1)
anodes8.append(anode8)
spiceplanenormals.append(testspicenormal)
print("test spice normal", testspicenormal)
jacobian = spice.dpgrdr("TITAN", states[-1][0], states[-1][1],
states[-1][2],
spice.bodvrd('TITAN', 'RADII',
3)[1][0], 1.44e-4)
# print("jacobian", jacobian)
crossvec_lonlatalt = spice.mxv(jacobian, spice.vhat(crossvec))
crossvec_lonlatalt_spicenormal = spice.mxv(jacobian, testspicenormal)
# print("recpgr", lon, lat, alt)
# print("crossvec latlon", crossvec_lonlatalt)
# print("crossvec latlon vhat", spice.vhat(crossvec_latlon))
crossvecs.append(crossvec)
crossvecs_lonlatalts.append(crossvec_lonlatalt)
crossvecs_lonlatalts_spicenormal.append(crossvec_lonlatalt_spicenormal)
# print("Time", tempdatetime)
# print("position", states[-1][:3])
# print("velocity", spice.vhat(states[-1][3:]))
# print("direction", spice.vhat(vecs[-1]))
# if anodes:
# anode_vecs.append(caps_all_anodes(tempdatetime))
# print("anode vecs 1 & 8", anode_vecs[-1][0], anode_vecs[-1][7])
# # spiceplanenormal = spice.psv2pl(states[-1][:3],anode_vecs[-1][0],anode_vecs[-1][7])
# # print("SPICE NORMAL", spice.pl2nvp(spiceplanenormal))
# #
# # spiceplanenormals.append(-1*spice.pl2nvp(spiceplanenormal)[0])
# # print("Crossvec", crossvec)
# for anodecounter, i in enumerate(anode_vecs[-1]):
# # print(anodecounter,anode_vecs[-1][anodecounter])
# anode_seps[anodecounter].append(
# spice.vsep(spice.vhat(states[-1][3:]), spice.vhat(anode_vecs[-1][anodecounter])) * spice.dpr())
# print("anodeseps",anode_seps)
# print("Angular Separation", spice.vsep(spice.vhat(states[-1][3:]), spice.vhat(vecs[-1])) * spice.dpr())
x, y, z, u, v, w = [], [], [], [], [], []
for i in states:
x.append(i[0])
y.append(i[1])
z.append(i[2])
# CAPS direction
for i in vecs:
u.append(i[0])
v.append(i[1])
w.append(i[2])
# Crosstrack
u2, v2, w2 = [], [], []
for j in crossvecs:
u2.append(j[0])
v2.append(j[1])
w2.append(j[2])
# SPICE plane normal
u3, v3, w3 = [], [], []
for j in spiceplanenormals:
u3.append(j[0])
v3.append(j[1])
w3.append(j[2])
# Ram Direction
u1, v1, w1 = [], [], []
for i in states:
u1.append(i[3])
v1.append(i[4])
w1.append(i[5])
fig = plt.figure()
u = np.linspace(0, 2 * np.pi, 50)
v = np.linspace(0, np.pi, 50)
x_sphere = 2574.7 * np.outer(np.cos(u), np.sin(v))
y_sphere = 2574.7 * np.outer(np.sin(u), np.sin(v))
z_sphere = 2574.7 * np.outer(np.ones(np.size(u)), np.cos(v))
ax = fig.add_subplot(111, projection='3d')
# Plot the surface
# ax.plot_wireframe(x_sphere, y_sphere, z_sphere, color='b')
# ax.plot(x, y, z, alpha=0.5, color='k')
if anodes:
for timecounter, (i, j) in enumerate(zip(anodes1, anodes8)):
X = x[timecounter]
Y = y[timecounter]
Z = z[timecounter]
# print(i)
# for anodecounter, j in enumerate(i):
# if anodecounter in [0, 7]:
# ax.quiver(X, Y, Z, j[0], j[1], j[2], length=20, color='C' + str(anodecounter))
# print(timecounter, i, j)
ax.quiver(X, Y, Z, i[0], i[1], i[2], length=30, color='C1')
ax.quiver(X, Y, Z, j[0], j[1], j[2], length=30, color='C2')
ax.quiver(x, y, z, u2, v2, w2, length=30, color='m')
ax.quiver(x, y, z, u1, v1, w1, length=5, color='k')
ax.quiver(x, y, z, u3, v3, w3, length=30, color='r')
ax.set_xlabel("X")
ax.set_ylabel("Y")
ax.set_zlabel("Z")
ax.set_xlim(min(x), max(x))
ax.set_ylim(min(y), max(y))
ax.set_zlim(min(z), max(z))
dlat, dlon = [], []
for i in crossvecs_lonlatalts:
dlat.append(i[1])
dlon.append(i[0])
dlat_spicenormal, dlon_spicenormal = [], []
for i in crossvecs_lonlatalts_spicenormal:
dlat_spicenormal.append(i[1])
dlon_spicenormal.append(i[0])
fig2, ax2 = plt.subplots()
ax2.plot(lons, lats)
ax2.quiver(lons, lats, dlon, dlat)
ax2.quiver(lons, lats, dlon_spicenormal, dlat_spicenormal, color='r')
ax2.set_xlabel("Longitude")
ax2.set_ylabel("Latitude")
ax2.grid()
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()
def vector_params(self, vector) :
ret = np.full(shape = [len(self.keys)], fill_value = -1000.0)
# Calculate the distance of the boresight and the center of the target
origin = np.array([0.0, 0.0, 0.0])
nearpoint, rayradius = spice.nplnpt(self.scloc, vector, origin)
# Get the intercept to calculate the radius of of the target
normal = spice.surfpt(origin, 1000.0 * nearpoint, self.radii[0], self.radii[1], self.radii[2])
ret[self.map['limb_distance']] = rayradius - spice.vnorm(normal)
# Calculate the 'occultation' latitude and longitude
ret[self.map['bodyintercept']], ret[self.map['limb_lat']], ret[self.map['limb_lon']] = spice.reclat(nearpoint)
# Test if the boresight intersects with our target surface
try:
point = spice.surfpt(self.scloc, vector, self.radii[0], self.radii[1], self.radii[2])
intercept = True
except:
intercept = False
if (intercept) :
# Get some angles
ret[self.map['phase']], ret[self.map['incidence']], ret[self.map['emission']] = spice.illum(self.target, self.et , self.abcorr, self.spacecraft, point)
# Calculate the planetocentric coordinates
distance, ret[self.map['lon']], ret[self.map['lat']] = spice.reclat(point)
ret[self.map['losdist']] = spice.vnorm(self.scloc - point)
# Calculate the planetographic coordinates
ret[self.map['lon_graphic']], ret[self.map['lat_graphic']], bodyintercept = spice.recpgr(self.target, point, self.radii[0], self.flattening)
# Get the localtime, and convert to decimal hours
hr, min, sc, time, ampm = spice.et2lst(self.et, self.target_id, ret[self.map['lon']], 'PLANETOCENTRIC')
ret[self.map['localtime']] = hr + min / 60.0 + sc / 3600.0
# For the angles, convert radians to degrees
for key in self.angles :
if (ret[self.map[key]] != -1000.0) :
ret[self.map[key]] = np.rad2deg(ret[self.map[key]])
# Makes sure longitudes wrap 0 to 360, spice returns the Earth-like -180 to 180.
longitudes = ['lon', 'limb_lon', 'lon_graphic']
for key in longitudes :
ret[self.map[key]] = ret[self.map[key]] % 360
return np.array(ret)
