def zDot(self, t):
day = t/24/60/60
mjd = day + self.jdDep
stateCyl, __, __ = ephemeris(self.body, mjd, mode=self.ephemSource)
return stateCyl[5]
def samplePlanets(self, add=[]):
'''
Returns the state of the bodies visited during the patched transfer
Ephemeris source is passed as a list in self.ephems
The body names defined in the transfer objects must correspond to the
names or IDs expected by the ephemeris source
add manually adds another body to be included in the plot
Output structure: Dictionary with a sub-dictionary for each body,
containing a (3 x samples) numpy array
'''
print('Sample celestial body ephemerides')
# retrieve names of all visited bodies
bodyNames = []
bodyPykep = []
for trans in self.transfers:
body1 = trans.departureBody
body2 = trans.arrivalBody
bodyNames.extend([body1, body2])
for entry in add:
bodyNames.extend(entry)
# remove duplicates (kepping the order)
# bodyNames = list(set(bodyNames))
bodyNames = list(OrderedDict.fromkeys(bodyNames))
print(f'Visited bodies: {bodyNames}')
# retrieve the corresponding ephemeris source if mode is 'auto'
# else default to the spice ephemerides
# Example syntax for spice: '1234', for jpl: 'mars', for gtoc2: 123
mode = []
if self.ephems == 'auto':
for body in bodyNames:
if type(body) == str:
try:
int(body)
mode.append('spice')
except ValueError:
mode.append('jpl')
else:
mode.append('gtoc2')
else:
mode = ['spice'] * len(bodyNames)
# create nested dictionary
states = ['rCart', 'vCart', 'rCyl', 'vCyl']
bodyEphemeris = {
name: {state: np.empty([3, self.samples])
for state in states}
for name in bodyNames
}
# retrieve values for each body and each state vector
# for body in bodyNames:
# pkBody = pk.planet.spice(body, 'sun', 'eclipj2000')
# for i, t in enumerate(self.tSamples):
# rCart, vCart = pkBody.eph(t)
# bodyEphemeris[body]['rCart'][:, i] = rCart
# bodyEphemeris[body]['vCart'][:, i] = vCart
# bodyEphemeris[body]['rCyl'][:, i] = Pcart2cyl(rCart)
# bodyEphemeris[body]['vCyl'][:, i] = Vcart2cyl(vCart, rCart)
# retrieve values for each body and each state vector
for j, body in enumerate(bodyNames):
for i, t in enumerate(self.tSamples):
stateCyl, stateCart, __ = ephemeris(body, t, mode=mode[j])
bodyEphemeris[body]['rCart'][:, i] = stateCart[0:3]
bodyEphemeris[body]['vCart'][:, i] = stateCart[3:6]
bodyEphemeris[body]['rCyl'][:, i] = stateCyl[0:3]
bodyEphemeris[body]['vCyl'][:, i] = stateCyl[3:6]
return bodyEphemeris, bodyNames
def r(self, t):
# convert time from [s since launch] to [mjd2000]
day = t/24/60/60
mjd = day + self.jdDep
stateCyl, __, __ = ephemeris(self.body, mjd, mode=self.ephemSource)
return stateCyl[0]
def planetSystem(self,
save=None,
folder=None,
plotSOI=False,
scaling=False):
'''
Plots the orbits of the visited planets
Options: save save the plot (True/False) in png and pdf
folder specify differing folder for the saved plot
plotSOI plots the sphere of influence of the planets
scaling adjusts the axis limits to the same, summetric
range, pass a number in [AU]
'''
print('Plot the planets in 3D.')
ephem = self.bodyEphemeris
# start figure
fig = newFigure(height=6, target='paper')
ax = fig.gca(projection='3d')
# Sun
ax.scatter([0], [0], [0],
s=100,
color='yellow',
label='Sun',
marker='o',
edgecolor='orange')
# celestial bodies: orbits and position at launch
for body in self.bodyNames:
ax.plot(ephem[body]['rCart'][0, :] / pk.AU,
ephem[body]['rCart'][1, :] / pk.AU,
ephem[body]['rCart'][2, :] / pk.AU,
label=body)
ax.scatter(ephem[body]['rCart'][0, 0] / pk.AU,
ephem[body]['rCart'][1, 0] / pk.AU,
ephem[body]['rCart'][2, 0] / pk.AU)
if plotSOI:
plotting = True
if body == '1':
jplName = 'mercury'
elif body == '2':
jplName = 'venus'
if body == '3':
jplName = 'earth'
elif body == '4':
jplName = 'mars'
elif body == '5':
jplName = 'jupiter'
elif body == '6':
jplName = 'saturn'
elif body == '7':
jplName = 'uranus'
elif body == '8':
jplName = 'neptune'
else:
print(f'\tNo SOI computed for {body}.')
plotting = False
if plotting:
__, __, planet = ephemeris(jplName, 0, mode='jpl')
muBody = planet.mu_self
muCentral = pk.MU_SUN
rSOI = np.sqrt(
ephem[body]['rCart'][0, 0]**2
+ ephem[body]['rCart'][1, 0]**2
+ ephem[body]['rCart'][2, 0]**2)\
* (muBody/muCentral)**(2/5)
self.plotSphere(ephem[body]['rCart'][:, 0] / pk.AU,
rSOI / pk.AU)
# print(f'\tGravitational parameter {body}: {muBody:.2E} m^3/s^2')
print(
f'\tRadius of SOI {body}: {rSOI/1e3:.2E} km = {rSOI/pk.AU:.2E} AU'
)
# formatting
if scaling:
axisEqual3D(ax)
# ax.set_xlim(-scaling, scaling)
# ax.set_ylim(-scaling, scaling)
# ax.set_zlim(-scaling, scaling)
ax.set_xlabel('x [AU]', labelpad=15)
ax.set_ylabel('y [AU]', labelpad=15)
ax.set_zlabel('z [AU]', labelpad=15)
plt.grid()
plt.legend(loc='lower right')
if save == None:
save = self.save
if folder == None:
folder = self.folder
if save:
checkFolder(folder)
plt.savefig(os.path.join(os.getcwd(), folder, 'solarSystem.pdf'),
dpi=300)
plt.savefig(os.path.join(os.getcwd(), folder, 'solarSystem.png'),
dpi=300)
if self.show:
plt.show()