def set_coe(self, coe, units = None, rv = True):
if units != None:
from unit_conversions import converter
coe[2] = converter(coe[2], units, 'Radians')
coe[3] = converter(coe[3], units, 'Radians')
coe[4] = converter(coe[4], units, 'Radians')
coe[5] = converter(coe[5], units, 'Radians')
# reset coe
self.sma = coe[0]
self.e = coe[1]
self.i = coe[2]
self.RAAN = coe[3]
self.AOP = coe[4]
self.f = coe[5]
self.coe = [self.sma, self.e, self.i, self.RAAN, \
self.AOP, self.f]
# reset r, v
if rv:
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
# recalculate additional useful orbital parameters
#+ E: eccentricy anomaly
#+ M: mean anomaly
#+ T: orbital period
#+ n: mean motion
from auxiliary import f2E, E2M, orbitalperiod
from math import pi
self.E = f2E(self.e, self.f)
self.M = E2M(self.e, self.E)
self.T = orbitalperiod(self.Mu, self.sma)
self.n = 2.0*pi / self.T
def flow(self, delta_time, SaveFlow = False):
if self.eom == 'keplerian':
from kepler import kepler
from auxiliary import E2f, E2M, coe2rv
# create a list of the necessary orbital parameters
#+ for ephemeris() and order them in the default order
ephemeris_list = [self.e, self.n, self.E]
ephemeris_list = kepler(ephemeris_list, delta_time)
# update other relevant orbital parameters
self.epoch += delta_time
self.E = ephemeris_list[2]
self.f = E2f(self.e, self.E)
self.M = E2M(self.e, self.E)
# update coe list
self.coe[5] = self.f
# update the r, v vectors
self.r, self.v = coe2rv(self.coe, self.Mu)
elif self.eom == 'P2B':
from utilities import rv2ic
from flow import P2B
ic = rv2ic(self.r[0:2], self.v[0:2], self.Mu, STM = False)
flow = P2B(ic, [0, delta_time])
self.epoch += delta_time
self.r[0:2] = flow['y'][-1][0:2]
self.v[0:2] = flow['y'][-1][2:4]
elif self.eom == 'P2B_varEqns':
from utilities import rv2ic
from flow import P2B
ic = rv2ic(self.r[0:2], self.v[0:2], self.Mu, STM = True)
flow = P2B(ic, [0, delta_time], eom = 'P2BP_varEqns')
self.epoch += delta_time
self.r[0:2] = flow['y'][-1][0:2]
self.v[0:2] = flow['y'][-1][2:4]
self.STM = flow['y'][-1][5:]
elif self.eom == 'S2B':
from utilities import rv2ic
from flow import S2B
ic = rv2ic(self.r, self.v, self.Mu, STM = False)
flow = S2B(ic, [0, delta_time])
self.epoch += delta_time
self.r = flow['y'][-1][0:3]
self.v = flow['y'][-1][3:6]
elif self.eom == 'S2B_varEqns':
from utilities import rv2ic
from flow import S2B
ic = rv2ic(self.r, self.v, self.Mu, STM = True)
flow = S2B(ic, [0, delta_time], tstep = delta_time/1E3, \
eom = 'S2BP_varEqns')
self.epoch += delta_time
self.r = flow['y'][-1][0:3]
self.v = flow['y'][-1][3:6]
self.STM = flow['y'][-1][6:]
# save the r, v and t history when not using 'keplerian'
if self.eom != 'keplerian':
n = len(self.r)
from utilities import extract_elements
extract_elements(flow['y'], 0, n - 1, self.r_history)
extract_elements(flow['y'], n, 2*n - 1, self.v_history)
self.t_history = flow['x']
if SaveFlow: self.theflow = flow
def set_AOP(self, AOP, units = None):
if units != None:
from unit_conversions import converter
AOP = converter(AOP, units, 'Radians')
self.AOP = AOP
# reset AOP in coe list
self.coe[4] = AOP
# reset the r and v vectors
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
def set_RAAN(self, RAAN, units = None):
if units != None:
from unit_conversions import converter
RAAN = converter(RAAN, units, 'Radians')
self.RAAN = RAAN
# reset RAAN in coe list
self.coe[3] = RAAN
# reset the r and v vectors
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
def set_i(self, i, units = None):
if units != None:
from unit_conversions import converter
i = converter(i, units, 'Radians')
self.i = i
# reset i in coe list
self.coe[2] = i
# reset the r and v vectors
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
def set_e(self, e):
self.e = e
# reset e in coe list
self.coe[1] = e
# reset the r and v vectors
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
# reset
#+ E: eccentricy anomaly
#+ M: mean anomaly
from auxiliary import f2E, E2M
self.E = f2E(self.e, self.f)
self.M = E2M(self.e, self.E)
def set_sma(self, sma):
self.sma = sma
# reset sma in coe list
self.coe[0] = sma
# reset the r and v vectors
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
# reset the orbital period
from auxiliary import orbitalperiod
self.T = orbitalperiod(self.Mu, self.sma)
# reset the mean motion
from math import pi
self.n = 2.0*pi / self.T
def set_f(self, f, units = None):
if units != None:
from unit_conversions import converter
f = converter(f, units, 'Radians')
self.f = f
# reset f in coe list
self.coe[5] = f
# reset the r and v vectors
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
# reset
#+ E: eccentricy anomaly
#+ M: mean anomaly
from auxiliary import f2E, E2M
self.E = f2E(self.e, self.f)
self.M = E2M(self.e, self.E)
def set_parameters(self, body, altitude = 400.0):
import solarsystem_objects_parameters as ss
# setup parameters for the requested body if available
# first see if the user is requesting the 'Earth' or
#+ if the body is not on the given list, then default
#+ to the 'Earth'
if body == 'earth' or body not in ss.list:
self.name = 'earth'
# default classical orbital elements is
#+ earth about sun
self.sma = ss.earth['SemiMajor']
self.e = ss.earth['Eccentricity']
self.i = ss.earth['Inclination']
self.RAAN = 0.0
self.AOP = 0.0
self.f = 0.0
# epoch (Julian Date), default January 3rd 2014
#+ which is roughly when the Earth is at periapsis
self.epoch = 2456660.500000 * 86400.0
# mass and mu of the body
self.mass = ss.earth['Mass']
self.mu = ss.earth['Mu']
# radius of body
self.radius = ss.earth['Radius']
# set the gravitational constant of 'self'
#+ central body
self.Mu = ss.sun['Mu']
if body == 'sun':
self.name = 'sun'
# default classical orbital elements is
#+ earth about sun
self.sma = 0.0
self.e = 0.0
self.i = 0.0
self.RAAN = 0.0
self.AOP = 0.0
self.f = 0.0
# epoch (Julian Date), default January 3rd 2014
#+ which is roughly when the Earth is at periapsis
self.epoch = 2456660.500000 * 86400.0
# mass and mu of the body
self.mass = ss.sun['Mass']
self.mu = ss.sun['Mu']
# radius of body
self.radius = ss.sun['Radius']
# set the gravitational constant of 'self'
#+ central body
self.Mu = ss.sun['Mu']
if body == 'moon':
self.name = 'moon'
# default classical orbital elements is
#+ earth about sun
self.sma = ss.moon['SemiMajor']
self.e = ss.moon['Eccentricity']
self.i = ss.moon['Inclination']
self.RAAN = 0.0
self.AOP = 0.0
self.f = 0.0
# epoch (Julian Date), default January 3rd 2014
#+ which is roughly when the Earth is at periapsis
self.epoch = 2456660.500000 * 86400.0
# mass and mu of the body
self.mass = ss.moon['Mass']
self.mu = ss.moon['Mu']
# radius of body
self.radius = ss.moon['Radius']
# set the gravitational constant of 'self'
#+ central body
self.Mu = ss.earth['Mu']
if body == 'mars':
self.name = 'mars'
# default classical orbital elements is
#+ earth about sun
self.sma = ss.mars['SemiMajor']
self.e = ss.mars['Eccentricity']
self.i = ss.mars['Inclination']
self.RAAN = 0.0
self.AOP = 0.0
self.f = 0.0
# epoch (Julian Date), default January 3rd 2014
#+ which is roughly when the Earth is at periapsis
self.epoch = 2456660.500000 * 86400.0
# mass and mu of the body
self.mass = ss.mars['Mass']
self.mu = ss.mars['Mu']
# radius of body
self.radius = ss.mars['Radius']
# set the gravitational constant of 'self'
#+ central body
self.Mu = ss.sun['Mu']
if body == 'LEO':
self.name = 'leo_spacecraft'
# default classical orbital elements is
#+ spacecraft about earth
from math import pi
self.sma = ss.earth['Radius'] + altitude
self.e = 0.0
self.i = 28.5 * pi / 180.0
self.RAAN = 0.0
self.AOP = 0.0
self.f = 0.0
# epoch (Julian Date), default January 3rd 2014
#+ which is roughly when the Earth is at periapsis
self.epoch = 2456660.500000 * 86400.0
# mass and mu of the body
self.mass = 1000.0
self.mu = 0.0
# set the gravitational constant of 'self'
#+ central body
self.Mu = ss.earth['Mu']
# place the classical orbital elements into an array
self.coe = [self.sma, self.e, self.i, self.RAAN, \
self.AOP, self.f]
# calculate the r, v vectors for 'self'
#+ based on the classical orbital elements 'coe'
from auxiliary import coe2rv
self.r, self.v = coe2rv(self.coe, self.Mu)
# calculate additional useful orbital parameters
#+ E: eccentricy anomaly
#+ M: mean anomaly
#+ T: orbital period
#+ n: mean motion
from auxiliary import f2E, E2M, orbitalperiod
from math import pi
self.E = f2E(self.e, self.f)
self.M = E2M(self.e, self.E)
self.T = orbitalperiod(self.Mu, self.sma)
self.n = 2.0*pi / self.T