''' '''
'''
ISC License
Copyright (c) 2016, Autonomous Vehicle Systems Lab, University of Colorado at Boulder
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
'''
from Basilisk.utilities import macros
import numpy as np
[docs]def exponentialAtmosphere(atmosModule, name):
"""
Sets the exponential atmosphere model parameters for a particular planet.
:param atmosModule: atmospheric environment module
:param name: planet name string
:return:
"""
if name is "earth":
atmosModule.planetRadius = 6378136.6 # meters
atmosModule.baseDensity = 1.217 # kg/m^3
atmosModule.scaleHeight = 8500.0 # meters
atmosModule.localTemp = 293.0
else:
print("ERROR: " + name + " not setup for exponential atmosphere model\n")
return
[docs]def centeredDipoleMagField(magFieldModule, name):
"""
Sets the centered dipole magnetic field model parameters for a particular planet
:param magFieldModule: magnetic field environment module
:param name: planet name string
:return:
"""
if name is "earth":
# The following parameters are from the 2020 IGRF model
# (https://www.ngdc.noaa.gov/IAGA/vmod/igrf.html)
magFieldModule.g10 = -30926.00/1e9 # Tesla
magFieldModule.g11 = -2318.00/1e9 # Tesla
magFieldModule.h11 = 5817.00/1e9 # Tesla
magFieldModule.planetRadius = 6371.2*1000 # meters
elif name is "mercury":
# The following parameters are from NASA planetary fact sheet
# (https://nssdc.gsfc.nasa.gov/planetary/planetfact.html)
magFieldModule.planetRadius = 2440.0*1000 # meters
convertToIgrfDipoleCoefficients(0.002/10000, # [T] dipole strength
0.0*macros.D2R, # [rad] Dipole tilt to rotational axis
0.0*macros.D2R, # [rad] Longitude of tilt
magFieldModule)
elif name is "jupiter":
# The following parameters are from NASA planetary fact sheet
# (https://nssdc.gsfc.nasa.gov/planetary/planetfact.html)
magFieldModule.planetRadius = 71398.0*1000 # meters
convertToIgrfDipoleCoefficients(4.30/10000, # [T] dipole strength
9.4*macros.D2R, # [rad] Dipole tilt to rotational axis
200.1*macros.D2R, # [rad] Longitude of tilt
magFieldModule)
elif name is "saturn":
# The following parameters are from NASA planetary fact sheet
# (https://nssdc.gsfc.nasa.gov/planetary/planetfact.html)
magFieldModule.planetRadius = 60330.0*1000 # meters
convertToIgrfDipoleCoefficients(0.215/10000, # [T] dipole strength
0.0*macros.D2R, # [rad] Dipole tilt to rotational axis
0.0*macros.D2R, # [rad] Longitude of tilt
magFieldModule)
elif name is "uranus":
# The following parameters are from NASA planetary fact sheet
# (https://nssdc.gsfc.nasa.gov/planetary/planetfact.html)
magFieldModule.planetRadius = 25600.0*1000 # meters
convertToIgrfDipoleCoefficients(0.228/10000, # [T] dipole strength
58.6*macros.D2R, # [rad] Dipole tilt to rotational axis
53.6*macros.D2R, # [rad] Longitude of tilt
magFieldModule)
elif name is "neptune":
# The following parameters are from NASA planetary fact sheet
# (https://nssdc.gsfc.nasa.gov/planetary/planetfact.html)
magFieldModule.planetRadius = 24765.0*1000 # meters
convertToIgrfDipoleCoefficients(0.142/10000, # [T] dipole strength
46.9*macros.D2R, # [rad] Dipole tilt to rotational axis
288.*macros.D2R, # [rad] Longitude of tilt
magFieldModule)
else:
print("ERROR: " + name + " not setup for centered dipole magnetic field model. Options include mercury, earth, jupiter, saturn, uranus and neptune. \n")
return
[docs]def convertToIgrfDipoleCoefficients(nominalField, tilt, longitudeOfTilt, magFieldModule):
"""
Converts the NASA Magnetosphere parameters from https://nssdc.gsfc.nasa.gov/planetary/planetfact.html
to IGRF compatible dipole coefficients.
:param nominalField: nominal magnetic field parameter given in Tesla
:param tilt: Dipole tilt to rotational axis in radians
:param longitudeOfTilt: Longitude of tilt in radians
:param magFieldModule: magnetic field environment module
:return:
"""
# the following conversion is taken from Appendix D of doi:10.1007/978-1-4939-0802-8
theta_m = np.pi - tilt
alpha_m = np.pi - longitudeOfTilt
magFieldModule.g11 = nominalField*np.sin(theta_m)*np.cos(alpha_m)
magFieldModule.h11 = nominalField*np.sin(theta_m)*np.sin(alpha_m)
magFieldModule.g10 = nominalField*np.cos(theta_m)
return