def marvelProbe(params, verbose = False, MC = False):
'''
main function for MARVEL probes.
1) back-propagate probes for params.tback seconds
2) split probe into N separate probes
3) apply delta-V of params.DV to each probe in hard-coded directions
4) forward propagate to entry interface
5) call mainAD for each probe from entry interface to landing
'''
# get inertial cartesian state from given planet-relative spherical state
params.x0, params.vInfvec_N = LLAEHV2RV(params.lat, params.lon,
params.alt, params.efpaWR,
params.hdaWR, params.vmagWR,
params, params.tspan[0])
params.v0 = Vinf2VN(params.x0, params.vInfvec_N, params, params.tspan[0])
# propagate vehicle backwards in time by params.tback seconds
yy0 = np.block([params.x0, params.v0])
solBack = solve_ivp(lambda t, y: ODEs.TBP(t, y, params),
(params.tback, 0), yy0.flatten(), rtol = params.rtol,
atol = params.atol)
xx0vecCenter = solBack.y[:,-1]
x0vecCenter = xx0vecCenter[:3]
v0vecCenter = xx0vecCenter[3:]
# split probe into 4 separate probes
rDir = x0vecCenter / np.linalg.norm(x0vecCenter)
vDir = v0vecCenter / np.linalg.norm(v0vecCenter)
hDir = np.cross(rDir, vDir)
hDir = hDir / np.linalg.norm(hDir)
thDir = np.cross(hDir, rDir)
thDir = thDir / np.linalg.norm(thDir)
phi = np.radians(0)
eta = np.radians(0)
aDir = np.cos(phi) * thDir + np.sin(phi) * hDir
bDir = -aDir
cDir = np.cos(eta) * hDir - np.sin(eta) * thDir
dDir = -cDir
v0vecDown = v0vecCenter + params.DVDown * aDir
v0vecUp = v0vecCenter + params.DVUp * bDir
v0vecLeft = v0vecCenter + params.DVLeft * cDir
v0vecRight = v0vecCenter + params.DVRight * dDir
xx0vecDown = np.hstack([x0vecCenter, v0vecDown])
xx0vecUp = np.hstack([x0vecCenter, v0vecUp])
xx0vecLeft = np.hstack([x0vecCenter, v0vecLeft])
xx0vecRight = np.hstack([x0vecCenter, v0vecRight])
# pdb.set_trace()
# propagate each probe forward until atm interface
eventEI = lambda t, y: ODEs.above_max_alt(t, y, params)
eventEI.terminal = True
paramsDown = copy.deepcopy(params)
solDown = solve_ivp(lambda t, y: ODEs.TBP(t, y, params),
(0, 10 * params.tback), xx0vecDown, rtol = params.rtol,
atol = params.atol, events = (eventEI))
paramsDown.x0 = solDown.y[:3,-1]
paramsDown.v0 = solDown.y[3:,-1]
paramsDown.inputType = 'inertial vectors'
paramsUp = copy.deepcopy(params)
solUp = solve_ivp(lambda t, y: ODEs.TBP(t, y, params),
(0, 10 * params.tback), xx0vecUp, rtol = params.rtol,
atol = params.atol, events = (eventEI))
paramsUp.x0 = solUp.y[:3,-1]
paramsUp.v0 = solUp.y[3:,-1]
paramsUp.inputType = 'inertial vectors'
paramsLeft = copy.deepcopy(params)
solLeft = solve_ivp(lambda t, y: ODEs.TBP(t, y, params),
(0, 10 * params.tback), xx0vecLeft, rtol = params.rtol,
atol = params.atol, events = (eventEI))
paramsLeft.x0 = solLeft.y[:3,-1]
paramsLeft.v0 = solLeft.y[3:,-1]
paramsLeft.inputType = 'inertial vectors'
paramsRight = copy.deepcopy(params)
solRight = solve_ivp(lambda t, y: ODEs.TBP(t, y, params),
(0, 10 * params.tback), xx0vecRight, rtol = params.rtol,
atol = params.atol, events = (eventEI))
paramsRight.x0 = solRight.y[:3,-1]
paramsRight.v0 = solRight.y[3:,-1]
paramsRight.inputType = 'inertial vectors'
# propagate all 4 probes to the surface
outsDown = Outs()
outsUp = Outs()
outsLeft = Outs()
outsRight = Outs()
outsDown = mainAD(paramsDown, params.tspan, params.events, outsDown,
verbose = verbose)
outsUp = mainAD(paramsUp, params.tspan, params.events, outsUp,
verbose = verbose)
outsLeft = mainAD(paramsLeft, params.tspan, params.events, outsLeft,
verbose = verbose)
outsRight = mainAD(paramsRight, params.tspan, params.events, outsRight,
verbose = verbose)
# make sure that all probes enter atm at least 1 km away from orbiter
dista = greatCircleDistDeg(params.lon, params.lat,
outsDown.lon0, outsDown.lat0, params)
distb = greatCircleDistDeg(params.lon, params.lat,
outsUp.lon0, outsUp.lat0, params)
distc = greatCircleDistDeg(params.lon, params.lat,
outsLeft.lon0, outsLeft.lat0, params)
distd = greatCircleDistDeg(params.lon, params.lat,
outsRight.lon0, outsRight.lat0, params)
if min(dista, distb, distc, distd) < 1:
# sys.exit('a probe entered the atmosphere within {0:.3f} km of the'\
# ' orbtier'.format(min(dista, distb, distc, distd)))
print('a probe entered the atmosphere within {0:.3f} km of the'\
' orbtier'.format(min(dista, distb, distc, distd)))
# find minimum distance between two landing locations
distAB = greatCircleDistDeg(outsDown.lonf, outsDown.latf,
outsUp.lonf, outsUp.latf, params)
distAC = greatCircleDistDeg(outsDown.lonf, outsDown.latf,
outsLeft.lonf, outsLeft.latf, params)
distAD = greatCircleDistDeg(outsDown.lonf, outsDown.latf,
outsRight.lonf, outsRight.latf, params)
distBC = greatCircleDistDeg(outsUp.lonf, outsUp.latf,
outsLeft.lonf, outsLeft.latf, params)
distBD = greatCircleDistDeg(outsUp.lonf, outsUp.latf,
outsRight.lonf, outsRight.latf, params)
distCD = greatCircleDistDeg(outsLeft.lonf, outsLeft.latf,
outsRight.lonf, outsRight.latf, params)
minDist = min(distAB, distAC, distAD, distBC, distBD, distCD)
maxDist = max(distAB, distAC, distAD, distBC, distBD, distCD)
return outsDown, outsUp, outsLeft, outsRight, (minDist, maxDist)
event1 = lambda t, y: ODEs.below_min_alt(t, y, params) event1.terminal = True event2 = lambda t, y: ODEs.above_max_alt(t, y, params) event2.terminal = True event2.direction = 1 events = (event1, event2) params.events = events ### INTEGRATION TOLERANCE params.rtol = 1e-11 params.atol = 1e-11 outsCenter = Outs() outsCenter = mainAD(params, params.tspan, params.events, outsCenter) # ============================================================================= # Set up dispersion parameters # ============================================================================= # Number of Monte Carlo trials Nmc = 15 # Ballistic coefficient, U[0.95%, 1.05%] BCMean = params.BC BCLB = 0.95 * params.BC BCRng = 0.1 * params.BC # DV, U[90%, 110%] DVMean = DVnom
for i_trial in range(Nmc):
# generate input realizations
params.efpaWR = norm.rvs(size=1, loc=efpanom, scale=efpa_sig)[0]
params.vmagWR = norm.rvs(size=1, loc=vmagnom, scale=vmag_sig)[0]
params.CD = uniform.rvs(size=1, loc=CD_LB, scale=2 * (CD_UB - CDnom))[0]
params.m = uniform.rvs(size=1, loc=m_LB, scale=2 * (m_UB - mnom))[0]
params.BC = params.m / (params.CD * Anom)
# get atmosphere table for this trial
params.atmdat = np.array([h, densAll[:, i_trial]])
params.atmdat = params.atmdat[:, params.atmdat[0, :].argsort()]
# run sim
print('\nTrial {}'.format(i_trial + 1))
outs = Outs()
outsList.append(mainAD(params, tspan, events, outs))
paramsList.append(getQoIParams(params))
# every 50 trials, save all results to a file
if not i_trial % 50:
## Save results to a file
np.savez(outname,
paramsList=paramsList,
outsList=outsList,
CD_LB=CD_LB,
CD_UB=CD_UB,
m_LB=m_LB,
m_UB=m_UB,
efpanom=efpanom,
efpa_sig=efpa_sig,
params.hmax = params.p.halt + 1e-7 + 10
event1 = lambda t, y: ODEs.below_min_alt(t, y, params)
event1.terminal = True
event2 = lambda t, y: ODEs.above_max_alt(t, y, params)
event2.terminal = True
events = (event1, event2)
### SINGLE RUN
params.efpaWR = -6
params.BC = 50
outs = Outs()
outs = mainAD(params, tspan, events, outs)
print(outs.fpaf)
print(outs.engf)
### PLOTS
alt = np.linalg.norm(outs.rvec_N, axis=0) - params.p.rad #/1e3
vmag = np.linalg.norm(outs.vvec_N, axis=0)
fig = plt.figure(1)
ax = fig.add_subplot(111)
ax.plot(vmag, alt)
ax.set_xlabel('Inertial velocity, km/s')
ax.set_ylabel('Altitude, km')
ax.grid()
fig = plt.figure(2)
event1 = lambda t, y: ODEs.below_min_alt(t, y, params)
event1.terminal = True
event2 = lambda t, y: ODEs.above_max_alt(t, y, params)
event2.terminal = True
events = (event1, event2)
### SINGLE RUN
params.efpaWR = -12
params.BC = 130
### SIMULATE ORBITER
outsOrbiter = Outs()
outsOrbiter = mainAD(params, tspan, events, outsOrbiter)
print('\nORBITER:')
print('Final energy: {:.3f} km^2/s^2'.format(outsOrbiter.engf))
print('Apoapsis altitude: {:.3f} km'.format(outsOrbiter.haf))
print('Bank angle set to {:.1f} deg\n'.format(params.bank))
### SIMULATE PROBE
params.LD = 0
params.BC = 35
outsProbe = Outs()
outsProbe = mainAD(params, tspan, events, outsProbe)
print('\nPROBE:')
print('Final energy: {:.3f} km^2/s^2'.format(outsProbe.engf))
print('Apoapsis altitude: {:.3f} km'.format(outsProbe.haf))
# =============================================================================