def computeOccultations(self, observer_in, occultation_bodies_in,
target_in, target_shape_in, target_frame_in,
step_size_in, aberration_correction_in,
greg_format_string_in):
self.greg_format_string = greg_format_string_in
split_string = self.greg_format_string.split(' ')
self.time_system_string = [i for i in split_string if '::' in i][0][2:]
self.observer = str(observer_in)
self.occultation_bodies = occultation_bodies_in
self.target = target_in
self.target_shape = target_shape_in
self.target_frame = target_frame_in
self.search_step_size = step_size_in
self.aberration_correction = aberration_correction_in
self.cumulative_results = {}
for body in self.occultation_bodies:
# add a new key to the results dictionary for this body
self.cumulative_results[body.name] = []
for occultation_type in body.occultation_types:
body.search_start_ET_seconds = spice.str2et(body.search_start)
body.search_end_ET_seconds = spice.str2et(body.search_end)
spice.wninsd(body.search_start_ET_seconds,
body.search_end_ET_seconds,
self.SPICE_search_window)
spice.gfoclt(occultation_type, body.name, body.shape,
body.frame, self.target, self.target_shape,
self.target_frame, self.aberration_correction,
self.observer, self.search_step_size,
self.SPICE_search_window, self.results_window)
winsiz = spice.wncard(self.results_window)
for body_index in range(winsiz):
[intbeg, intend] = spice.wnfetd(self.results_window,
body_index)
btmstr = spice.timout(intbeg, self.greg_format_string)
etmstr = spice.timout(intend, self.greg_format_string)
occultation_event = OccultationEvent()
occultation_event.start = btmstr
occultation_event.stop = etmstr
occultation_event.start_JD = greg2Julian(btmstr)
occultation_event.stop_JD = greg2Julian(etmstr)
occultation_event.duration = intend - intbeg
occultation_event.type = occultation_type
occultation_event.observer = self.observer
occultation_event.occulting_body = body.name
occultation_event.occulting_body_shape = body.shape
occultation_event.target = self.target
occultation_event.target_body_shape = self.target_shape
self.cumulative_results[body.name].append(
occultation_event)
def occultations(body1, body2, start, end):
cnfine = spiceypy.utils.support_types.SPICEDOUBLE_CELL(MAXWIN)
result = spiceypy.utils.support_types.SPICEDOUBLE_CELL(MAXWIN)
# Obtain the TDB time bounds of the confinement
# window, which is a single interval in this case.
et0 = spiceypy.str2et(start)
et1 = spiceypy.str2et(end)
# Insert the time bounds into the confinement window
spiceypy.wninsd(et0, et1, cnfine)
# 15-minute step. Ignore any occultations lasting less than 15 minutes.
# Units are TDB seconds.
step = 900.0
obsrvr = "Earth"
# Loop over the occultation types.
for occtype in types:
# For each type, do a search for both transits of
# Titan across Saturn and occultations of Titan by Saturn.
for j in range(2):
if not j:
front = body1
fframe = "IAU_" + body1
back = body2
bframe = "IAU_" + body2
else:
front = body2
fframe = "IAU_" + body2
back = body1
bframe = "IAU_" + body1
spiceypy.gfoclt(occtype, front, "ellipsoid", fframe, back,
"ellipsoid", bframe, "lt", obsrvr, step, cnfine,
result)
# Display the results
print()
title = spiceypy.repmc("Condition: # occultation of # by #", "#",
occtype)
title = spiceypy.repmc(title, "#", back)
title = spiceypy.repmc(title, "#", front)
print(title)
for r in result:
print(spiceypy.timout(r, "YYYY Mon DD HR:MN:SC"))
def core():
class SpiceVariables:
obs = '-74' # NAIF code for MEX
target = 'MARS ODYSSEY' # NAIF code for TGO ['EARTH'/'SUN'/ a groundstation etc]
obsfrm = 'IAU_MARS'
abcorr = 'NONE'
crdsys = 'LATITUDINAL'
coord = 'LATITUDE'
stepsz = 100.0 # Check every 300 seconds if there is an occultation
MAXILV = 100000 #Max number of occultations that can be returned by gfoclt
bshape = 'POINT'
fshape = 'DSK/UNPRIORITIZED'
front = 'MARS'
fframe = 'IAU_MARS'
TFMT = 'YYYY-MM-DD HR:MN:SC' # Format that Cosmographia understands
sv = SpiceVariables()
#-----------------------------------------------------<VALUES TO EDIT REGULARLY>----------------------------------------
# If you only wish to analysis mutual [cross-link] occultation between MEX and TGO, then this is the only section that
# needs to be edited
start = '2020 MAR 1'
stop = '2020 MAR 3'
OCCSELECTION = 17 # Which occultation do you wish to see in Cosmographia? [optional]
here = path.abspath(path.dirname(__file__))
PathtoMetaKernel1 = here + '/TGO/krns/mk/em16_plan.tm'
PathtoMetaKernel2 = here + '/MEX/krns/mk/MEX_OPS.tm'
#-----------------------------------------------------------------------------------------------------------------------
spice.furnsh(PathtoMetaKernel1)
spice.furnsh(PathtoMetaKernel2)
sv = SpiceVariables()
# Setting Variables
ingresslist = np.array([1.0], dtype=float)
etbeg = spice.str2et(start)
etend = spice.str2et(stop)
# Form a windows that gfoclt can populate
window = stypes.SPICEDOUBLE_CELL(2)
spice.wninsd(etbeg, etend, window)
occwindow = stypes.SPICEDOUBLE_CELL(sv.MAXILV)
#find occultation windows between the dates listed above [ most comp cost in this function]
spice.gfoclt('ANY', sv.front, sv.fshape, sv.fframe, sv.target, sv.bshape,
'J2000', sv.abcorr, sv.obs, sv.stepsz, window, occwindow)
winsiz = spice.wncard(occwindow) # Find cardinality (number of windows)
#initialize lists to form dataframe
lon, lat, dist, sza, angle = (np.ones(winsiz - 1) for i in range(5))
# Enter the ingress epochs into a dataframe
occlist = np.ones((winsiz, 3))
for i in range(winsiz):
[ingress, egress
] = spice.wnfetd(occwindow,
i) # extract the begining and ends of the windows
if i == 1:
ingresslist = ingress
else:
ingresslist = np.append(ingresslist, [ingress])
occs = pd.DataFrame(ingresslist, columns=['Time'])
occ = occs.Time[OCCSELECTION]
return occ
# sv = main.SpiceVariables()
# occ = core()
#print("strange result:", occ)
# #print(result)
# #form the dataframe
# length = 120
# occs = pd.DataFrame(ingresslist, columns=['Time'])
# residualdoppler = np.zeros(length)
# velocitydoppler = np.zeros(length)
# RESIDUALSUM = np.zeros(length)
# #Calculate the residual doppler as the sum of the neutral and ionosphere
# tic = timer.perf_counter()
# for time in tqdm(range(length)): #begin time at occultation epoch and go to 2 mins pior
# ray, dist, totalperiods, remainingdistance = main.producegeometrylamda(occs.Time[OCCSELECTION], sv, time*8)# Produce geometry in wavelenghts to investigate electric distance
# _,_,_,_, alt = main.Location(occs.Time[OCCSELECTION], sv, time*8)
# ionoresidual = atmosphere.iono(ray[2,:],totalperiods)
# neutralresidual = atmosphere.neutral(ray[2,:],totalperiods)
# residual = 1 + (ionoresidual + neutralresidual)
# # plt.plot(range(totalperiods),residual[0,:])
# # plt.title("Refractive Index through Propergation of Ray")
# # plt.xlabel("MEX->TGO distance (km)")
# # plt.ylabel("Refractive Index")
# # plt.show()
# #DO A TEST TO SEE IF THE NET REFRACTIVE INDEX CHANGES OVER TIME, THEN U CAN HONE IN ON THE ERRRO
# # account for the plus 1
# [electricdistance, geometric, resdopplershift] = main.doppler(residual, totalperiods, dist, remainingdistance)
# miss = electricdistance - dist + remainingdistance # a possitive number as electric distance is greater that geometric due to iono
# howwrongurcodeis = geometric - dist # is this purly due to rounding of that 9945 (each 1 is ~685 m)
# residualdoppler[time] = resdopplershift
# #find the geometric doppler too UNTESTED MODULE
# sc2scstates = spice.spkezr(sv.target, (occs.Time[OCCSELECTION] - time*8), sv.fframe, 'LT+S', sv.obs)
# velocityvector = sc2scstates[0][3:6]
# velocityvector = velocityvector[0:3]
# positionalvector = sc2scstates[0][0:3]
# positionalvector = positionalvector[0:3]
# velocityangle = spice.vsep( positionalvector, velocityvector) #rads
# relativevelocity = np.linalg.norm(velocityvector) * np.cos(velocityangle)
# geometricdopplershift = -(relativevelocity/constants.c) * 437.1e6
# velocitydoppler[time] = geometricdopplershift *1000 # becuase spice is in km and c is in m
# toc = timer.perf_counter()
# passingtime = toc-tic
# print('elapsed time in seconds:', passingtime)
# noise = np.random.normal(0,50,velocitydoppler.shape)
# RESIDUALSUM = residualdoppler + velocitydoppler + noise
# fig, ax = plt.subplots(3)
# ax[0].plot(range(-960,0,8),velocitydoppler[: : -1] )
# ax[0].set_title('Geometric', loc='left')
# ax[0].set_xlabel('Time after Occ (s)')
# ax[0].set_ylabel('Doppler Shift (Hz)')
# ax[1].plot(range(-960,0,8),residualdoppler[: : -1] )
# ax[1].set_title('Residual', loc='left')
# ax[1].set_xlabel('Time after Occ (s)')
# ax[1].set_ylabel('Doppler Shift (Hz)')
# ax[2].plot(range(-960,0,8),RESIDUALSUM[: : -1])
# ax[2].set_title('Product + Noise', loc='left')
# ax[2].set_xlabel('Time to Horizon Epoch (s)')
# ax[2].set_ylabel('Doppler Shift (Hz)')
# plt.show()
# #then add noise
spice.furnsh(sd.pck00010)
sc = SC({
'date0': '2021-03-03 22:10:35 TDB',
'coes': [7480.0, 0.09, 5.5, 6.26, 5.95, 0.2],
'tspan': '40',
})
st.write_bsp(sc.ets, sc.states[:, :6], {'bsp_fn': 'leo.bsp'})
spice.furnsh('leo.bsp')
et0 = spice.str2et('2021-03-03 22:10:40 TDB')
etf = spice.str2et('2021-03-04 TDB')
timecell = spice.utils.support_types.SPICEDOUBLE_CELL(2)
spice.appndd(et0, timecell)
spice.appndd(etf, timecell)
cell = spice.gfoclt('ANY', '399', 'ELLIPSOID', 'IAU_EARTH', '10',
'ELLIPSOID', 'IAU_SUN', 'LT', '-999', 120.0, timecell)
ets_SPICE = spice.wnfetd(cell, 0)
cal0 = spice.et2utc(ets_SPICE[0], 'C', 1)
cal1 = spice.et2utc(ets_SPICE[1], 'C', 1)
print('\n*** SPICE RESULTS ***')
print(f'{cal0} --> {cal1}')
sc.plot_3d()
sc.calc_eclipses(vv=True)
sc.plot_eclipse_array({'time_unit': 'seconds', 'show': True})
# pd.DataFrame(geometricdopplershift).to_csv("geometricdopplershift.csv")
# Setting Variables
ingresslist = np.array([1.0], dtype=float)
egresslist = np.array([1.0], dtype=float)
etbeg = spice.str2et(start)
etend = spice.str2et(stop)
# Form a windows that gfoclt can populate
window = stypes.SPICEDOUBLE_CELL(2)
spice.wninsd(etbeg, etend, window)
occwindow = stypes.SPICEDOUBLE_CELL(sv.MAXILV)
# find occultation windows between the dates listed above [ most comp cost in this function]
spice.gfoclt('ANY', sv.front, sv.fshape, sv.fframe, sv.target, sv.bshape, '',
sv.abcorr, sv.obs, sv.stepsz, window, occwindow)
winsiz = spice.wncard(occwindow) # Find cardinality (number of windows)
# initialize lists to form dataframe
lon, lat, dist, sza, angle = (np.ones(winsiz - 1) for i in range(5))
# Enter the ingress epochs into a dataframe
occlist = np.ones((winsiz, 3))
for i in range(winsiz):
# extract the begining and ends of the windows
[ingress, egress] = spice.wnfetd(occwindow, i)
if i == 1:
ingresslist = ingress
egresslist = egress
else: