def datetime2Lgm(*args):
'''Convenience function to convert Python datetime to Lgm date and utc format
Parameters
----------
time_in: datetime.datetime
the input time to convert to a different system
Outputs
-------
datelong: long
LanlGeoMag long integer date representation (YYYYMMDD)
utc: float
LanlGeoMag floating point time-of-day (UTC) representation
'''
if len(args) == 1:
time_in = args[0]
else:
raise ValueError('Invalid arguments supplied in function call')
if _spacepy:
if isinstance(time_in, spt.Ticktock):
raise NotImplementedError('SpacePy compatibility not yet enabled')
try:
datelong = Lgm_CTrans.dateToDateLong(time_in)
utc = Lgm_CTrans.dateToFPHours(time_in)
except AttributeError:
raise TypeError("Date must be a datetime object")
return datelong, utc
def datetime2Lgm(*args):
'''Convenience function to convert Python datetime to Lgm date and utc format
Parameters
----------
time_in: datetime.datetime
the input time to convert to a different system
Outputs
-------
datelong: long
LanlGeoMag long integer date representation (YYYYMMDD)
utc: float
LanlGeoMag floating point time-of-day (UTC) representation
'''
if len(args) == 1:
time_in = args[0]
else:
raise ValueError('Invalid arguments supplied in function call')
if _spacepy:
if isinstance(time_in, spt.Ticktock):
raise NotImplementedError('SpacePy compatibility not yet enabled')
try:
datelong = Lgm_CTrans.dateToDateLong(time_in)
utc = Lgm_CTrans.dateToFPHours(time_in)
except AttributeError:
raise TypeError("Date must be a datetime object")
return datelong, utc
def test_dateToFPHours(self):
"""dateToFPHours should give known output for known input"""
d1 = datetime.datetime(2000, 12, 12)
self.assertEqual(0.0, Lgm_CTrans.dateToFPHours(d1))
for val in range(24):
self.assertEqual(val,
Lgm_CTrans.dateToFPHours(datetime.datetime(2000, 12, 12, val)))
self.assertEqual(12.5, Lgm_CTrans.dateToFPHours([datetime.datetime(2000, 12, 12, 12, 30)]))
self.assertEqual(12.5, Lgm_CTrans.dateToFPHours(datetime.datetime(2000, 12, 12, 12, 30)))
self.assertEqual(12.25, Lgm_CTrans.dateToFPHours(datetime.datetime(2000, 12, 12, 12, 15)))
self.assertEqual(12.75, Lgm_CTrans.dateToFPHours(datetime.datetime(2000, 12, 12, 12, 45)))
d1 = datetime.datetime(2000, 12, 12, 12, 30)
self.assertEqual([12.5, 12.5], Lgm_CTrans.dateToFPHours([d1, d1]))
self.assertEqual([12.5, 12.5], Lgm_CTrans.dateToFPHours(numpy.array([d1, d1])).tolist())
def getLatLonRadfromTLE(epochs, TLEpath, options):
""" Reads Latitude and Longitude from TLE.
Parameters
==========
epochs :
List of Ticktock objects.
TLEpath :
Path to TLE file.
options : optparse.Values
Organized options from the command line.
Returns
=======
testlat, testlon, testrad : list, list, list
Latitude, Longitude, and Radius, respectively, each being
a list of float values.
"""
# now do Mike's setup for getting coords from TLE using SGP4
pos_in = [0, 0, 0]
s = _SgpInfo()
TLEs = _SgpTLE()
# loop over all times
testlat = np.asarray(epochs).copy()
testlat.fill(0)
testlon = testlat.copy()
testrad = testlat.copy()
testtdiff = testlat.copy()
print('Fetching TLEs & converting for range {0} to {1}'.format(
epochs[0].isoformat(), epochs[-1].isoformat()))
for idx, c_date in enumerate(epochs):
#print('Doing {0}'.format(c_date))
# put into JD as SGP4 needs serial time
c = Lgm_init_ctrans(0)
# now do Mike's setup for getting coords from TLE using SGP4
dstr = int(c_date.strftime('%Y%j')) + c_date.hour / 24.0 + \
c_date.minute / 1440.0 + c_date.second / 86400.0
globstat = os.path.join(TLEpath, '*.txt')
TLEfiles = glob.glob(globstat)
if not TLEfiles:
raise IOError(
'No TLE files found in {0}. Aborting...'.format(TLEpath))
Line0, Line1, Line2 = fTLE.findTLEinfiles(
TLEfiles,
ParseMethod='UseSatelliteNumber',
TargetEpoch=dstr,
SatelliteNumber=options.SatNum,
Verbose=False,
PurgeDuplicates=True)
# print("{0}\n{1}\n{2}\n\n".format(Line0,Line1,Line2))
nTLEs = c_int(0)
LgmSgp_ReadTlesFromStrings(Line0, Line1, Line2, pointer(nTLEs),
pointer(TLEs), 1)
LgmSgp_SGP4_Init(pointer(s), pointer(TLEs))
date = Lgm_CTrans.dateToDateLong(c_date)
utc = Lgm_CTrans.dateToFPHours(c_date)
JD = Lgm_JD(c_date.year, c_date.month, c_date.day, utc,
LGM_TIME_SYS_UTC, c)
# Set up the trans matrices
Lgm_Set_Coord_Transforms(date, utc, c)
# get SGP4 output, needs minutes-since-TLE-epoch
tsince = (JD - TLEs.JD) * 1440.0
LgmSgp_SGP4(tsince, pointer(s))
pos_in[0] = s.X
pos_in[1] = s.Y
pos_in[2] = s.Z
Pin = Lgm_Vector.Lgm_Vector(*pos_in)
Pout = Lgm_Vector.Lgm_Vector()
Lgm_Convert_Coords(pointer(Pin), pointer(Pout), TEME_TO_GEO, c)
PoutPy = Pout.tolist()
PoutPy[0] /= WGS84_A
PoutPy[1] /= WGS84_A
PoutPy[2] /= WGS84_A
nlat, nlon, nrad = Lgm_Vector.CartToSph(*PoutPy)
testlat[idx] = nlat
testlon[idx] = nlon
testrad[idx] = nrad
testtdiff[idx] = tsince / 1440.0
return testlat, testlon, testrad
def getLatLonRadfromTLE(epochs, TLEpath, options):
""" Reads Latitude and Longitude from TLE.
Parameters
==========
epochs :
List of Ticktock objects.
TLEpath :
Path to TLE file.
options : optparse.Values
Organized options from the command line.
Returns
=======
testlat, testlon, testrad : list, list, list
Latitude, Longitude, and Radius, respectively, each being
a list of float values.
"""
# now do Mike's setup for getting coords from TLE using SGP4
pos_in = [0, 0, 0]
s = _SgpInfo()
TLEs = _SgpTLE()
# loop over all times
testlat = np.asarray(epochs).copy()
testlat.fill(0)
testlon = testlat.copy()
testrad = testlat.copy()
testtdiff = testlat.copy()
print('Fetching TLEs & converting for range {0} to {1}'.format(
epochs[0].isoformat(), epochs[-1].isoformat()))
for idx, c_date in enumerate(epochs):
#print('Doing {0}'.format(c_date))
# put into JD as SGP4 needs serial time
c = Lgm_init_ctrans(0)
# now do Mike's setup for getting coords from TLE using SGP4
dstr = int(c_date.strftime('%Y%j')) + c_date.hour / 24.0 + \
c_date.minute / 1440.0 + c_date.second / 86400.0
globstat = os.path.join(TLEpath, '*.txt')
TLEfiles = glob.glob(globstat)
if not TLEfiles:
raise IOError(
'No TLE files found in {0}. Aborting...'.format(TLEpath))
Line0, Line1, Line2 = fTLE.findTLEinfiles(
TLEfiles,
ParseMethod='UseSatelliteNumber',
TargetEpoch=dstr,
SatelliteNumber=options.SatNum,
Verbose=False,
PurgeDuplicates=True)
# print("{0}\n{1}\n{2}\n\n".format(Line0,Line1,Line2))
nTLEs = c_int(0)
LgmSgp_ReadTlesFromStrings(
Line0,
Line1,
Line2,
pointer(nTLEs),
pointer(TLEs),
1)
LgmSgp_SGP4_Init(pointer(s), pointer(TLEs))
date = Lgm_CTrans.dateToDateLong(c_date)
utc = Lgm_CTrans.dateToFPHours(c_date)
JD = Lgm_JD(
c_date.year,
c_date.month,
c_date.day,
utc,
LGM_TIME_SYS_UTC,
c)
# Set up the trans matrices
Lgm_Set_Coord_Transforms(date, utc, c)
# get SGP4 output, needs minutes-since-TLE-epoch
tsince = (JD - TLEs.JD) * 1440.0
LgmSgp_SGP4(tsince, pointer(s))
pos_in[0] = s.X
pos_in[1] = s.Y
pos_in[2] = s.Z
Pin = Lgm_Vector.Lgm_Vector(*pos_in)
Pout = Lgm_Vector.Lgm_Vector()
Lgm_Convert_Coords(pointer(Pin), pointer(Pout), TEME_TO_GEO, c)
PoutPy = Pout.tolist()
PoutPy[0] /= WGS84_A
PoutPy[1] /= WGS84_A
PoutPy[2] /= WGS84_A
nlat, nlon, nrad = Lgm_Vector.CartToSph(*PoutPy)
testlat[idx] = nlat
testlon[idx] = nlon
testrad[idx] = nrad
testtdiff[idx] = tsince / 1440.0
return testlat, testlon, testrad
def coordTrans(pos_in, time_in, in_sys, out_sys, de_eph=False):
'''
Convert coordinates between almost any system using LanlGeoMag
Parameters
----------
position : list
a three element vector of positions in input coord system
time : datetime
a datimetime object representing the time at the desired conversion
system_in : str
a string giving the acronym for the input coordinate system
system_out : str
a string giving the acronym for the desired output coordinate system
de_eph : bool or int (optional)
a boolean stating whether JPL DE421 is to be used for Sun, etc.
Returns
-------
out : list
3-element list of the converted coordinate
Examples
--------
>>> from lgmpy import magcoords
>>> import datetime
>>> magcoords.coordTrans([-4,0,0], datetime.datetime(2009,1,1),'SM','GSM')
[-3.60802691..., 2.5673907444...e-16, -1.72688788616...]
>>> magcoords.coordTrans([-3.608026916281573, 2.5673907444456745e-16, -1.7268878861662329], datetime.datetime(2009,1,1),'GSM','SM')
[-3.99999999..., 4.0592529337...e-16, 8.8817841970...3e-16]
TODO
----
extend interface to get necessary args from a MagModel or cTrans structure
'''
# change datetime to Lgm Datelong and UTC
ct = Lgm_CTrans.Lgm_CTrans(0)
if de_eph:
Lgm_Set_CTrans_Options(LGM_EPH_DE, LGM_PN_IAU76, pointer(ct))
try:
datelong = Lgm_CTrans.dateToDateLong(time_in)
utc = Lgm_CTrans.dateToFPHours(time_in)
Lgm_Set_Coord_Transforms( datelong, utc, pointer(ct)) # don't need pointer as it is one
except AttributeError:
raise(TypeError("Date must be a datetime object"))
try:
conv_val = trans_dict[in_sys]*100 + trans_dict[out_sys]
except KeyError:
raise KeyError('One of the specified coordinate systems is not recognised')
## do this as WGS uses Cartesian but needs to be converted from desired spherical input
if 'WGS84' in in_sys:
XYZ = Lgm_Vector.SphToCart(*pos_in)
SPH = Lgm_Vector.Lgm_Vector(XYZ.x,XYZ.y, XYZ.z)
Pout = _doConversion(SPH, conv_val, cTrans=ct)
else:
Pout = _doConversion(pos_in, conv_val, ct)
if 'WGS84' in out_sys:
nlat, nlon, nrad = Lgm_Vector.CartToSph(*Pout.tolist())
Pout = Lgm_Vector.Lgm_Vector(nlat, nlon, nrad)
return Pout.tolist()
def Lvalue(*args, **kwargs):
'''
Function to return the L-value of a position using either McIlwain or Hilton
approximation
Parameters
==========
pos : list
3-element position int he specified coord_system
time : datetime
date and time for the calculation
alpha : float, optional
the pitch angle for the L calculation, default=90
Bfield : str, optional
the magnetic field model to use, default=Lgm_B_T89
method : str, optional
the L-value formula to use, McIlwain or Hilton, default=Hilton
Kp : int
Kp index value for the calculation
coord_system : str
the input coordinate system, default=GSM
extended_out : bool
keyword specifying short or extended output, default=False
Returns
=======
out : dict
dictionary of the values, see examples for documentation of dictionary
Examples
========
>>> from lgmpy import magcoords
>>> import datetime
>>> magcoords.Lvalue([3, 0, 1], datetime.datetime(2000, 1, 1), extended_out=False)
{'I': 0.2434969602..., 'L': 3.195481841...}
The ``extended_out=False`` output is:
- I : I value at the given point
- L : L value at the given point
>>> from lgmpy import magcoords
>>> import datetime
>>> magcoords.Lvalue([3, 0, 1], datetime.datetime(2000, 1, 1), extended_out=True)
{'Blocal': 1024.1142193703838,
'Bmin': 921.8869150...,
'Bmirr': 1024.1142193...,
'I': 0.24349696021...,
'L': 3.1954818410...,
'M': 30119.614287...}
The ``extended_out=True`` output is:
- I : I value at the given point
- L : L value at the given point
- Bmin : minimum B at the input position (nT)
- Bmirror : mirror B at the input position (nT)
- M : TODO what exactly and I, magnetic moment?
'''
defaults = {'alpha': 90.,
'Bfield': 'Lgm_B_T89',
'method': 'Hilton',
'Kp': 2,
'coord_system': 'GSM',
'extended_out': False}
#replace missing kwargs with defaults
for dkey in defaults:
if dkey not in kwargs:
kwargs[dkey] = defaults[dkey]
method_dict = {'Hilton': 1, 'McIlwain': 0}
# change datetime to Lgm Datelong and UTC
mInfo = Lgm_MagModelInfo.Lgm_MagModelInfo()
mInfo.Kp = kwargs['Kp']
try:
Bfield_dict[kwargs['Bfield']](pointer(mInfo))
except KeyError:
raise(NotImplementedError("Only Bfield=%s currently supported" % Bfield_dict.keys()))
try:
datelong = Lgm_CTrans.dateToDateLong(args[1])
utc = Lgm_CTrans.dateToFPHours(args[1])
Lgm_Set_Coord_Transforms( datelong, utc, mInfo.c) # dont need pointer as it is one
except AttributeError:
raise(TypeError("Date must be a datetime object"))
#else:
#ans['Epoch'] = datamodel.dmarray([args[1]])
if kwargs['coord_system'] != 'GSM':
in_sys = kwargs['coord_system']
Pout = coordTrans(args[0], args[1], in_sys, 'GSM', de_eph=False)
Pgsm = Lgm_Vector.Lgm_Vector(*Pout)
else:
Pgsm = Lgm_Vector.Lgm_Vector(*args[0])
Iout = c_double()
Bm = c_double()
M = c_double()
ans = Lgm_McIlwain_L(datelong, utc, pointer(Pgsm), kwargs['alpha'],
method_dict[kwargs['method']],
pointer(Iout), pointer(Bm), pointer(M),
pointer(mInfo))
#TODO: decide on format for output -- perhaps use datamodel and have method as attribute?
#maybe only return I for extended_out flag=True
if kwargs['extended_out']:
sunPos_GSM = coordTrans(mInfo.c.contents.Sun, args[1], 'MOD', kwargs['coord_system'])
SunMlon = np.rad2deg(np.arctan2( sunPos_GSM[1], sunPos_GSM[0]))
SunMlon += 180.0 # flip to midnight
MLON = np.rad2deg(np.arctan2( Pgsm.y, Pgsm.x))
if (MLON < 0.0):
MLON += 360.0
MLT = np.mod( (MLON-SunMlon)/15.0+24.0, 24.0 )
return {'L': ans, 'I': Iout.value, 'Bmin': mInfo.Bmin, 'Blocal': mInfo.Blocal,
'Bmirr': mInfo.Bm, 'M': M.value, 'MLon':MLON, 'MLT':MLT}
else:
return {'L': ans, 'I': Iout.value}
def coordTrans(pos_in, time_in, in_sys, out_sys, de_eph=False):
'''
Convert coordinates between almost any system using LanlGeoMag
Parameters
----------
position : list
a three element vector of positions in input coord system
time : datetime
a datimetime object representing the time at the desired conversion
system_in : str
a string giving the acronym for the input coordinate system
system_out : str
a string giving the acronym for the desired output coordinate system
de_eph : bool or int (optional)
a boolean stating whether JPL DE421 is to be used for Sun, etc.
Returns
-------
out : list
3-element list of the converted coordinate
Examples
--------
>>> from lgmpy import magcoords
>>> import datetime
>>> magcoords.coordTrans([-4,0,0], datetime.datetime(2009,1,1),'SM','GSM')
[-3.60802691..., 2.5673907444...e-16, -1.72688788616...]
>>> magcoords.coordTrans([-3.608026916281573, 2.5673907444456745e-16, -1.7268878861662329], datetime.datetime(2009,1,1),'GSM','SM')
[-3.99999999..., 4.0592529337...e-16, 8.8817841970...3e-16]
TODO
----
extend interface to get necessary args from a MagModel or cTrans structure
'''
# change datetime to Lgm Datelong and UTC
ct = Lgm_CTrans.Lgm_CTrans(0)
if de_eph:
Lgm_Set_CTrans_Options(LGM_EPH_DE, LGM_PN_IAU76, pointer(ct))
try:
datelong = Lgm_CTrans.dateToDateLong(time_in)
utc = Lgm_CTrans.dateToFPHours(time_in)
Lgm_Set_Coord_Transforms(
datelong, utc, pointer(ct)) # don't need pointer as it is one
except AttributeError:
raise (TypeError("Date must be a datetime object"))
try:
conv_val = trans_dict[in_sys] * 100 + trans_dict[out_sys]
except KeyError:
raise KeyError(
'One of the specified coordinate systems is not recognised')
## do this as WGS uses Cartesian but needs to be converted from desired spherical input
if 'WGS84' in in_sys:
XYZ = Lgm_Vector.SphToCart(*pos_in)
SPH = Lgm_Vector.Lgm_Vector(XYZ.x, XYZ.y, XYZ.z)
Pout = _doConversion(SPH, conv_val, cTrans=ct)
else:
Pout = _doConversion(pos_in, conv_val, ct)
if 'WGS84' in out_sys:
nlat, nlon, nrad = Lgm_Vector.CartToSph(*Pout.tolist())
Pout = Lgm_Vector.Lgm_Vector(nlat, nlon, nrad)
return Pout.tolist()
def Lvalue(*args, **kwargs):
'''
Function to return the L-value of a position using either McIlwain or Hilton
approximation
Parameters
==========
pos : list
3-element position int he specified coord_system
time : datetime
date and time for the calculation
alpha : float, optional
the pitch angle for the L calculation, default=90
Bfield : str, optional
the magnetic field model to use, default=Lgm_B_T89
method : str, optional
the L-value formula to use, McIlwain or Hilton, default=Hilton
Kp : int
Kp index value for the calculation
coord_system : str
the input coordinate system, default=GSM
extended_out : bool
keyword specifying short or extended output, default=False
Returns
=======
out : dict
dictionary of the values, see examples for documentation of dictionary
Examples
========
>>> from lgmpy import magcoords
>>> import datetime
>>> magcoords.Lvalue([3, 0, 1], datetime.datetime(2000, 1, 1), extended_out=False)
{'I': 0.2434969602..., 'L': 3.195481841...}
The ``extended_out=False`` output is:
- I : I value at the given point
- L : L value at the given point
>>> from lgmpy import magcoords
>>> import datetime
>>> magcoords.Lvalue([3, 0, 1], datetime.datetime(2000, 1, 1), extended_out=True)
{'Blocal': 1024.1142193703838,
'Bmin': 921.8869150...,
'Bmirr': 1024.1142193...,
'I': 0.24349696021...,
'L': 3.1954818410...,
'M': 30119.614287...}
The ``extended_out=True`` output is:
- I : I value at the given point
- L : L value at the given point
- Bmin : minimum B at the input position (nT)
- Bmirror : mirror B at the input position (nT)
- M : TODO what exactly and I, magnetic moment?
'''
defaults = {
'alpha': 90.,
'Bfield': 'Lgm_B_T89',
'method': 'Hilton',
'Kp': 2,
'coord_system': 'GSM',
'extended_out': False
}
#replace missing kwargs with defaults
for dkey in defaults:
if dkey not in kwargs:
kwargs[dkey] = defaults[dkey]
method_dict = {'Hilton': 1, 'McIlwain': 0}
# change datetime to Lgm Datelong and UTC
mInfo = Lgm_MagModelInfo.Lgm_MagModelInfo()
mInfo.Kp = kwargs['Kp']
try:
Bfield_dict[kwargs['Bfield']](pointer(mInfo))
except KeyError:
raise (NotImplementedError("Only Bfield=%s currently supported" %
Bfield_dict.keys()))
try:
datelong = Lgm_CTrans.dateToDateLong(args[1])
utc = Lgm_CTrans.dateToFPHours(args[1])
Lgm_Set_Coord_Transforms(datelong, utc,
mInfo.c) # dont need pointer as it is one
except AttributeError:
raise (TypeError("Date must be a datetime object"))
#else:
#ans['Epoch'] = datamodel.dmarray([args[1]])
if kwargs['coord_system'] != 'GSM':
in_sys = kwargs['coord_system']
Pout = coordTrans(args[0], args[1], in_sys, 'GSM', de_eph=False)
Pgsm = Lgm_Vector.Lgm_Vector(*Pout)
else:
Pgsm = Lgm_Vector.Lgm_Vector(*args[0])
Iout = c_double()
Bm = c_double()
M = c_double()
ans = Lgm_McIlwain_L(datelong, utc, pointer(Pgsm), kwargs['alpha'],
method_dict[kwargs['method']], pointer(Iout),
pointer(Bm), pointer(M), pointer(mInfo))
#TODO: decide on format for output -- perhaps use datamodel and have method as attribute?
#maybe only return I for extended_out flag=True
if kwargs['extended_out']:
sunPos_GSM = coordTrans(mInfo.c.contents.Sun, args[1], 'MOD',
kwargs['coord_system'])
SunMlon = np.rad2deg(np.arctan2(sunPos_GSM[1], sunPos_GSM[0]))
SunMlon += 180.0 # flip to midnight
MLON = np.rad2deg(np.arctan2(Pgsm.y, Pgsm.x))
if (MLON < 0.0):
MLON += 360.0
MLT = np.mod((MLON - SunMlon) / 15.0 + 24.0, 24.0)
return {
'L': ans,
'I': Iout.value,
'Bmin': mInfo.Bmin,
'Blocal': mInfo.Blocal,
'Bmirr': mInfo.Bm,
'M': M.value,
'MLon': MLON,
'MLT': MLT
}
else:
return {'L': ans, 'I': Iout.value}
