def extrapolate_sp3_DataFrame(DFsp3,
step=900,
n_step=9,
backward=True,
forward=True,
until_backward=None,
until_forward=None,
return_all=True):
"""
Extrapolate the positions in a SP3 based on the first/last
epochs' position
Parameters
----------
DFsp3 : DataFrame
Input Orbit DataFrame (i.e. generated by files_rw.read_sp3).
step : int, optional
step between two epochs. The default is 900.
n_step : int, optional
number of epochs to interpolate. The default is 9.
backward and forward : bool, optional
extrapolate for the day before/after. The default is True.
return_all : bool, optional
if True, returns the input DF enhanced with the extrapolated values
if False, returns only the extrapolated values.
The default is True.
until_backward & until_backward : datetime, optional
epoch until then the extrapolation has to be done.
Override n_step
Returns
-------
DForb_out : DataFrame
Orbit DataFrame with extrapolated values
(see return_all).
"""
NewEpoch_stk = []
for sat in DFsp3["sat"].unique():
print("INFO:extrapolate_sp3_DataFrame: extrapolate: ", sat)
DFsat = DFsp3[(DFsp3["sat"] == sat) & (DFsp3["type"] == "P")].copy()
DFsat.sort_values("epoch", inplace=True)
DFline_dummy = DFsat.iloc[0].copy()
DFline_dummy["clk"] = 999999.999999
XYZ = DFsat[["x", "y", "z"]].values * 1000
Tgps = conv.numpy_dt2dt(DFsat["epoch"].values)
Tutc = conv.dt_gpstime2dt_utc(Tgps)
Tsec = [e.total_seconds() for e in (Tutc - Tutc[0])]
P = conv.ECEF2ECI(XYZ, Tutc)
V = np.gradient(P, Tsec, axis=0)
def extrapo_intern_fct(i_ref, coef, until):
##
## backward :
## i_ref , coef = 0,-1
##
## forward :
## i_ref , coef = -1,1
##
## CORRDS ARE GIVEN IN ECI HERE !!!
##
orbit_back = TwoBodyOrbit("orbit",
mu=3.9860044188e14) # create an instance
orbit_back.setOrbCart(Tsec[i_ref], P[i_ref],
V[i_ref]) # define the orbit
if until:
t_rang_strt, t_rang_end = list(sorted([Tutc[i_ref], until]))
Range = conv.dt_range(t_rang_strt, t_rang_end, 0, step)
n_step_intern = len(Range) - 1
else:
n_step_intern = n_step
for t in np.arange(step, n_step_intern * step + 1, step):
Pout, Vout = orbit_back.posvelatt(coef * t)
epoc = Tgps[i_ref] + coef * dt.timedelta(seconds=int(t))
DFline_new = DFline_dummy.copy()
DFline_new[["x", "y", "z"]] = Pout
DFline_new["epoch"] = pd.Timestamp(epoc)
NewEpoch_stk.append(DFline_new)
return Pout, Vout
### backward
if backward:
extrapo_intern_fct(0, -1, until_backward)
### forward
if forward:
extrapo_intern_fct(-1, 1, until_forward)
DFNewEpoch = pd.DataFrame(NewEpoch_stk)
Tutc_NewEpoch = conv.dt_gpstime2dt_utc(
conv.numpy_dt2dt(DFNewEpoch["epoch"].values))
DFNewEpoch[["x", "y",
"z"]] = conv.ECI2ECEF(DFNewEpoch[["x", "y", "z"]].values,
Tutc_NewEpoch)
DFNewEpoch[["x", "y", "z"]] = DFNewEpoch[["x", "y", "z"]] * 10**-3
if return_all:
DForb_out = pd.concat((DFsp3, DFNewEpoch))
else:
DForb_out = DFNewEpoch
DForb_out.reset_index(drop=True, inplace=True)
DForb_out.sort_values(["sat", "epoch"], inplace=True)
DForb_out.reset_index(drop=True, inplace=True)
return DForb_out
def write_sp3(SP3_DF_in,
outpath,
outname=None,
prefix='orb',
skip_null_epoch=True,
force_format_c=False):
"""
Write a SP3 file from an Orbit DataFrame
Parameters
----------
SP3_DF_in : DataFrame
Input Orbit DataFrame.
outpath : str
The output path of the file (see also outname).
outname : None or str, optional
None = outpath is the full path (directory + filename) of the output.
A string = a manual name for the file.
'auto_old_cnv' = automatically generate the filename (old convention)
'auto_new_cnv' = automatically generate the filename (new convention)
The default is None.
prefix : str, optional
the output 3-char. name of the AC. The default is 'orb'.
skip_null_epoch : bool, optional
Do not write an epoch if all sats are null (filtering).
The default is True.
force_format_c : bool, optional
DESCRIPTION. The default is False.
Returns
-------
The string containing the formatted SP3 data.
"""
################## MAIN DATA
LinesStk = []
SP3_DF_wrk = SP3_DF_in.sort_values(["epoch", "sat"])
EpochRawList = SP3_DF_wrk["epoch"].unique()
SatList = sorted(SP3_DF_wrk["sat"].unique())
SatList = list(reversed(SatList))
SatListSet = set(SatList)
EpochUsedList = []
if not "clk" in SP3_DF_wrk.columns:
SP3_DF_wrk["clk"] = 999999.999999
for epoc in EpochRawList:
SP3epoc = pd.DataFrame(SP3_DF_wrk[SP3_DF_wrk["epoch"] == epoc])
## manage missing Sats for the current epoc
MissingSats = SatListSet.difference(set(SP3epoc["sat"]))
for miss_sat in MissingSats:
miss_line = SP3epoc.iloc[0].copy()
miss_line["sat"] = miss_sat
miss_line["const"] = miss_sat[0]
miss_line["x"] = 0.000000
miss_line["y"] = 0.000000
miss_line["z"] = 0.000000
miss_line["clk"] = 999999.999999
SP3epoc = SP3epoc.append(miss_line)
#### end of missing sat bloc
SP3epoc.sort_values("sat", inplace=True, ascending=False)
timestamp = conv.dt2sp3_timestamp(conv.numpy_dt2dt(epoc)) + "\n"
linefmt = "P{:}{:14.6f}{:14.6f}{:14.6f}{:14.6f}\n"
LinesStkEpoch = []
sum_val_epoch = 0
for ilin, lin in SP3epoc.iterrows():
if not "clk" in lin.index: # manage case if no clk in columns
lin["clk"] = 999999.999999
line_out = linefmt.format(lin["sat"], lin["x"], lin["y"], lin["z"],
lin["clk"])
sum_val_epoch += lin["x"] + lin["y"] + lin["z"]
LinesStkEpoch.append(line_out)
### if skip_null_epoch activated, print only if valid epoch
if not (np.isclose(sum_val_epoch, 0) and skip_null_epoch):
LinesStk.append(timestamp) # stack the timestamp
LinesStk = LinesStk + LinesStkEpoch # stack the values
EpochUsedList.append(epoc) # stack the epoc as dt
################## HEADER
######### SATELLITE LIST
Satline_stk = []
Sigmaline_stk = []
if force_format_c:
nlines = 5
else:
div, mod = np.divmod(len(SatList), 17)
if div < 5:
nlines = 5
else:
nlines = div
if mod != 0:
nlines += 1
for i in range(nlines):
SatLine = SatList[17 * i:17 * (i + 1)]
SatLineSigma = len(SatLine) * " 01"
if len(SatLine) < 17:
complem = " 00" * (17 - len(SatLine))
else:
complem = ""
if i == 0:
nbsat4line = len(SatList)
else:
nbsat4line = ''
satline = "+ {:3} ".format(nbsat4line) + "".join(
SatLine) + complem + "\n"
sigmaline = "++ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0\n"
sigmaline = "++ " + SatLineSigma + complem + "\n"
Satline_stk.append(satline)
Sigmaline_stk.append(sigmaline)
######### 2 First LINES
start_dt = conv.numpy_dt2dt(np.min(EpochUsedList))
header_line1 = "#cP" + conv.dt2sp3_timestamp(
start_dt, False) + " {:3}".format(
len(EpochUsedList)) + " u+U IGSXX FIT XXX\n"
delta_epoch = int(utils.most_common(np.diff(EpochUsedList) * 10**-9))
MJD = conv.dt2MJD(start_dt)
MJD_int = int(np.floor(MJD))
MJD_dec = MJD - MJD_int
gps_wwww, gps_sec = conv.dt2gpstime(start_dt, False, "gps")
header_line2 = "## {:4} {:15.8f} {:14.8f} {:5} {:15.13f}\n".format(
gps_wwww, gps_sec, delta_epoch, MJD_int, MJD_dec)
######### HEADER BOTTOM
header_bottom = """%c M cc GPS ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
%c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
%f 1.2500000 1.025000000 0.00000000000 0.000000000000000
%f 0.0000000 0.000000000 0.00000000000 0.000000000000000
%i 0 0 0 0 0 0 0 0 0
%i 0 0 0 0 0 0 0 0 0
/* PCV:IGSXX_XXXX OL/AL:FESXXXX NONE YN CLK:CoN ORB:CoN
/* GeodeZYX Toolbox Output
/*
/*
"""
################## FINAL STACK
FinalLinesStk = []
FinalLinesStk.append(header_line1)
FinalLinesStk.append(header_line2)
FinalLinesStk = FinalLinesStk + Satline_stk + Sigmaline_stk
FinalLinesStk.append(header_bottom)
FinalLinesStk = FinalLinesStk + LinesStk + ["EOF"]
FinalStr = "".join(FinalLinesStk)
### Manage the file path
prefix_opera = prefix
if not outname:
outpath_opera = outpath
elif outname == 'auto_old_cnv':
week, dow = conv.dt2gpstime(start_dt)
filename = prefix_opera + str(week) + str(dow) + '.sp3'
outpath_opera = os.path.join(outpath, filename)
elif outname == 'auto_new_cnv':
print("ERR: not implemented yet !!!!!")
raise Exception
F = open(outpath_opera, "w+")
F.write(FinalStr)