def test_premat(self):
fn = "premat.test"
good, dat = self.getData(fn)
self.assertEqual(good, True)
err = 0
for i in xrange(len(dat[::,0])):
r = numpy.reshape(dat[i,2:11], (3,3))
if dat[i,11] == 0:
m = at.premat(dat[i,0], dat[i,1])
else:
m = at.premat(dat[i,0], dat[i,1], FK4=True)
if (r-m).max() > self.p:
print "test_premat - Error detected"
err += 1
self.assertEqual(err, 0)
def baryvel(dje, deq):
"""
Calculate helio- and barycentric velocity.
.. note:: The "JPL" option present in IDL is not provided here.
Parameters
----------
dje : float
Julian ephemeris date
deq : float
Epoch of mean equinox of helio- and barycentric velocity output.
If `deq` is zero, `deq` is assumed to be equal to `dje`.
Returns
-------
dvelh : array
Heliocentric velocity vector [km/s].
dvelb : array
Barycentric velocity vector [km/s].
Notes
-----
.. note:: This function was ported from the IDL Astronomy User's Library.
:IDL - Documentation:
pro baryvel, dje, deq, dvelh, dvelb, JPL = JPL
NAME:
BARYVEL
PURPOSE:
Calculates heliocentric and barycentric velocity components of Earth.
EXPLANATION:
BARYVEL takes into account the Earth-Moon motion, and is useful for
radial velocity work to an accuracy of ~1 m/s.
CALLING SEQUENCE:
BARYVEL, dje, deq, dvelh, dvelb, [ JPL = ]
INPUTS:
DJE - (scalar) Julian ephemeris date.
DEQ - (scalar) epoch of mean equinox of dvelh and dvelb. If deq=0
then deq is assumed to be equal to dje.
OUTPUTS:
DVELH: (vector(3)) heliocentric velocity component. in km/s
DVELB: (vector(3)) barycentric velocity component. in km/s
The 3-vectors DVELH and DVELB are given in a right-handed coordinate
system with the +X axis toward the Vernal Equinox, and +Z axis
toward the celestial pole.
OPTIONAL KEYWORD SET:
JPL - if /JPL set, then BARYVEL will call the procedure JPLEPHINTERP
to compute the Earth velocity using the full JPL ephemeris.
The JPL ephemeris FITS file JPLEPH.405 must exist in either the
current directory, or in the directory specified by the
environment variable ASTRO_DATA. Alternatively, the JPL keyword
can be set to the full path and name of the ephemeris file.
A copy of the JPL ephemeris FITS file is available in
http://idlastro.gsfc.nasa.gov/ftp/data/
PROCEDURES CALLED:
Function PREMAT() -- computes precession matrix
JPLEPHREAD, JPLEPHINTERP, TDB2TDT - if /JPL keyword is set
NOTES:
Algorithm taken from FORTRAN program of Stumpff (1980, A&A Suppl, 41,1)
Stumpf claimed an accuracy of 42 cm/s for the velocity. A
comparison with the JPL FORTRAN planetary ephemeris program PLEPH
found agreement to within about 65 cm/s between 1986 and 1994
If /JPL is set (using JPLEPH.405 ephemeris file) then velocities are
given in the ICRS system; otherwise in the FK4 system.
EXAMPLE:
Compute the radial velocity of the Earth toward Altair on 15-Feb-1994
using both the original Stumpf algorithm and the JPL ephemeris
IDL> jdcnv, 1994, 2, 15, 0, jd ;==> JD = 2449398.5
IDL> baryvel, jd, 2000, vh, vb ;Original algorithm
==> vh = [-17.07243, -22.81121, -9.889315] ;Heliocentric km/s
==> vb = [-17.08083, -22.80471, -9.886582] ;Barycentric km/s
IDL> baryvel, jd, 2000, vh, vb, /jpl ;JPL ephemeris
==> vh = [-17.07236, -22.81126, -9.889419] ;Heliocentric km/s
==> vb = [-17.08083, -22.80484, -9.886409] ;Barycentric km/s
IDL> ra = ten(19,50,46.77)*15/!RADEG ;RA in radians
IDL> dec = ten(08,52,3.5)/!RADEG ;Dec in radians
IDL> v = vb[0]*cos(dec)*cos(ra) + $ ;Project velocity toward star
vb[1]*cos(dec)*sin(ra) + vb[2]*sin(dec)
REVISION HISTORY:
Jeff Valenti, U.C. Berkeley Translated BARVEL.FOR to IDL.
W. Landsman, Cleaned up program sent by Chris McCarthy (SfSU) June 1994
Converted to IDL V5.0 W. Landsman September 1997
Added /JPL keyword W. Landsman July 2001
Documentation update W. Landsman Dec 2005
"""
# Define constants
dc2pi = 2 * np.pi
cc2pi = 2 * np.pi
dc1 = 1.0
dcto = 2415020.0
dcjul = 36525.0 # days in Julian year
dcbes = 0.313
dctrop = 365.24219572 # days in tropical year (...572 insig)
dc1900 = 1900.0
AU = 1.4959787e8
# Constants dcfel(i,k) of fast changing elements.
dcfel = [1.7400353e00, 6.2833195099091e02, 5.2796e-6 \
,6.2565836e00, 6.2830194572674e02, -2.6180e-6 \
,4.7199666e00, 8.3997091449254e03, -1.9780e-5 \
,1.9636505e-1, 8.4334662911720e03, -5.6044e-5 \
,4.1547339e00, 5.2993466764997e01, 5.8845e-6 \
,4.6524223e00, 2.1354275911213e01, 5.6797e-6 \
,4.2620486e00, 7.5025342197656e00, 5.5317e-6 \
,1.4740694e00, 3.8377331909193e00, 5.6093e-6 ]
dcfel = np.resize(dcfel, (8,3))
# constants dceps and ccsel(i,k) of slowly changing elements.
dceps = [4.093198e-1, -2.271110e-4, -2.860401e-8 ]
ccsel = [1.675104e-2, -4.179579e-5, -1.260516e-7 \
,2.220221e-1, 2.809917e-2, 1.852532e-5 \
,1.589963e00, 3.418075e-2, 1.430200e-5 \
,2.994089e00, 2.590824e-2, 4.155840e-6 \
,8.155457e-1, 2.486352e-2, 6.836840e-6 \
,1.735614e00, 1.763719e-2, 6.370440e-6 \
,1.968564e00, 1.524020e-2, -2.517152e-6 \
,1.282417e00, 8.703393e-3, 2.289292e-5 \
,2.280820e00, 1.918010e-2, 4.484520e-6 \
,4.833473e-2, 1.641773e-4, -4.654200e-7 \
,5.589232e-2, -3.455092e-4, -7.388560e-7 \
,4.634443e-2, -2.658234e-5, 7.757000e-8 \
,8.997041e-3, 6.329728e-6, -1.939256e-9 \
,2.284178e-2, -9.941590e-5, 6.787400e-8 \
,4.350267e-2, -6.839749e-5, -2.714956e-7 \
,1.348204e-2, 1.091504e-5, 6.903760e-7 \
,3.106570e-2, -1.665665e-4, -1.590188e-7 ]
ccsel = np.resize(ccsel, (17,3))
# Constants of the arguments of the short-period perturbations.
dcargs = [5.0974222e0, -7.8604195454652e2 \
,3.9584962e0, -5.7533848094674e2 \
,1.6338070e0, -1.1506769618935e3 \
,2.5487111e0, -3.9302097727326e2 \
,4.9255514e0, -5.8849265665348e2 \
,1.3363463e0, -5.5076098609303e2 \
,1.6072053e0, -5.2237501616674e2 \
,1.3629480e0, -1.1790629318198e3 \
,5.5657014e0, -1.0977134971135e3 \
,5.0708205e0, -1.5774000881978e2 \
,3.9318944e0, 5.2963464780000e1 \
,4.8989497e0, 3.9809289073258e1 \
,1.3097446e0, 7.7540959633708e1 \
,3.5147141e0, 7.9618578146517e1 \
,3.5413158e0, -5.4868336758022e2 ]
dcargs = np.resize(dcargs, (15,2))
# Amplitudes ccamps(n,k) of the short-period perturbations.
ccamps = \
[-2.279594e-5, 1.407414e-5, 8.273188e-6, 1.340565e-5, -2.490817e-7 \
,-3.494537e-5, 2.860401e-7, 1.289448e-7, 1.627237e-5, -1.823138e-7 \
, 6.593466e-7, 1.322572e-5, 9.258695e-6, -4.674248e-7, -3.646275e-7 \
, 1.140767e-5, -2.049792e-5, -4.747930e-6, -2.638763e-6, -1.245408e-7 \
, 9.516893e-6, -2.748894e-6, -1.319381e-6, -4.549908e-6, -1.864821e-7 \
, 7.310990e-6, -1.924710e-6, -8.772849e-7, -3.334143e-6, -1.745256e-7 \
,-2.603449e-6, 7.359472e-6, 3.168357e-6, 1.119056e-6, -1.655307e-7 \
,-3.228859e-6, 1.308997e-7, 1.013137e-7, 2.403899e-6, -3.736225e-7 \
, 3.442177e-7, 2.671323e-6, 1.832858e-6, -2.394688e-7, -3.478444e-7 \
, 8.702406e-6, -8.421214e-6, -1.372341e-6, -1.455234e-6, -4.998479e-8 \
,-1.488378e-6, -1.251789e-5, 5.226868e-7, -2.049301e-7, 0.e0 \
,-8.043059e-6, -2.991300e-6, 1.473654e-7, -3.154542e-7, 0.e0 \
, 3.699128e-6, -3.316126e-6, 2.901257e-7, 3.407826e-7, 0.e0 \
, 2.550120e-6, -1.241123e-6, 9.901116e-8, 2.210482e-7, 0.e0 \
,-6.351059e-7, 2.341650e-6, 1.061492e-6, 2.878231e-7, 0.e0 ]
ccamps = np.resize(ccamps, (15,5))
# Constants csec3 and ccsec(n,k) of the secular perturbations in longitude.
ccsec3 = -7.757020e-8
ccsec = [1.289600e-6, 5.550147e-1, 2.076942e00 \
,3.102810e-5, 4.035027e00, 3.525565e-1 \
,9.124190e-6, 9.990265e-1, 2.622706e00 \
,9.793240e-7, 5.508259e00, 1.559103e01 ]
ccsec = np.resize(ccsec, (4,3))
# Sidereal rates.
dcsld = 1.990987e-7 # sidereal rate in longitude
ccsgd = 1.990969e-7 # sidereal rate in mean anomaly
# Constants used in the calculation of the lunar contribution.
cckm = 3.122140e-5
ccmld = 2.661699e-6
ccfdi = 2.399485e-7
# Constants dcargm(i,k) of the arguments of the perturbations of the motion
# of the moon.
dcargm = [5.1679830e0, 8.3286911095275e3 \
,5.4913150e0, -7.2140632838100e3 \
,5.9598530e0, 1.5542754389685e4 ]
dcargm = np.resize(dcargm, (3,2))
# Amplitudes ccampm(n,k) of the perturbations of the moon.
ccampm = [ 1.097594e-1, 2.896773e-7, 5.450474e-2, 1.438491e-7 \
,-2.223581e-2, 5.083103e-8, 1.002548e-2, -2.291823e-8 \
, 1.148966e-2, 5.658888e-8, 8.249439e-3, 4.063015e-8 ]
ccampm = np.resize(ccampm, (3,4))
# ccpamv(k)=a*m*dl,dt (planets), dc1mme=1-mass(earth+moon)
ccpamv = [8.326827e-11, 1.843484e-11, 1.988712e-12, 1.881276e-12]
dc1mme = 0.99999696e0
# Time arguments.
dt = (dje - dcto) / dcjul
tvec = np.array([1e0, dt, dt*dt])
# Values of all elements for the instant(aneous?) dje.
temp = idlMod(np.dot(dcfel, tvec), dc2pi)
dml = temp[0]
forbel = temp[1:8]
g = forbel[0] # old fortran equivalence
deps = idlMod(np.sum(tvec*dceps), dc2pi)
sorbel = idlMod(np.dot(ccsel, tvec), dc2pi)
e = sorbel[0] # old fortran equivalence
# Secular perturbations in longitude.
dummy = np.cos(2.0)
sn = np.sin(idlMod(np.dot(ccsec[::,1:3], tvec[0:2]), cc2pi))
# Periodic perturbations of the emb (earth-moon barycenter).
pertl = np.sum(ccsec[::,0] * sn) + (dt * ccsec3 * sn[2])
pertld = 0.0
pertr = 0.0
pertrd = 0.0
for k in xrange(15):
a = idlMod((dcargs[k,0] + dt*dcargs[k,1]), dc2pi)
cosa = np.cos(a)
sina = np.sin(a)
pertl = pertl + ccamps[k,0]*cosa + ccamps[k,1]*sina
pertr = pertr + ccamps[k,2]*cosa + ccamps[k,3]*sina
if k < 11:
pertld = pertld + (ccamps[k,1]*cosa-ccamps[k,0]*sina)*ccamps[k,4]
pertrd = pertrd + (ccamps[k,3]*cosa-ccamps[k,2]*sina)*ccamps[k,4]
# Elliptic part of the motion of the emb.
phi = (e*e/4e0)*(((8e0/e)-e)*np.sin(g) +5*np.sin(2*g) +(13/3e0)*e*np.sin(3*g))
f = g + phi
sinf = np.sin(f)
cosf = np.cos(f)
dpsi = (dc1 - e*e) / (dc1 + e*cosf)
phid = 2*e*ccsgd*((1 + 1.5*e*e)*cosf + e*(1.25 - 0.5*sinf*sinf))
psid = ccsgd*e*sinf / np.sqrt(dc1 - e*e)
# Perturbed heliocentric motion of the emb.
d1pdro = dc1+pertr
drd = d1pdro * (psid + dpsi*pertrd)
drld = d1pdro*dpsi * (dcsld+phid+pertld)
dtl = idlMod((dml + phi + pertl), dc2pi)
dsinls = np.sin(dtl)
dcosls = np.cos(dtl)
dxhd = drd*dcosls - drld*dsinls
dyhd = drd*dsinls + drld*dcosls
# Influence of eccentricity, evection and variation on the geocentric
# motion of the moon.
pertl = 0.0
pertld = 0.0
pertp = 0.0
pertpd = 0.0
for k in xrange(3):
a = idlMod((dcargm[k,0] + dt*dcargm[k,1]), dc2pi)
sina = np.sin(a)
cosa = np.cos(a)
pertl = pertl + ccampm[k,0]*sina
pertld = pertld + ccampm[k,1]*cosa
pertp = pertp + ccampm[k,2]*cosa
pertpd = pertpd - ccampm[k,3]*sina
# Heliocentric motion of the earth.
tl = forbel[1] + pertl
sinlm = np.sin(tl)
coslm = np.cos(tl)
sigma = cckm / (1.0 + pertp)
a = sigma*(ccmld + pertld)
b = sigma*pertpd
dxhd = dxhd + a*sinlm + b*coslm
dyhd = dyhd - a*coslm + b*sinlm
dzhd= -sigma*ccfdi*np.cos(forbel[2])
# Barycentric motion of the earth.
dxbd = dxhd*dc1mme
dybd = dyhd*dc1mme
dzbd = dzhd*dc1mme
for k in xrange(4):
plon = forbel[k+3]
pomg = sorbel[k+1]
pecc = sorbel[k+9]
tl = idlMod((plon + 2.0*pecc*np.sin(plon-pomg)), cc2pi)
dxbd = dxbd + ccpamv[k]*(np.sin(tl) + pecc*np.sin(pomg))
dybd = dybd - ccpamv[k]*(np.cos(tl) + pecc*np.cos(pomg))
dzbd = dzbd - ccpamv[k]*sorbel[k+13]*np.cos(plon - sorbel[k+5])
# Transition to mean equator of date.
dcosep = np.cos(deps)
dsinep = np.sin(deps)
dyahd = dcosep*dyhd - dsinep*dzhd
dzahd = dsinep*dyhd + dcosep*dzhd
dyabd = dcosep*dybd - dsinep*dzbd
dzabd = dsinep*dybd + dcosep*dzbd
# Epoch of mean equinox (deq) of zero implies that we should use
# Julian ephemeris date (dje) as epoch of mean equinox.
if deq == 0:
dvelh = AU * np.array([dxhd, dyahd, dzahd])
dvelb = AU * np.array([dxbd, dyabd, dzabd])
return dvelh, dvelb
# General precession from epoch dje to deq.
deqdat = (dje-dcto-dcbes) / dctrop + dc1900
prema = np.transpose(premat(deqdat, deq, FK4=True))
dvelh = AU * np.dot( [dxhd, dyahd, dzahd], prema )
dvelb = AU * np.dot( [dxbd, dyabd, dzabd], prema )
return dvelh, dvelb
