jaxpint.constants#
Physical, astronomical, and model-specific constants for JaxPINT.
- jaxpint.constants.PLANET_MASSES: dict[str, float] = {'jupiter': 4.702819050227708e-09, 'neptune': 2.5373119991867603e-10, 'saturn': 1.408128810019423e-09, 'uranus': 2.1505895513637613e-10, 'venus': 1.205680558494223e-11}#
T_planet = T_sun / mass_ratio (s)
- Type:
Planet mass parameters
- jaxpint.constants.PLANET_NAMES: tuple[str, ...] = ('jupiter', 'saturn', 'venus', 'uranus', 'neptune')#
Names of planets used in Shapiro delay calculation
- jaxpint.constants.OBLIQUITY_ARCSEC: dict[str, float] = {'DE403': 84381.412, 'DEFAULT': 84381.406, 'IAU1976': 84381.448, 'IAU2005': 84381.406, 'IERS1992': 84381.412, 'IERS2003': 84381.4059, 'IERS2010': 84381.406}#
Ecliptic obliquity (arcseconds), from PINT’s ecliptic.dat
- jaxpint.constants.DMCONST: float = 4149.377593360996#
Dispersion constant (MHz^2 * s * cm^3 / pc).
delay = DM * DMCONST / freq_MHz^2. See Lorimer & Kramer, Handbook of Pulsar Astronomy, 2nd ed., p. 86 note 1.
- jaxpint.constants.NIELL_LAT_BREAKS = Array([0. , 0.26179939, 0.52359878, 0.78539816, 1.04719755, 1.30899694, 1.57079633], dtype=float64)#
[0, 15, 30, 45, 60, 75, 90] degrees. Indices 0 and 6 are copies of 1 and 5 for constant extrapolation.
- Type:
Latitude breakpoints (radians)
- jaxpint.constants.NIELL_A_AVG = Array([0.00127699, 0.00127699, 0.00126832, 0.00124654, 0.0012196 , 0.0012046 , 0.0012046 ], dtype=float64)#
Hydrostatic average coefficient a (Niell 1996, Table 1)
- jaxpint.constants.NIELL_B_AVG = Array([0.00291537, 0.00291537, 0.00291523, 0.00292884, 0.00290226, 0.00290249, 0.00290249], dtype=float64)#
Hydrostatic average coefficient b (Niell 1996, Table 1)
- jaxpint.constants.NIELL_C_AVG = Array([0.06261051, 0.06261051, 0.06283739, 0.06372177, 0.06382427, 0.06425846, 0.06425846], dtype=float64)#
Hydrostatic average coefficient c (Niell 1996, Table 1)
- jaxpint.constants.NIELL_A_AMP = Array([0.0000000e+00, 0.0000000e+00, 1.2709626e-05, 2.6523662e-05, 3.4000452e-05, 4.1202191e-05, 4.1202191e-05], dtype=float64)#
Hydrostatic amplitude coefficient a (Niell 1996, Table 3)
- jaxpint.constants.NIELL_B_AMP = Array([0.0000000e+00, 0.0000000e+00, 2.1414979e-05, 3.0160779e-05, 7.2562722e-05, 1.1723375e-04, 1.1723375e-04], dtype=float64)#
Hydrostatic amplitude coefficient b (Niell 1996, Table 3)
- jaxpint.constants.NIELL_C_AMP = Array([0.0000000e+00, 0.0000000e+00, 9.0128400e-05, 4.3497037e-05, 8.4795348e-04, 1.7037206e-03, 1.7037206e-03], dtype=float64)#
Hydrostatic amplitude coefficient c (Niell 1996, Table 3)
- jaxpint.constants.NIELL_AW = Array([0.00058022, 0.00058022, 0.00056795, 0.00058118, 0.00059728, 0.00061642, 0.00061642], dtype=float64)#
Wet mapping coefficient a (Niell 1996, Table 2)
- jaxpint.constants.NIELL_BW = Array([0.00142753, 0.00142753, 0.00151386, 0.00145728, 0.00150074, 0.00175991, 0.00175991], dtype=float64)#
Wet mapping coefficient b (Niell 1996, Table 2)
- jaxpint.constants.NIELL_CW = Array([0.04347296, 0.04347296, 0.04672951, 0.04390893, 0.04462698, 0.05473604, 0.05473604], dtype=float64)#
Wet mapping coefficient c (Niell 1996, Table 2)
- jaxpint.constants.NIELL_DOY_OFFSET: int = -28#
Day-of-year offset for seasonal variation (Niell 1996, Eq 2)
- jaxpint.constants.KEPLER_N_ITER: int = 5#
Halley’s method iterations for Kepler equation (cubically convergent; 5 iterations reaches machine epsilon even at e=0.95 with Danby initial guess)
- jaxpint.constants.NUMERIC_PARAM_TYPES = frozenset({'AngleParameter', 'MJDParameter', 'floatParameter'})#
PINT parameter types that map to numeric values
- jaxpint.constants.PLANETS = ('jupiter', 'saturn', 'venus', 'uranus', 'neptune', 'earth')#
Planets used for Shapiro delay and position lookups