Data Container Field Name Reference

The following table lists field names that are recognized by sbpy when accessing DataClass objects, i.e., Ephem, Orbit, or Phys objects. Each row of the following table represents one property; for each property it lists its description, acceptable field names, provenance (which DataClass class should be used to store this object so that sbpy uses it properly), and its physical dimension (if any).

How do I use this Table?

As an example, imagine you are interested in storing an object’s right ascension into a DataClass object. The field names table tells you that you should name the field either ra or RA, that you should use either a Ephem or Obs object to store the data in, and that the field data should be expressed as angles. Based on this information, we can create a Obs object (presuming that the data were derived from observations):

>>> from sbpy.data import Obs
>>> import astropy.units as u
>>> obs = Obs.from_dict({'ra': [12.345, 12.346, 12.347]*u.deg})
>>> obs['ra']  
<Quantity [12.345, 12.346, 12.347] deg>

Since RA requires an angle as dimension, we use degrees, but we might as well use radians - sbpy will convert the units where necessary. RA has an alternative field name ('RA'), we can now use that name, too, in order to retrieve the data:

>>> obs['RA']  
<Quantity [12.345, 12.346, 12.347] deg>

The field name list is always up to date, but it might not be complete. If you think an important alternative name is missing, please suggest it by opening an issue. However, keep in mind that each alternative field name has to be unique and unambiguous. The source list is located as sbpy.data.Conf.fieldnames in sbpy/data/__init__.py.

Special Case: Epoch

Please note that epochs generally have to be provided as Time objects. The advantage of using such objects is that they can be readily transformed into a wide range of formats (e.g., ISO, Julian Date, etc.) and time scales (e.g., UTC, TT, TDB, etc.) Hence, sbpy requires that all fields referring to a point in time be provided as Time objects.

Field Name List

Description	Field Names	Provenance	Dimension
Target Identifier	targetname, id, Object	Orbit, Ephem, Obs, Phys	None
Target Designation	desig, designation	Orbit, Ephem, Obs, Phys	None
Target Number	number	Orbit, Ephem, Obs, Phys	None
Target Name	name	Orbit, Ephem, Obs, Phys	None
Epoch	epoch, datetime, Date, date, Time, time	Orbit, Ephem, Obs	Time
Semi-Major Axis	a, sma	Orbit	length
Eccentricity	e, ecc	Orbit	None
Inclination	i, inc, incl	Orbit	angle
Perihelion Distance	q, periheldist	Orbit	length
Aphelion Distance	Q, apheldist	Orbit	length
Longitude of the Ascending Node	Omega, longnode, node	Orbit	angle
Argument of the Periapsis	w, argper	Orbit	angle
Mean Anomaly	M, mean_anom	Orbit	angle
True Anomaly	v, true_anom, true_anomaly	Orbit, Ephem, Obs	angle
Arc Length	arc, arc_length	Orbit	angle
Delta-v	delta_v, delta-v	Orbit, Phys	velocity
Minimum Orbit Intersection Distance wrt Mercury	moid_mercury	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Earth	moid_earth	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Venus	moid_venus	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Mars	moid_mars	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Jupiter	moid_jupiter	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Saturn	moid_saturn	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Uranus	moid_uranus	Orbit, Phys	length
Minimum Orbit Intersection Distance wrt Neptune	moid_neptune	Orbit, Phys	length
Tisserand Parameter wrt Jupiter	Tj, tj	Orbit, Phys	None
MPC Orbit Type	mpc_orb_type	Orbit, Phys	None
Epoch of Perihelion Passage	Tp	Orbit	Time
Orbital Period	P, period	Orbit, Phys	time
Heliocentric Distance	r, rh, r_hel, heldist	Ephem, Obs	length
Heliocentric Radial Velocity	r_rate, rh_rate, rdot, r-dot, rhdot, rh-dot	Ephem, Obs	velocity
Distance to the Observer	delta, Delta, obsdist	Ephem, Obs	length
Observer-Target Radial Velocity	delta_rate, deltadot, delta-dot, deldot, del-dot	Ephem, Obs	velocity
Right Ascension	ra, RA	Ephem, Obs	angle
Declination	dec, DEC, Dec	Ephem, Obs	angle
Right Ascension Rate	ra_rate, RA_rate, ra_rates, RA_rates, dRA, dra	Ephem, Obs	angular velocity
RA*cos(Dec) Rate	RA*cos(Dec)_rate, dra cos(dec), dRA cos(Dec), dra*cos(dec), dRA*cos(Dec)	Ephem, Obs	angular velocity
Declination Rate	dec_rate, DEC_rate, Dec_rate, dec_rates, DEC_rates, Dec_rates, dDec, dDEC, ddec	Ephem, Obs	angular velocity
Proper Motion	mu, Proper motion	Ephem, Obs	angular velocity
Proper Motion Direction	Direction, direction	Ephem, Obs	angle
Solar Phase Angle	alpha, phaseangle, Phase, phase	Ephem, Obs	angle
Solar Elongation Angle	elong, solarelong, solarelongation, elongation, Elongation	Ephem, Obs	angle
V-band Magnitude	V, Vmag	Ephem, Obs	magnitude
Heliocentric Ecliptic Longitude	hlon, EclLon, ecllon, HelEclLon, helecllon	Ephem, Obs	angle
Heliocentric Ecliptic Latitude	hlat, EclLat, ecllat, HelEclLat, helecllat	Ephem, Obs	angle
Horizontal Elevation	el, EL, elevation, alt, altitude, Altitude	Ephem, Obs	angle
Horizontal Azimuth	az, AZ, azimuth	Ephem, Obs	angle
Lunar Elongation	lunar_elong, elong_moon, elongation_moon, lunar_elongation, lunarelong	Ephem, Obs	angle
X State Vector Component	x, X, x_vec	Orbit, Ephem, Obs	length
Y State Vector Component	y, Y, y_vec	Orbit, Ephem, Obs	length
Z State Vector Component	z, Z, z_vec	Orbit, Ephem, Obs	length
X Velocity Vector Component	vx, dx, dx/dt	Orbit, Ephem, Obs	velocity
Y Velocity Vector Component	vy, dy, dy/dt	Orbit, Ephem, Obs	velocity
Z Velocity Vector Component	vz, dz, dz/dt	Orbit, Ephem, Obs	velocity
X heliocentric position vector	x_h, X_h	Orbit, Ephem, Obs	length
Y heliocentric position vector	y_h, Y_h	Orbit, Ephem, Obs	length
Z heliocentric position vector	z_h, Z_h	Orbit, Ephem, Obs	length
Comet Total Absolute Magnitude	m1, M1	Ephem, Obs	magnitude
Comet Nuclear Absolute Magnitude	m2, M2	Ephem, Obs	magnitude
Total Magnitude Scaling Factor	k1, K1	Ephem, Obs	None
Nuclear Magnitude Scaling Factor	k2, K2	Ephem, Obs	None
Phase Coefficient	phase_coeff, Phase_coeff	Ephem, Obs	None
Information on Solar Presence	solar_presence, Solar_presence	Ephem, Obs	None
Information on Moon and target status	status_flag, Status_flag	Ephem, Obs	None
Apparent Right Ascension	RA_app, ra_app	Ephem, Obs	angle
Apparent Declination	DEC_app, dec_app	Ephem, Obs	angle
Azimuth Rate (dAZ*cosE)	az_rate, AZ_rate	Ephem, Obs	angular velocity
Elevation Rate (d(ELV)/dt)	el_rate, EL_rate	Ephem, Obs	angular velocity
Satellite Position Angle	sat_pang, Sat_pang	Ephem, Obs	angle
Local Sidereal Time	siderealtime, Siderealtime	Ephem, Obs	time
Target Optical Airmass	airmass, Airmass	Ephem, Obs	None
V Magnitude Extinction	vmagex, Vmagex	Ephem, Obs	magnitude
Surface Brightness	Surfbright, surfbright	Ephem, Obs	magnitude/angle^2
Fraction of Illumination	frac_illum, Frac_illum	Ephem, Obs	percent
Illumination Defect	defect_illum, Defect_illum	Ephem, Obs	angle
Target-primary angular separation	targ_sep, Targ_sep	Ephem, Obs	angle
Target-primary visibility	targ_vis, Targ_vis	Ephem, Obs	None
Angular width of target	targ_width, Targ_width	Ephem, Obs	angle
Apparent planetodetic longitude	pldetic_long, Pldetic_long	Ephem, Obs	angle
Apparent planetodetic latitude	pldetic_lat, Pldetic_lat	Ephem, Obs	angle
Apparent planetodetic Solar longitude	pltdeticSol_long, PltdeticSol_long	Ephem, Obs	angle
Apparent planetodetic Solar latitude	pltdeticSol_lat, PltdeticSol_lat	Ephem, Obs	angle
Target sub-solar point position angle	subsol_ang, Subsol_ang	Ephem, Obs	angle
Target sub-solar point angle distance	subsol_dist, Subsol_dist	Ephem, Obs	angle
Target North pole position angle	npole_angle, Npole_angle	Ephem, Obs	angle
Target North pole position distance	npole_dist, Npole_dist	Ephem, Obs	angle
Observation centric ecliptic longitude	obs_ecl_long, Obs_ecl_long	Ephem, Obs	angle
Observation centric ecliptic latitude	obs_ecl_lat, Obs_ecl_lat	Ephem, Obs	angle
One-way light time	lighttime, Lighttime	Ephem, Obs	time
Target center velocity wrt Sun	vel_sun, Vel_sun	Ephem, Obs	velocity
Target center velocity wrt Observer	vel_obs, Vel_obs	Ephem, Obs	velocity
Lunar illumination	lun_illum, Lun_illum	Ephem, Obs	percent
Apparent interfering body elongation wrt observer	ib_elong, IB_elong	Ephem, Obs	angle
Interfering body illumination	ib_illum, IB_illum	Ephem, Obs	percent
Observer primary target angle	targ_angle_obs, Targ_angle_obs	Ephem, Obs	angle
Orbital plane angle	orbangle_plane, Orbangle_plane	Ephem, Obs	deg
Constellation ID containing target	constellation, Constellation	Ephem, Obs	None
Target North Pole RA	targ_npole_ra, targ_npole_RA	Ephem, Obs	angle
Target North Pole DEC	targ_npole_dec, targ_npole_DEC	Ephem, Obs	angle
Galactic Longitude	glx_long, Glx_long	Ephem, Obs	angle
Galactic Latitude	glx_lat, Glx_lat	Ephem, Obs	angle
Local apparent solar time	solartime	Ephem, Obs	None
Observer light time from Earth	earthlighttime, Earthlighttime	Ephem, Obs	time
3 sigma positional uncertainty RA	RA_3sigma, ra_3sigma	Ephem, Obs	angle
3 sigma positional uncertainty DEC	DEC_3sigma, dec_3sigma	Ephem, Obs	angle
3 sigma positional uncertainty semi-major axis	sma_3sigma	Ephem, Obs	angle
3 sigma positional uncertainty semi-minor axis	smi_3sigma	Ephem, Obs	angle
3 sigma positional uncertainty position angle	posangle_3sigma	Ephem, Obs	angle
3 sigma positional uncertainty ellipse area	area_3sigma	Ephem, Obs	angular area
3 sigma positional uncertainty root sum square	rss_3sigma	Ephem, Obs	angle
3 sigma range uncertainty	r_3sigma	Ephem, Obs	length
3 sigma range rate uncertainty	r_rate_3sigma	Ephem, Obs	velocity
3 sigma doppler radar uncertainty at S-band	sband_3sigma	Ephem, Obs	frequency
3 sigma doppler radar uncertainty at X-band	xband_3sigma	Ephem, Obs	frequency
3 sigma doppler round-trip delay uncertainty	dopdelay_3sigma	Ephem, Obs	time
Local apparent hour angle	locapp_hourangle	Ephem, Obs	time
True phase angle	true_phaseangle	Ephem, Obs	angle
Phase angle bisector longitude	pab_long	Ephem, Obs	angle
Phase angle bisector latitude	pab_lat	Ephem, Obs	angle
Absolute V-band Magnitude	abs_V, abs_Vmag	Ephem, Obs	magnitude
Satellite X-position	sat_X, sat_x	Ephem, Obs	angle
Satellite Y-position	sat_y, sat_Y	Ephem, Obs	angle
Atmospheric Refraction	atm_refraction, refraction	Ephem, Obs	angle
Infrared Beaming Parameter	eta, Eta	Ephem, Obs	None
Temperature	temp, Temp, temperature, Temperature	Phys, Ephem, Obs	temperature
Effective Diameter	d, D, diam, diameter, Diameter	Phys	length
Effective Radius	R, radius	Phys	length
Geometric Albedo	pv, pV, p_v, p_V, geomalb	Phys	None
Bond Albedo	A, bondalbedo	Phys	None
Emissivity	emissivity, Emissivity	Phys	None
Absolute Magnitude	absmag, H	Phys, Ephem, Orbit	magnitude
Photometric Phase Slope Parameter	G, slope	Phys, Ephem, Orbit	None
Molecule Identifier	mol_tag, mol_name	Phys	None
Transition frequency	t_freq	Phys	frequency
Integrated line intensity at 300 K	lgint300	Phys	intensity
Integrated line intensity at designated Temperature	intl, lgint	Phys	intensity
Partition function at 300 K	partfn300	Phys	None
Partition function at designated temperature	partfn	Phys	None
Upper state degeneracy	dgup	Phys	None
Upper level energy in Joules	eup_j, eup_J	Phys	energy
Lower level energy in Joules	elo_j, elo_J	Phys	energy
Degrees of freedom	degfr, ndf, degfreedom	Phys	None
Einstein Coefficient	au, eincoeff	Phys	1/time
Timescale * r^2	beta, beta_factor	Phys	time * length^2
Total Number	totnum, total_number_nocd	Phys	None
Column Density from Bockelee Morvan et al. 2004	cdensity, col_density	Phys	1/length^2