sbpy Field Names¶
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 |
|
None |
|
Target Designation |
|
None |
|
Target Number |
|
None |
|
Target Name |
|
None |
|
Epoch |
|
||
Semi-Major Axis |
|
length |
|
Eccentricity |
|
None |
|
Inclination |
|
angle |
|
Perihelion Distance |
|
length |
|
Aphelion Distance |
|
length |
|
Longitude of the Ascending Node |
|
angle |
|
Argument of the Periapsis |
|
angle |
|
Mean Anomaly |
|
angle |
|
True Anomaly |
|
angle |
|
Arc Length |
|
angle |
|
Delta-v |
|
velocity |
|
Minimum Orbit Intersection Distance wrt Mercury |
|
length |
|
Minimum Orbit Intersection Distance wrt Earth |
|
length |
|
Minimum Orbit Intersection Distance wrt Venus |
|
length |
|
Minimum Orbit Intersection Distance wrt Mars |
|
length |
|
Minimum Orbit Intersection Distance wrt Jupiter |
|
length |
|
Minimum Orbit Intersection Distance wrt Saturn |
|
length |
|
Minimum Orbit Intersection Distance wrt Uranus |
|
length |
|
Minimum Orbit Intersection Distance wrt Neptune |
|
length |
|
Tisserand Parameter wrt Jupiter |
|
None |
|
MPC Orbit Type |
|
None |
|
Epoch of Perihelion Passage |
|
||
Orbital Period |
|
time |
|
Heliocentric Distance |
|
length |
|
Heliocentric Radial Velocity |
|
velocity |
|
Distance to the Observer |
|
length |
|
Observer-Target Radial Velocity |
|
velocity |
|
Right Ascension |
|
angle |
|
Declination |
|
angle |
|
Right Ascension Rate |
|
angular velocity |
|
RA*cos(Dec) Rate |
|
angular velocity |
|
Declination Rate |
|
angular velocity |
|
Proper Motion |
|
angular velocity |
|
Proper Motion Direction |
|
angle |
|
Solar Phase Angle |
|
angle |
|
Solar Elongation Angle |
|
angle |
|
V-band Magnitude |
|
magnitude |
|
Heliocentric Ecliptic Longitude |
|
angle |
|
Heliocentric Ecliptic Latitude |
|
angle |
|
Horizontal Elevation |
|
angle |
|
Horizontal Azimuth |
|
angle |
|
Lunar Elongation |
|
angle |
|
X State Vector Component |
|
length |
|
Y State Vector Component |
|
length |
|
Z State Vector Component |
|
length |
|
X Velocity Vector Component |
|
velocity |
|
Y Velocity Vector Component |
|
velocity |
|
Z Velocity Vector Component |
|
velocity |
|
X heliocentric position vector |
|
length |
|
Y heliocentric position vector |
|
length |
|
Z heliocentric position vector |
|
length |
|
Comet Total Absolute Magnitude |
|
magnitude |
|
Comet Nuclear Absolute Magnitude |
|
magnitude |
|
Total Magnitude Scaling Factor |
|
None |
|
Nuclear Magnitude Scaling Factor |
|
None |
|
Phase Coefficient |
|
None |
|
Information on Solar Presence |
|
None |
|
Information on Moon and target status |
|
None |
|
Apparent Right Ascension |
|
angle |
|
Apparent Declination |
|
angle |
|
Azimuth Rate (dAZ*cosE) |
|
angular velocity |
|
Elevation Rate (d(ELV)/dt) |
|
angular velocity |
|
Satellite Position Angle |
|
angle |
|
Local Sidereal Time |
|
time |
|
Target Optical Airmass |
|
None |
|
V Magnitude Extinction |
|
magnitude |
|
Surface Brightness |
|
magnitude/angle^2 |
|
Fraction of Illumination |
|
percent |
|
Illumination Defect |
|
angle |
|
Target-primary angular separation |
|
angle |
|
Target-primary visibility |
|
None |
|
Angular width of target |
|
angle |
|
Apparent planetodetic longitude |
|
angle |
|
Apparent planetodetic latitude |
|
angle |
|
Apparent planetodetic Solar longitude |
|
angle |
|
Apparent planetodetic Solar latitude |
|
angle |
|
Target sub-solar point position angle |
|
angle |
|
Target sub-solar point angle distance |
|
angle |
|
Target North pole position angle |
|
angle |
|
Target North pole position distance |
|
angle |
|
Observation centric ecliptic longitude |
|
angle |
|
Observation centric ecliptic latitude |
|
angle |
|
One-way light time |
|
time |
|
Target center velocity wrt Sun |
|
velocity |
|
Target center velocity wrt Observer |
|
velocity |
|
Lunar illumination |
|
percent |
|
Apparent interfering body elongation wrt observer |
|
angle |
|
Interfering body illumination |
|
percent |
|
Observer primary target angle |
|
angle |
|
Orbital plane angle |
|
deg |
|
Constellation ID containing target |
|
None |
|
Target North Pole RA |
|
angle |
|
Target North Pole DEC |
|
angle |
|
Galactic Longitude |
|
angle |
|
Galactic Latitude |
|
angle |
|
Local apparent solar time |
|
None |
|
Observer light time from Earth |
|
time |
|
3 sigma positional uncertainty RA |
|
angle |
|
3 sigma positional uncertainty DEC |
|
angle |
|
3 sigma positional uncertainty semi-major axis |
|
angle |
|
3 sigma positional uncertainty semi-minor axis |
|
angle |
|
3 sigma positional uncertainty position angle |
|
angle |
|
3 sigma positional uncertainty ellipse area |
|
angular area |
|
3 sigma positional uncertainty root sum square |
|
angle |
|
3 sigma range uncertainty |
|
length |
|
3 sigma range rate uncertainty |
|
velocity |
|
3 sigma doppler radar uncertainty at S-band |
|
frequency |
|
3 sigma doppler radar uncertainty at X-band |
|
frequency |
|
3 sigma doppler round-trip delay uncertainty |
|
time |
|
Local apparent hour angle |
|
time |
|
True phase angle |
|
angle |
|
Phase angle bisector longitude |
|
angle |
|
Phase angle bisector latitude |
|
angle |
|
Absolute V-band Magnitude |
|
magnitude |
|
Satellite X-position |
|
angle |
|
Satellite Y-position |
|
angle |
|
Atmospheric Refraction |
|
angle |
|
Infrared Beaming Parameter |
|
None |
|
Temperature |
|
temperature |
|
Effective Diameter |
|
length |
|
Effective Radius |
|
length |
|
Geometric Albedo |
|
None |
|
Bond Albedo |
|
None |
|
Emissivity |
|
None |
|
Absolute Magnitude |
|
magnitude |
|
Photometric Phase Slope Parameter |
|
None |
|
Molecule Identifier |
|
None |
|
Transition frequency |
|
frequency |
|
Integrated line intensity at 300 K |
|
intensity |
|
Integrated line intensity at designated Temperature |
|
intensity |
|
Partition function at 300 K |
|
None |
|
Partition function at designated temperature |
|
None |
|
Upper state degeneracy |
|
None |
|
Upper level energy in Joules |
|
energy |
|
Lower level energy in Joules |
|
energy |
|
Degrees of freedom |
|
None |
|
Einstein Coefficient |
|
1/time |
|
Timescale * r^2 |
|
time * length^2 |
|
Total Number |
|
None |
|
Column Density from Bockelee Morvan et al. 2004 |
|
1/length^2 |