Merge pull request #53 from B612-Asteroid-Institute/jm/aberrated-ephe…

…meris

Add the aberrated orbit to the Ephemeris table

adam_core/orbits/ephemeris.py

@@ -1,71 +1,19 @@
-import pandas as pd
 from quivr import StringColumn, Table
-from typing_extensions import Self
 
+from ..coordinates.cartesian import CartesianCoordinates
 from ..coordinates.spherical import SphericalCoordinates
 
 
 class Ephemeris(Table):
 
     orbit_id = StringColumn(nullable=False)
     object_id = StringColumn()
-    coordinates = SphericalCoordinates.as_column(nullable=False)
-
-    def to_dataframe(self) -> pd.DataFrame:
-        """
-        Convert the Ephemeris table to a pandas DataFrame.
-
-        Returns
-        -------
-        df : `~pandas.DataFrame`
-            The Ephemeris table as a DataFrame.
-        """
-        df = pd.DataFrame()
-        df["orbit_id"] = self.orbit_id
-        df["object_id"] = self.object_id
-        df_coordinates = self.coordinates.to_dataframe()
-
-        df = pd.concat([df, df_coordinates], axis=1)
-        df.rename(
-            columns={
-                "lon": "ra",
-                "lat": "dec",
-                "vlon": "vra",
-                "vlat": "vdec",
-            },
-            inplace=True,
-        )
-        return df
-
-    @classmethod
-    def from_dataframe(cls, df: pd.DataFrame) -> Self:
-        """
-        Instantiate an Ephemeris table from a pandas DataFrame.
-
-        Parameters
-        ----------
-        df : `~pandas.DataFrame`
-            The Ephemeris table as a DataFrame.
-
-        Returns
-        -------
-        ephemeris : `~adam_core.orbits.ephemeris.Ephemeris`
-            The Ephemeris table.
-        """
-        coordinates = SphericalCoordinates.from_dataframe(
-            df.rename(
-                columns={
-                    "ra": "lon",
-                    "dec": "lat",
-                    "vra": "vlon",
-                    "vdec": "vlat",
-                    "obs_code": "origin.code",
-                },
-            ),
-            "equatorial",
-        )
-        return cls.from_kwargs(
-            orbit_id=df["orbit_id"],
-            object_id=df["object_id"],
-            coordinates=coordinates,
-        )
+    coordinates = SphericalCoordinates.as_column()
+
+    # The coordinates as observed by the observer will be the result of
+    # light emitted or reflected from the object at the time of the observation.
+    # Light, however, has a finite speed and so the object's observed cooordinates
+    # will be different from its actual geometric coordinates at the time of observation.
+    # Aberrated coordinates are coordinates that account for the light travel time
+    # from the time of emission/reflection to the time of observation
+    aberrated_coordinates = CartesianCoordinates.as_column(nullable=True)

adam_core/propagator/pyoorb.py

@@ -466,6 +466,23 @@ def _generate_ephemeris(
                     origin=Origin.from_kwargs(code=codes),
                     frame="equatorial",
                 ),
+                aberrated_coordinates=CartesianCoordinates.from_kwargs(
+                    x=ephemeris[:, 24],
+                    y=ephemeris[:, 25],
+                    z=ephemeris[:, 26],
+                    vx=ephemeris[:, 27],
+                    vy=ephemeris[:, 28],
+                    vz=ephemeris[:, 29],
+                    time=Times.from_astropy(
+                        Time(
+                            ephemeris[:, 0],
+                            scale="utc",
+                            format="mjd",
+                        )
+                    ),
+                    origin=Origin.from_kwargs(code=["SUN" for i in range(len(codes))]),
+                    frame="ecliptic",
+                ),
             )
             ephemeris_list.append(ephemeris)