empyrean.BPlanes

class BPlanes(table, **kwargs)

Bases: Table

B-plane geometry breakdowns tagged by uncertainty method.

One row per (method × orbit × body) close-approach encounter. Mirrors empyrean_core.impact.BPlaneData (= villeneuve’s upstream type) flattened to columns: $B \cdot R$, $B \cdot T$, miss distance, hyperbolic excess velocity, the projected covariance, and the 3σ uncertainty ellipse (semi-major / semi-minor / rotation angle).

Closest-approach time carried as an Epochs sub-table — same convention as ImpactProbabilities.

Methods

__init__(table, **kwargs)
apply_mask(mask)	Return a new table with rows filtered to match a boolean mask.
as_column([nullable, metadata])	Embed the Table as a column in another Table.
attributes()	Return a dictionary of the table's attributes.
chunk_counts()	Returns the number of discrete memory chunks that make up each of the Table's underlying arrays.
column(column_name)	Returns the column with the given name as a raw pyarrow ChunkedArray.
drop_duplicates([subset, keep])	Drop duplicate rows from a ~quivr.Table.
empty(**kwargs)	Create an empty instance of the table.
flattened_table()	Completely flatten the Table's underlying Arrow table, taking into account any nested structure, and return the data table itself.
fragmented()	Returns true if the Table has any fragmented arrays.
from_csv(input_file[, validate])	Read a table from a CSV file.
from_dataframe(df[, validate])	Load a DataFrame into the Table.
from_feather(path[, validate])	Read a table from a Feather file.
from_flat_dataframe(df[, validate])	Load a flattened DataFrame into the Table.
from_kwargs([validate, permit_nulls])	Create a Table instance from keyword arguments.
from_parquet(path[, memory_map, ...])	Read a table from a Parquet file.
from_pyarrow(table[, validate, permit_nulls])	Create a new table from a pyarrow Table.
invalid_mask()	Return a boolean mask indicating which rows are invalid.
is_valid()	Validate the table against the schema.
null_mask()	Return a boolean mask indicating which rows of the entire table are null.
nulls(size, **kwargs)	Create a table with nulls.
select(column_name, value)	Select from the table by exact match, returning a new Table which only contains rows for which the value in column_name equals value.
separate_invalid()	Separates rows that have invalid data from those that have valid data.
set_column(name, data)	Return a copy of the table with a particular column replaced with new data.
sort_by(by)	Sorts the Table by the given column name (or multiple columns).
take(row_indices)	Return a new Table with only the rows at the given indices.
to_csv(path[, attribute_columns])	Write the table to a CSV file.
to_dataframe([flatten, attr_handling])	Returns self as a pandas DataFrame.
to_feather(path, **kwargs)	Write the table to a Feather file.
to_parquet(path, **kwargs)	Write the table to a Parquet file.
to_structarray()	Returns self as a StructArray.
unique_indices([subset, keep])	Get the indices of the first or last occurrence of each unique row in the table.
validate()	Validate the table against the schema, raising an exception if invalid.
where(expr)	Return a new table with rows filtered to match an expression.
with_table(table)

Attributes

b_dot_r_km	Öpik $B \cdot R$ coordinate in km.
b_dot_t_km	Öpik $B \cdot T$ coordinate in km.
b_mag_km	Magnitude $|B| = \sqrt{(B \cdot T)^2 + (B \cdot R)^2}$ in km.
body	Body name; B-plane is defined relative to this body's hyperbolic-excess-velocity asymptote at closest approach.
body_radius_km	Body radius (km), pre-inflation.
cov_rr_km2	B-plane projected covariance, R-R component (km²).
cov_tr_km2	B-plane projected covariance, T-R off-diagonal (km²).
cov_tt_km2	B-plane projected covariance, T-T component (km²).
effective_radius_km	Gravitational-focusing-inflated radius $R_\mathrm{eff}^2 = R^2 (1 + (v_\mathrm{esc} / v_\infty)^2)$ in km — the radius $|B|$ is compared against.
ellipse_angle_rad	Rotation angle of the uncertainty ellipse from the +T axis (radians).
epochs	Closest-approach epoch (TDB).
ip_linear	Linear impact probability evaluated against the projected B-plane covariance — convenience copy of the IP that matches this B-plane row.
method	Uncertainty method tag — see ImpactProbabilities.
schema
semi_major_3sig_km	Semi-major axis of the 3σ uncertainty ellipse on the B-plane (km), eigenvector of the projected covariance.
semi_minor_3sig_km	Semi-minor axis of the 3σ uncertainty ellipse on the B-plane (km).
v_inf_km_s	Hyperbolic excess velocity $v_\infty$ at the close approach (km/s).
table

Parameters:

• table (Table)

• kwargs (AttributeValueType)

method

Uncertainty method tag — see ImpactProbabilities.

body

Body name; B-plane is defined relative to this body’s hyperbolic-excess-velocity asymptote at closest approach.

epochs

Closest-approach epoch (TDB).

b_dot_t_km

Öpik $B \cdot T$ coordinate in km. T points along the projection of the planet’s heliocentric velocity onto the B-plane; controls the along-track encounter geometry and the resonant-return / keyhole structure.

schema: ClassVar[Schema] = method: large_string not null body: large_string not null epochs: struct<mjd: double>   child 0, mjd: double b_dot_t_km: double not null b_dot_r_km: double not null b_mag_km: double not null v_inf_km_s: double not null effective_radius_km: double not null body_radius_km: double not null cov_tt_km2: double cov_tr_km2: double cov_rr_km2: double semi_major_3sig_km: double semi_minor_3sig_km: double ellipse_angle_rad: double ip_linear: double

b_dot_r_km

Öpik $B \cdot R$ coordinate in km. R completes a right-handed frame with the inbound asymptote; controls the cross-track miss component.

b_mag_km

Magnitude $|B| = \sqrt{(B \cdot T)^2 + (B \cdot R)^2}$ in km. Impact requires $|B| < R_\mathrm{eff}$.

v_inf_km_s

Hyperbolic excess velocity $v_\infty$ at the close approach (km/s).

effective_radius_km

Gravitational-focusing-inflated radius $R_\mathrm{eff}^2 = R^2 (1 + (v_\mathrm{esc} / v_\infty)^2)$ in km — the radius $|B|$ is compared against.

body_radius_km

Body radius (km), pre-inflation.

cov_tt_km2

B-plane projected covariance, T-T component (km²).

cov_tr_km2

B-plane projected covariance, T-R off-diagonal (km²).

cov_rr_km2

B-plane projected covariance, R-R component (km²).

semi_major_3sig_km

Semi-major axis of the 3σ uncertainty ellipse on the B-plane (km), eigenvector of the projected covariance.

semi_minor_3sig_km

Semi-minor axis of the 3σ uncertainty ellipse on the B-plane (km).

ellipse_angle_rad

Rotation angle of the uncertainty ellipse from the +T axis (radians).

ip_linear

Linear impact probability evaluated against the projected B-plane covariance — convenience copy of the IP that matches this B-plane row.