sky3d: Spherical Polar Matching
matcher=sky3d values*='<ra/degrees> <dec/degrees> <distance>'
params='<error/units of distance>'
tuning='<bin-factor>'
values*:
ra/degrees: Right Ascensiondec/degrees: Declinationdistance: Distance from originparams:
error/units of distance: Maximum Cartesian separation for matchtuning:
bin-factor: Scaling factor to adjust bin size; larger values mean larger bins
The sky3d matcher compares positions in the volume of
the sky taking account of distance from the observer.
The position in three-dimensional space is calculated for each
row using the ra, dec and distance
as spherical polar coordinates, where distance is the
distance from the observer along the line of sight.
Rows are considered to match when their positions in this space are
within error units of each other.
The units of error are the same as those of
distance.
As with sky matching,
other longitude/latitude coordinate pairs may be used in place of
right ascension and declination.