Name
ST_CPAWithin — Returns true if the trajectories' closest points of approach are within the specified distance.
Synopsis
float8 ST_CPAWithin(geometry track1, geometry track2, float8 maxdist);
Description
Checks whether two moving objects have ever been within the specified max distance.
Inputs must be valid trajectories as checked by ST_IsValidTrajectory. False is returned if the trajectories do not overlap on the M range.
Availability: 2.2.0
This function supports 3d and will not drop the z-index.
Examples
WITH inp AS ( SELECT
ST_AddMeasure('LINESTRING Z (0 0 0, 10 0 5)'::geometry,
extract(epoch from '2015-05-26 10:00'::timestamptz),
extract(epoch from '2015-05-26 11:00'::timestamptz)
) a,
ST_AddMeasure('LINESTRING Z (0 2 10, 12 1 2)'::geometry,
extract(epoch from '2015-05-26 10:00'::timestamptz),
extract(epoch from '2015-05-26 11:00'::timestamptz)
) b
)
SELECT ST_CPAWithin(a,b,2), ST_DistanceCPA(a,b) distance FROM inp;
st_cpawithin | distance
--------------+------------------
t | 1.96521473776207