The following two examples show how to use the ST_SpheroidalDistance method to get the spheroidal distance between Madison (-89.39, 43.09) and Chicago (-87.65, 41.90):
CREATE TABLE sample_points1 (skey1 INTEGER, point1 ST_Geometry);
INSERT INTO sample_points1 VALUES (101, 'POINT(-89.39 43.09)');
SELECT point1.ST_SpheroidalDistance(
new ST_Geometry(
'ST_POINT(-87.65 41.90)'), 6378137, 298.257223563)
FROM sample_points1;
SELECT point1.ST_SpheroidalDistance(
new ST_Geometry('POINT(-87.65 41.90)') )
FROM sample_points1;