gcirc¶
- pydl.goddard.astro.gcirc(ra1, dec1, ra2, dec2, units=2)[source]¶
Computes rigorous great circle arc distances.
- Parameters:
- ra1, dec1, ra2, dec2
float
or array-like RA and Dec of two points.
- units{ 0, 1, 2 }, optional
units = 0: everything is already in radians
units = 1: RA in hours, dec in degrees, distance in arcsec.
units = 2: RA, dec in degrees, distance in arcsec (default)
- ra1, dec1, ra2, dec2
- Returns:
float
or array-likeThe angular distance. Units of the value returned depend on the input value of
units
.
Notes
The formula below is the one best suited to handling small angular separations. See: https://en.wikipedia.org/wiki/Great-circle_distance