Unit Descriptions
1 Arcsecond:1 Arcsecond is equal to exactly one thirtysix-hundredth arc degrees (1°/3600). In terms of radians (SI unit) this is π/648000 rad or approximately 4.848 137 x 10-6 rad.
1 Radian:1 Radian is defined as the angle subtended at the center of a circle by an arc whose length is equal to the circle's radius. One full turn is 2π radians.