This disclosure describes techniques for sensing an angular position of a rotating object over an angular position range that includes up to 360 degrees using an arc position encoder comprising a substantially 180-degree angular position sensing range. The encoder may include a base comprising an arc length defined by a first and a second end, one or more magnetic field sensors disposed within the base between the first and second ends, and one or more polarity transition sensors also disposed within the base between the first and second ends. The encoder may further include a magnetic target that includes first and second magnetic poles disposed on opposite ends so as to generate a uniform magnetic field, wherein the magnetic target is coupled to the rotating object so as to rotate about an axis of rotation located substantially in a center of a circle defined by the base.