Abstract: A hollow surveying retroreflector assembly is provided which is comprised of a hollow retroreflector received within and adhered to a receptacle. The retroreflector has three plates having optically flat reflecting faces disposed at right angles to each other. The receptacle has a conically configured interior for receiving the retroreflector and for maintaining the perpendicular alignment of the reflecting faces of the plates of the retroreflector. The receptacle having the retroreflector inside is then received within an outer casing to allow for mounting of the hollow surveying retroreflector assembly.

Abstract: This invention relates to lateral transfer retroreflectors having a tubular member comprised of a material having dimensions which are relatively stable with respect to temperature. The retroreflector is further comprised of a roof mirror having two reflective surfaces mounted to one end of the tubular member at three coplanar mounting surfaces of the roof mirror. Mounted on the opposite end of the tubular member is a mirror panel having a reflective surface which is perpendicular to both of the reflective surfaces of the roof mirror. The tubular member has openings for light to pass through and thereby reflect off of the roof mirror and the mirror panel. One of the openings increases the effective aperture of the lateral transfer retroreflector.