Surveying pole and secondary sensor unit having toroidal form

A surveying pole for staking out or measuring terrain points, wherein the surveying pole comprises:

• a reflector and/or a GNSS receiver, and
• a secondary sensor unit,
• are attachable to the surveying pole, and wherein the surveying pole comprises a pole tip, and
• two segments, wherein a second segment of the two segments is closer to the pole tip than a first segment of the two segments,
• wherein the secondary sensor unit is attachable to the second segment and the reflector and/or GNSS receiver is attachable to the first segment,
• wherein the surveying pole comprises at a segment end of the second segment a shoulder and a first part of a locking mechanism configured to interact with a second part of the locking mechanism provided by the secondary sensor unit, the first and second part of the locking mechanism configured to provide locking of the secondary sensor unit to the surveying pole,
• in an attached state, the secondary sensor unit is attached to the surveying pole, and the surveying pole passes through a central hole of the secondary sensor unit, which central hole fully pierces the secondary sensor unit, and at least a part of the second segment is fully surrounded by the secondary sensor unit and the first segment is outside the central hole, and
• the surveying pole is configured in such a way that the reflector and/or the GNSS receiver and the secondary sensor unit are independently attachable to the surveying pole, and in the attached state, a distance between an attached reflector and/or GNSS receiver and the secondary sensor unit is known and fixed, and a distance between the pole tip and the attached reflector and/or GNSS receiver is known and independent of whether or not the secondary sensor unit is attached to the surveying pole.