Continuously operating GNSS station or CORS site. Mark is unable to be physically occupied. Horizontal reference point is the centre of 5/8ö thread. The vertical reference is the flat surface at top of monument. There is a 0.002m difference between the GNSS antenna reference point (ARP) and the vertical reference point (antenna height). Top of SS centre block is 710 mm above the top of previous mark (Trig T1- A24A). For more information see http://www.linz.govt.nz/positionz