33-133 - Ground markings of system; accuracy specifications; horizontal control stations
33-133. Ground markings of system; accuracy specifications; horizontal control stations
A. The position of the Arizona coordinate system shall be marked on the ground by horizontal control stations which have been established in conformity with standards adopted by the federal geodetic control committee for first order, second order class I or second order class II surveys or equivalent standards adopted by successors, at the time the surveys were made and computed on the North American datum, 1983.
B. A horizontal control station normally consists of, if practicable, a group of bronze or brass discs imbedded in concrete posts nearly flush with the ground surface or cemented into holes drilled into rock outcrops or ledges in such a configuration that the station is referenced by a subsurface mark in a precise vertical register with the surface mark, two reference marks, similar to the surface mark accurately located by azimuth and horizontal distance in respect to the horizontal control station and not more than one hundred fifty feet distant and an azimuth mark which may be similar to the horizontal control station not less than one thousand feet distant, or optionally, an object not less than three thousand feet distant such as a church spire, water tank, radio or television transmitting antenna, by which azimuth mark subsequent surveys may be accurately oriented.
C. Horizontal control stations shall be established, if practicable, in proximity to road intersections, hill or mountain tops and similar locations as an aid in the field searches for the horizontal control stations.