Missouri Code of State Regulations › Title 10 - DEPARTMENT OF NATURAL RESOURCES › Division 30 - Land Survey › Chapter 4 - First and Second Order Horizontal and Vertical Control › Section 10 CSR 30-4.050 - GPS Survey Guidelines

Current through Register Vol. 49, No. 14, July 15, 2024
PURPOSE: This rule prescribes the minimum procedures
				  for first or second order Global Positioning System surveys.
(1) Direct connections must be made to any
				adjacent observable National Geographic Reference System (NGRS) and/or Missouri
				Geographic Reference System (MO GRS) station located five kilometers (5 km) or
				less from any new station.
(2) At
				least three (3) existing higher or equal order control points must be included
				in any proposed Global Positioning System (GPS) survey. Whenever possible these
				should be three (3) 3-d control points. Otherwise two
(2) sets of three (3) points (three (3) 2-d
				horizontal points and three (3) vertical control points) must be used. These
				control points should be chosen to be roughly equidistant on the periphery of
				the network so that they enclose as much of the proposed network as
				possible.
(3) Each new point to be
				established by the proposed GPS survey must be occupied at least two (2)
				separate times to enable proper checking of blunders (for example, incorrect
				point, setup errors, incorrect antenna heights). A separate occupation is one
				where the antenna has been taken down and set up again and the receiver
				restarted.
(4) Each point must be
				connected by simultaneous occupations (that is, base line) to at least three
				(3) other points in the network after outlier base lines have been rejected
				from the adjustment. Because it is generally easier to resolve the integer
				phase ambiguities over shorter base line, adjacent points should be connected
				wherever possible.
(5) At least two
				(2) receivers must be used for relative positioning, although three (3) or more
				may be used for more efficient operation and increased station reoccupation and
				base line repeatability.
(6) A
				preanalysis should be performed to determine the minimum occupation time
				required to achieve the required standard of accuracy. In addition, the most
				appropriate satellites to observe at each site should also be selected for
				receivers unable to track all of the "visible" satellites. The preanalysis
				should be specific for carrier phase relative positioning.
(7) In order to meet second order accuracies,
				the carrier beat phase must be observed together with a time tag for each
				observation. Pseudo-range observations are not precise enough for control
				surveys and cannot be used.
(8) A
				detailed field log must be kept during observation taken at each station. At
				the very least the following information must be recorded:
(A) Universal Time Correction (UTC) date of
				observations;
(B) Station
				identification (name and number);
(C) Session identification;
(D) Serial numbers of receiver, antenna, and
				data logger;
(E) Receiver
				operator;
(F) Antenna height and
				offset from monument, if any to one millimeter (1 mm). Note should be made of
				any deviation from standard method of measuring HI;
(G) Diagram illustrating stamping on the
				monument;
(H) Other stations
				observed during session;
(I)
				Starting and ending time (UTC) of observations;
(J) Satellites observed (including time of
				changes); and
(K) Completed field
				log data forms for each station occupation will be submitted either using those
				provided by the Department of Natural Resources (DNR) or some other type
				containing all necessary information found on the DNR forms.