Louisiana Administrative Code › Title 43 - NATURAL RESOURCES › Part XXVII - State Lands › Subpart 1 - Land Information Mapping and Map Records System › Chapter 5 - Ground Control › Section XXVII-511 - Horizontal Control

Current through Register Vol. 50, No. 6, June 20, 2024
A. All
				  horizontal control surveys shall be established by conventional triangulation,
				  traverse, or Global Positioning System (GPS) techniques, including any
				  combination thereof, as dictated by specific project requirements.
B. Triangulation and traverse surveys shall
				  be performed in accordance with applicable requirements set forth within the
Standards and Specifications for Geodetic Control Networks
, as
				  prepared by the Federal Geodetic Control Committee (FGCC), dated September,
				  1984, inclusive of any and all subsequent revisions in effect at the time such
				  surveys are conducted.
C. GPS
				  surveys shall be performed in accordance with applicable requirements set forth
				  within FGCC publication
Geometric Geodetic Accuracy Standards and
				  Specifications for Using GPS Relative Positioning Techniques
, Version
				  5.0, revised August 1989, inclusive of any and all subsequent revisions in
				  effect at the time such surveys are conducted.
D. All horizontal control established shall
				  conform to the minimum requirements for Second Order Class II surveys as set
				  forth within the FGCC Standards and Specifications, and shall result in a
				  minimum distance closure accuracy of 1:20,000. Any surveys originated from
				  sparse or distant existing horizontal control monumentation shall be performed
				  to a higher order of accuracy as may be required to ensure compliance with
				  these standards.
E. Horizontal
				  control surveys performed for the purpose of establishing new permanent
				  horizontal control monuments will be submitted to NGS for verification and
				  publication as part of the National Horizontal Reference Network. Strict
				  compliance to FGCC Blue Book Specifications must be adhered to and all data
				  shall be submitted in accordance with NOAA Manual NOS NGS 2,
Input
				  Formats and Specifications of the National Geodetic Survey Database; Volume
				  1
-
Horizontal Control Data
.
F. All additional temporary photo control
				  points required for photogrammetric control and analytic aerial triangulation
				  shall be established and pretargeted prior to photography. All temporary
				  control points established shall be clearly documented by appropriate
				  descriptions referenced to landmarks and identified by field survey ties to
				  three or more discrete photo image points in the immediate vicinity. In the
				  absence of discrete reference points in the immediate vicinity, collateral ties
				  shall be made to recoverable markers or stakes set and established adjacent
				  thereto.
G. Both conventional and
				  GPS surveys shall start and end on existing NGS control. All field traverses
				  will be a closed loop or otherwise shall close on an adjacent existing NGS
				  horizontal control station. If a new station or temporary photo control point
				  is established in the vicinity of an existing horizontal control monument,
				  direct observations between the two positions must be made whenever the
				  distance between them is less than 20 percent of the shortest distance as
				  measured over the proposed and/or established survey lines (20 percent
				  rule).
H. The spatial distribution,
				  quantity and configuration of all pretargeted horizontal ground control
				  positions established shall be sufficient to facilitate analytic aerial
				  triangulation and subsequent digital map compilation in conformance with these
				  standards. Regardless of terrain configuration, the minimum spatial
				  distribution of pretargeted horizontal ground control positions to be
				  established within and adjacent to any project area shall be such that
				  photo-identifiable ground control points will be established along every other
				  flight line at intervals not to exceed five contiguous photogrammetric stereo
				  models regardless of scale.
AUTHORITY NOTE:
					 Promulgated in accordance with
					 R.S.
					 50:171.