LAC 43:XXVII.513. Vertical Control

A. All required vertical control shall be extended from existing NGS or U.S. Geological Survey Benchmarks which are published by NGS as part of the National Geodetic Vertical Reference System. B. All vertical control established shall conform to the minimum requirements for third order surveys as set forth within the FGCC Standards and Specifications, and shall result in a minimum vertical closure accuracy of 0.05 feet times the square root (in miles) of individual level lines run. C. Existing vertical control monuments and photogrammetric control points necessary for the establishment of contour lines, spot elevations or related vertical information may be either pretargeted prior to photography or field located following completion of photography depending on project requirements. Nontargeted control points will be pinpricked in the field on the appropriate aerial photograph following completion of aerial photography. The location of each pinpricked control point shall be referenced and precisely described on the back of each photograph.