Legislative Issues for the New Datums of 2022 NGS Geospatial Summit Arlington, VA April, 2015 Dave Doyle NGS, Chief Geodetic Surveyor (Retired)

FEDERAL Federal Geodetic Control Committee (FGCS) drafts and publishes a notice in the Federal Registry – NGS has the chair of FGCS STATE Legislation published as part of state legal code Support may vary from state-to-state typically Land Surveyors Professional Society in collaboration with DoT. Now this may include state GIS organization(s ) Federal and State Regulations

NAD 83 – June 14, 1989 NAVD 88 – June 24, 1993 ASVD 02 – Jan 22, 2009 GUVD 04 – Jan 22, 2009 NMVD 03 – Jan, 22, 2009 VIVD 09 – Dec 12, 2011 PRVD 02 – July 23, 2012 GEODETIC DATUMS FEDERAL REGISTER NOTICES

Developed from a request in 1933 from the North Carolina State Highway and Public Works Commission -- (George F. Syme) Zones designed by U.S. Coast and Geodetic Survey (Oscar S. Adams) Two basic map projections used: Lambert Conformal Conic – States or parts of states that have a more east-west orientation Transverse Mercator – States or parts of states that have a more north-south orientation Zone boundaries along International, state and county boundaries Zones typically 158 miles wide – this limits the maximum geodetic to grid distance distortion to 1:10,000 All coordinate values in U.S. Survey Feet Conversions to/from latitude & longitude calculated using tables STATE PLANE COORDINATE SYSTEM NAD 27

Geometric parameters of original SPC zones left unchanged unless requested by “the State” Most states changed no zone parameters California dropped zone 7 Maryland moved the latitude of the origin south 10’ Montana moved from 4 zones to a single zone New Jersey moved the Central Meridian 10’ east (aligned with NY E) South Carolina moved from 2 zones to a single zone All states got new false northing and easting values defined in meters. NGS publishes all values in meters, conversions to feet defined by individual state legislation or notice in the Federal Register: 1 m = U.S. Survey Feet 1 m = International Feet STATE PLANE COORDINATE SYSTEM NAD 83

Codes of Virginia and Tennessee VA -- Title 55, Property and Conveyances, Chapter 17, to TN – Title 66, Property, Chapter 6, 101 to 106 The systems of plane coordinates which have been established by the National Ocean Survey/National Geodetic Survey or its successors for defining and stating the positions or locations of points on the surface of the earth within the Commonwealth of Virginia are hereafter to be known and designated as the "Virginia Coordinate System of 1927" and the "Virginia Coordinate System of 1983." The position of the Virginia Coordinate systems shall be as marked on the ground by triangulation or traverse stations established in conformity with the standards of accuracy and specifications for first-order and second-order geodetic surveying as prepared and published by the Federal Geodetic Control Committee (FGCC) of the United States Department of Commerce. No coordinates based on either Tennessee coordinate system, purporting to define the position of a point on a land boundary, shall be presented to be recorded in any public land records or deed records unless such point is within five kilometers (5 km) of a horizontal control monument STATE LEGISLATION

Horizontal/Geometric and Vertical/Geopotential datums should be defined in the same FRN/State Legislation Remove references to old proportional part orders of accuracy Remove references to triangulation/traverse control points Remove references to limits on distance to control points NSPS Collaborate with NGS to develop model legislation RECOMENDATIONS

Should include requirements for metadata DATUM and REALIZATION Include datum designation, iteration and epoch e.g. NAD 83 (2011) Epoch NAVD 88 Epoch UNITS Meters U.S. Survey Feet International Feet ACCURACY.01 m,.05 ft, 4 ft FRNs and State Legislation

GOOD COORDINATION BEGINS WITH GOOD COORDINATES GEOGRAPHY WITHOUT GEODESY IS A FELONY