GEODETIC INFRASTRUCTURE Walter Volkmann Manager of Technical Operations L. D. Bradley Land Surveyors Gainesville, Florida

GEODETIC INFRASTRUCTURE Brief History 1.Astronomical Observations (Laplace Fixes) & Base Line Extensions with Classical Triangulation (10ppm) 2.Spirit Levelling 3.Introduction of EDM - control of scale in triangulation networks, geodetic traversing with astro. Obs. to control orientation Cumbersome and slow Ad Hoc extensions of network, often disconnected Difficult to maintain homogeneity across country Horizontal separate from vertical Pre-Satellite Epoch

GEODETIC INFRASTRUCTURE 1.Doppler Surveys - World wide coverage, absolute positioning accurate to 1m. Highly specialized application. 2.GPS - Global, diverse applications with accuracies from 30m to mm (1ppm) 3.GNSS – GPS, Glonass, Galileo? Satellite Epoch

GEODETIC INFRASTRUCTURE Components 1. Physical Monumentation 2. Abstract Parts 3. Enhancing Facilities

GEODETIC INFRASTRUCTURE PHYSICAL MONUMENTATION Visibility conditions Stable and Permanent Protected by Law (Public Property) Accessible Appropriate density

GEODETIC INFRASTRUCTURE NUMERICAL AND VERBAL ATTRIBUTES Visibility conditions 3D Position, XYZ & φλhe on specified datum and ref ellipsoid Accuracy Statement Description (digital photo) Recovery notes Ideally this info should be maintained in an internet accessible database which allows users to contribute to the recovery history

GEODETIC INFRASTRUCTURE AQ2646 *CURRENT SURVEY CONTROL AQ2646 ___________________________________________________________________ AQ2646* NAD 83(2007) (N) (W) ADJUSTED AQ2646* NAVD (meters) 68.0 (feet) GPS OBS AQ2646 ___________________________________________________________________ AQ2646 X - 793, (meters) COMP AQ2646 Y - -5,471, (meters) COMP AQ2646 Z - 3,168, (meters) COMP AQ2646 LAPLACE CORR (seconds) DEFLEC99 AQ2646 ELLIP HEIGHT (meters) (02/10/07) ADJUSTED AQ2646 GEOID HEIGHT (meters) GEOID03 AQ2646 AQ Accuracy Estimates (at 95% Confidence Level in cm) AQ2646 Type PID Designation North East Ellip AQ AQ2646 NETWORK AQ2646 FLGPS AQ AQ2646 AQ2646.The horizontal coordinates were established by GPS observations AQ2646.and adjusted by the National Geodetic Survey in February AQ2646.The orthometric height was determined by GPS observations and a AQ2646.high-resolution geoid model using precise GPS observation and AQ2646.processing techniques. It supersedes the leveled height previously AQ2646.determined for this station. AQ2646.The ellipsoidal height was determined by GPS observations AQ2646.and is referenced to NAD 83. AQ2646 AQ2646.The geoid height was determined by GEOID03.

GEODETIC INFRASTRUCTURE AQ2646_U.S. NATIONAL GRID SPATIAL ADDRESS: 17RMP (NAD 83) AQ2646_MARKER: F = FLANGE-ENCASED ROD AQ2646_SETTING: 59 = STAINLESS STEEL ROD IN SLEEVE (10 FT.+) AQ2646_SP_SET: STAINLESS STEEL ROD IN SLEEVE AQ2646_STAMPING: FLGPS AQ2646_MARK LOGO: NGS AQ2646_PROJECTION: FLUSH AQ2646_MAGNETIC: N = NO MAGNETIC MATERIAL AQ2646_STABILITY: B = PROBABLY HOLD POSITION/ELEVATION WELL AQ2646_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR AQ2646+SATELLITE: SATELLITE OBSERVATIONS - November 10, 2006 AQ2646_ROD/PIPE-DEPTH: 24.4 meters AQ2646_SLEEVE-DEPTH : 0.9 meters AQ2646 HISTORY - Date Condition Report By AQ2646 HISTORY MONUMENTED NGS AQ2646 HISTORY GOOD AQ2646 HISTORY GOOD AQ2646 HISTORY GOOD NGS AQ2646 HISTORY GOOD KEISCH AQ2646 HISTORY GOOD FLDEP AQ2646 HISTORY GOOD FLDEP AQ2646 HISTORY GOOD FLDEP AQ2646 HISTORY GOOD FLDEP AQ2646 HISTORY GOOD BAKER

GEODETIC INFRASTRUCTURE MODERN FEATURES Continiously Operating Reference Stations (CORS) Raw observations archived and streamed to internet Connection to internet via land lines or cell phone Users can retrieve archived obs for in house post processing Users can submit (on Line) own obs to processing center for post processing of base lines (OPUS)

GEODETIC INFRASTRUCTURE MODERN FEATURES Real Time Applications Single Base Line real time solutions – range limits because of ionospheric effects Virtual Reference Station Technology – eliminates ionospheric effects and serves differential corrections over wide areas Significant improvements in efficiency Automated control over datum usage Powerful tool to migrate spatial data from superseded to current datum Opportunities for online collaboration – Public/Private – Field/Office Autonomous field operations

GEODETIC INFRASTRUCTURE MODERN FEATURES MOORE’S LAW!!!!!!!!!!!!!!!!!!!!!! SERVICE CERTIFICATION TELEMETRY STANDARDS

GEODETIC INFRASTRUCTURE OPERATING EXAMPLE