J. Anthony Cavell, PLS, CFedSLouisiana State University, C4G

Currently GNSS's are GPS and GLONASS, Galileo is planned

They supplant earlier systems Transit, STARFIX® Omega, LORAN, Decca VOR, Del Norte,

Motorola, Cubic, EDM Microwave (Autotape, MiniRanger, Microfix) Beacons, Lighthouses, Tape, Sextant,

Transit, Compass, Clock

USACE

USACE

USACE

USACE

Differential Two receivers and a reference

Real-Time Differential Two receivers a reference and a radio

National DGPS Coast Guard and Corps beacons WAAS adds to the mix Local networks add value

Static baselines Two or more receivers

Kinematic (poor performance) Post processing risky

Real-Time Kinematic Add radio and reduce risk

Static baselines & Kinematic CORS provide reliable tie to NSRS

Real-Time Kinematic Local networks add precision Ties to NSRS add accuracy

CORS provide confident network tie to NSRS National CORS embedded in Network

Network data supports numerous scientific, engineering and surveying endeavors Geology, Weather, Deformation,

Construction

A challenging environment for surveyors Towers used to extend surveys Radio ranging followed early-on Only private satellite navigation system,

STARFIX® NavBeacon use adopted early Static GPS brought survey control to the marsh Real-time kinematics methods enhanced topo,

subsurface and boundary surveys Subsidence renders benchmarks unreliable!

LSU C4G deploys GULFNet in cooperation with national CORS program

NOAA/NGS reports that La. BM’s “unreliable.”

Seed planted to develop GULFNet Real-Time System (GRTS)

C4G research provided crucial NOAA TR-50 NGS used TR-50 to “validate” 80+ BMs

after Hurricanes Katrina and Rita By 2006 many more stations were added National Weather Service uses GULFNet

data to improve forecasts In 2007 dream of LSU GRTS became reality 2008 LSU C4G, GULFNet and GRTS cover

the borders of the state except offshore.

GULFNet provides better ties to the NSRS

GRTS provides construction, topo, hydro and navigation with heretofore unheard of speed and accuracy

The complex behavior of Louisiana geology will be measurable, reliably

… and much, much more.

J. Anthony Cavell, PLS, CFedSLSU C4G