GPS Survey Equipment GPS Trimble R 6 or

GPS Survey Equipment • • GPS Trimble R 6 or R 8 Legs+Bipod Controller* Base Station or VRS Competencies #1 -5

GPS Survey Equipment

GPS Survey Equipment • How GPS works with satellites Competencies #1

Position Dilution of Precision (PDOP)

Sources of Error • GPS receivers clock accurate to 10 nanoseconds • Signal travels at ‘c’ • Atmospheric Disturbances • Reflections • time drift

GPS Survey Equipment • Satellites send timestamp signals to Earth • 3 satellites required for horizontal • 4 satellites required for vertical • 5 th is required for survey grade Competencies #1

GPS Survey Equipment • Why need phone? Competencies #1

GPS Survey Equipment • Rover plus base station • Why need phone Competencies #1

KYCORS Network

GPS Survey Equipment • Horizontal-Total Station accuracy about the same • Vertical- Total Station generally more accurate Accuracy if not fixed • Does not work properly without “sky” • PDOP, Satellites Competencies #1

Competencies #1

GPS Survey Equipment GPS Equipment Special Issues • Site Calibration • Once per Job • Minimum # control points • 2 big settings • Observed Control Point • Fast shot- Topo • Can’t get close to building (15 degree rule) Competencies #2

Competencies #2

Vertical References

Earth’s Geoid