GPS Survey Equipment

• GPS Trimble R6 or R8• Legs+Bipod• Controller*• Base Station or VRS

Competencies #1-5

GPS Survey Equipment

GPS Equipment Basics•In every office?•Requires only 1 person•Controller Setup

• Datums

•Anyone can get GPS buttons to work, we want QUALITY DATA!

Competencies #1-5

GPS Survey Equipment

GPS Survey Equipment

Competencies #1

•How GPS works with satellites

Position Dilution of Precision (PDOP)

Sources of Error

GPS Survey Equipment

•Satellites send timestamp signals to Earth•3 satellites required for horizontal•4 satellites required for vertical•5th is required for survey grade

Competencies #1

GPS Survey Equipment

Competencies #1

•Why need phone?

GPS Survey Equipment

Competencies #1

•Rover plus base station•Why need phone

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 (15degree rule)

Competencies #2

Competencies #2