GNSS Monitoring

The Department of Water Affairs in South Africa expands Dam Monitoring to GPS/GNSS Deformation Monitoring

Trimble - NetR5 receiver - Zephyr Geodetic Antenna

DELL T310 Server Poynting WIFIRB411 panel Antenna

Sector 90 deg Antenna

Omni 360 deg Antenna VSAT Antenna SkyEdge Modem

GNSS BASIC EQUIPMENT

BASIC GNSS SETUP CREST OF DAM WALL

TYPICAL GNSS REFERENCE STATION

Zephyr Geodetic Antenna3rd Arch Stompdrift dam

Omni 360 deg AntennaRoode Els Berg dam

GNSS Monitoring LayoutDuivenhoks Dam

GNSS Monitoring LayoutStompdrift Dam

GNSS Monitoring LayoutKouga Dam

GNSS Monitoring LayoutRoode Els Berg Dam

Some Key features of Trimble 4D ControlPost Processing Monitoring

• Computation and analysis of sensor displacement

• Axis Rotation – computation and display of displacements along a user defined

• Displacement charts and tables

• User defined tolerance settings Instant notification of deformations that exceed he pre-set tolerance values.

• Alarm Manager – Real time warnings and alerts via email Real time warnings and alerts via email

• Remote login to view and control the system

Kouga dam - Left Flank Crest1 Hour Post Processing Graph

Kouga dam - Right Flank Crest6 Hour Post Processing Graph

GNSS Reference station coordinates derived from Geodetic Deformation results

Roode Els Berg Dam

Station Date Y X dy dx (m) (m) (m) (m)

P01 22/02/2012 205.2479 400.8471 P01 17/02/2013 205.2495 400.8486 +0.0016

+0.0015 Mean 205.2487 400.8478

P03 22/02/2012 -86.0861 252.9499 P03 17/02/2013 -86.0854 252.9516 +0.0007

+0.0017 Mean -86.0858 252.9508

Computed local GNSS co-ordinates of secondary GNSS pillars on crest of dam

Roode Els Berg Dam

Station Date Y X (m) (m)

P203 22/02/2012 GNSS -38.9167 27.0547 22/02/2012 Geodetic -38.9169 27.0540 Diff -0.0002 -0.0007

P203 18/02/2013 GNSS -38.9176 27.0532 19/02/2013 Geodetic -38.9172 27.0545 Diff +0.0004 +0.0013

P206 22/02/2012 GNSS 36.0821 26.9494 22/02/2013 Geodetic 36.0819 26.9488 Diff -0.0002 -0.0006

P206 18/02/2013 GNSS 36.0811 26.9492 19/02/2013 Geodetic 36.0815 26.9499 Diff +0.0004 +0.0007

GNSS vs GEODETIC Deformations at Roode Els Berg dam

Temperature and Water Level

Up/Downstream GNSS Deformations

GNSS vs GEODETIC Deformations at Roode Els Berg dam

Temperature and Water Level

Left/Right Flank GNSS Deformations