Geodetic Monitoring Solutions in Mining Industry

ASIA GEOSPATIAL FORUM 2011 Pasawat Tipyotha

Application Engineer

Trimble Monitoring Solutions

Information

Trend

+ Time

Common request in all monitoring applications

Trimble Monitoring SolutionsDifferent jobs require different sensors

• Optical Total Stations– High accuracy positioning

– Can observe multiple points

– Relatively short distances <2,5km

• GNSS Sensors– Large distances– High data rate– Precise differential positioning– Limited to one point

New Instrument and TechnologyTrimble S8 with FineLock™

• Angle accuracy: 0.5” or 1”

• Distance accuracy: 0.8 mm + 1 ppm

• FineLock accuracy: <1 mm at 300 m

• Available as Autolock and Robotic

• MagDrive™

• SurePoint™

• Optional Long Range FineLock™

→ Accuracy: <10 mm at 2,500 m

Trimble S8 Total StationFineLock™

• Works with 333 Hz

• One measurement takes two seconds

• Averages 670 aimings per measurement

Manual Aiming!FineLock Aiming in „Slow Motion“!

• Narrow field of view

• No interference with surrounding prisms

• Minimum separation Δ: 80 cm at 200 m

Δ

Trimble S8 Total StationFineLock™

• Optical total stations• GNSS receivers

Applications for GNSS and optical sensors

Trimble 4D Control

• Optical total stations• GNSS receivers• Optical total stations combined with GNSS receivers

Applications for GNSS and optical sensors

Trimble 4D Control

Trimble 4D ControlDesigned for Mining

Displacement based on slope distance measurements

Overview

• Motivation for introducing the separated Slope Distance Measurements.

• Implementation in T4D (Monitor Properties, Slope Distance Chart View, Alarming, Report)

Motivation

Due the atmospheric circumstances we are not able permanently to lock the target prism. Instead of losing information of the point in the current round it would be useful to get at least one usable measurement component from the running round the slope distance.

We are interested into point movements in the instrument direction (some users need exactly this feature)

This kind of displacement should be estimated by comparing the measurements (ReferenceSlopeDistance - CurrentSlopeDistance) but not estimated via the derived coordinates.

Motivation

The monitoring direction is defined with one measurement component only (instrument<->target). no correlation with vertical and horizontal angles.

The uncertainty of measurements is dependent only of Slope Distance Measurements and ppm-Modeling. in case of “target not locked” state we assume that the target point is still near the expected position. So the inaccuracy in the slope distance is much less than e.g. vertical angle.

The adjustment calculation have not effect on the delta values of slope distance measurements.

Motivation

Bad atmospheric circumstances do not allow the instrument to lock the prism. To get at least one valuable measurement component we try to measure the slope distance and keep that as significant value for future analysis. Create difference to the reference slope distance.

Implementation in T4D – UI Data Collector/Data Receiver view

Implementation in T4D – UI 2D Map

Implementation in T4D – UI Displacement Chart View

Implementation in T4D – UI Slope Distance Chart View

(Deformation) Monitor Properties

• Defines thresholds for slope distances

Edit 0.5

Slope distance Thresholds of a point in the group DAM_SOUTH

Alarming

• Create appropriate thresholds via Alarm Manager

• If threshold is exceeded we get appropriate alarm message

Slope Distance Displacement - Report

Slope Distance Displacement - Report

Zurich Central Station, Switzerland

• New rail track• New train station• New tunnel

Real-time optical monitoring!

Examples from the real world

Phalaborwa Copper Mine, South Africa

Examples from the real world

Tolt Dam, U.S.A.

Examples from the real world

Deep Foundation in Monte Carlo, Monaco

Examples from the real world

El Romeral Iron Mine, Chile

Examples from the real world

Example from Real Project in Details

Maemoh Mine, Thailand

Background Information

Mae Moh mine is the largest Lignite coal mine in Thailand Located in Mae Moh district. Distance from Bangkok to the north is about 630 kilometers

More information

• The Maemoh mine serves the Maemoh Power Plant from EGAT. This power plant supplies power to the northern region of Thailand. The mine has been operating for 50 years already. With the more recent expansion the need existed to install a new, additional monitoring system. Within the mine many people are working and many, expensive machinery is deployed. To reduce the risk to both staff and equipment this new monitoring system was needed. Due to the dimension of the mine a long range monitoring solution was needed. The Trimble S8 proved a perfect solution for this.

Problems with the old system

• Using 6 radios including repeaters for transmit the data to control center– Lightening problem– Stability problem

• Keeping Database PCs at site– Risk for robbery– Checking data on site at daily basis– Not flexible

Requirements for the new system

• Sending data including temperature directly from

instrument to the control center• No PCs or laptop kept with the instrument• Able to control the instrument remotely• Monitored points length are up to 2.5 kilometers• Up to 50 points need to be monitored in the pit

New System Diagram

Control points

Monitored Area

Monitoring Hut

Control Center

Conclusions

• Modular setup allows the instruments to be controlled remotely from a control center.

• The Trimble S8 is monitoring approximately 50 points. Trimble’s MagDrive solution helps to improve the speed of measuring all of these compared to conventional servo systems.

• Long Range Finelock for long range measurement reduced the need to install multiple monitoring stations across the mine.

• Use of a wireless LAN system eliminates the problems they experienced with high power radios that required repeaters across the site.

Thank You!