3D and 2D radars for open pit slope monitoring - BOHOGS · 2015. 12. 3. · 3D-RAR 2D-SAR 2D-RAR Tactical (targeted) and strategic (broad area) Safety-critical and background monitoring

3D and 2D radars for open pit slope monitoring Albert Cabrejo, Product Manager (GroundProbe)

Acknowledgments

From GroundProbe: • Patrick Bellett – Principal Scientist • David Noon – VP Sales & Operations From LisaLabs • Davide Leva – Principal Scientist • Carlo Rivolta - CEO

Introduction and Background

• Real Aperture Radar (RAR) vs Synthetic Aperture Radar (SAR) • Radar dimensionality – 3D and 2D radars

3D-RAR 2D-SAR 2D-RAR

Tactical (targeted) and strategic (broad area) Safety-critical and background monitoring

Rapid-brittle and slow-ductile failures Bench-scale, multi-bench scale, total slope failures

All radars (3D-RAR, 2D-SAR and 2D-RAR) are capable to monitor all these combinations

Each has particular strengths and trade-offs as well

• Balanced comparison of 3D-RAR, 2D-SAR and 2D-RAR • Co-authors (Drs Bellett, Leva and Rivolta)

MONITORING STRATEGIES EFFECTIVE USES OF SLOPE STABILITY RADAR

Monitoring Strategies

Targeted Monitoring

Broad Area Monitoring

• Monitor known risks and hazards

• Highly mobile • Flexible positioning • Safety-critical for

small/large rapid-brittle failures

• Find new risks and hazards

• Often left at crest or mid-slope

• Longer term monitoring

• Safety-critical and background for large slow failures

Targeted and Broad Area Monitoring Systems

3D Real Aperture Radar (RAR) Dish antenna Pencil beam – small spot on the wall Scans a spot in azimuth and elevation Each spot is also sliced in range Highest confidence for targeted area

2D Synthetic Aperture Radar (SAR) Small antennas on rail

Vertical beam – thin stripe on wall Each stripe segmented by range

Fixed view forward Longest range

Highest resolution

2D Real Aperture Radar (RAR) Long antennas

Vertical beam – thin stripe on wall Each stripe segmented by range

Rotates the stripe in azimuth (fast) Broadest area covered per unit of time

3D-RAR 3D Radar sees the world in 3D and generates a radar 3D DTM

Azimuth°

Ele

vatio

n°

3D-RAR

Azimuth°

Ele

vatio

n°

3D Radar sees the world in 3D and generates a radar 3D DTM and projects naturally to front view

3D-RAR with native front view visualisation

3D-RAR with native 3D visualisation

Photograph draped over 3D radar DTM


Deformation image draped over 3D radar DTM


Photograph & deformation image draped over 3D radar DTM

2D-RAR

Long antennas

Thin, tall, vertical stripe ~0.5° wide and ~60° tall

Tuesday, December 01, 2015 – Commercial in Confidence – 14








2D Radar with natural plan view image

eg. SSR-FX: 60/180 degrees in 2 minutes Azimuth pixels ~ 0.125°/0.5° Range pixels ~ 0.67 m

180°

180°

Broad area monitoring in Plan view



2D-SAR

Small antennas Horizontal translation

The 2D-SAR generates a broad beam that synthesizes narrow beams in a fixed field of view.

eg. SSR-SARx bench-scale at 4.5km range

Long range monitoring 2D-SAR



Long range monitoring 2D-SAR 2mm over 14 days

5mm over 14 days

• 2nd periodical check 6-15 september 2015

Periodic monitoring with 2D-SAR

1st PC 5mm

2nd PC 60mm

Permanent monitoring

Periodic monitoring with 2D-SAR

Conclusions

3D and 2D radars can be used for targeted and broad area monitoring – but each has a strength:

For targeted monitoring of known high risk areas… 3D-RAR provides high confidence for targeted monitoring Front-view display - users can tactically view the slope as if looking

from front-on.

For very broad area monitoring to detect new risk areas …

2D-RAR provides very broad angle coverage quickly Plan-view display - users can strategically view the slope with

reference to other mine geospatial maps (eg. aerial photograph, mine plan, hazards map).

Conclusions

For very long range monitoring … 2D-SAR provides up to 4.5km range over a fixed angle of view

For monitoring slopes with very slow rates of movements… 2D-SAR hardware is easy to relocate and geo-reference so small

movements in-between monitoring periods can be measured.

For some mines, an integrated solution using some or all of

the available radar monitoring technologies (3D-RAR, 2D-SAR and 2D-RAR) together with non-radar monitoring technologies will provide the most comprehensive monitoring strategy

Safety first

Customer focus

Innovative solutions

Honesty and integrity

People matter

Documents

3D and 2D radars for open pit slope monitoring - BOHOGS · 2015. 12. 3. · 3D-RAR 2D-SAR 2D-RAR Tactical (targeted) and strategic (broad area) Safety-critical and background monitoring