.: Technology

GDS has collaborated with North American technologists to derive an airborne survey system, which maximizes ground measurement accuracy, density and area while minimizing survey time and ground intrusion. GDS has continued to improve and extend our capabilities by owning, operating and doing research and development in airborne laser survey systems, the only South East Asian company to do so. Airborne laser survey is a technologically and logistically challenging field but GDS strongly believe that our systems and technology through our years of expertise in this field, can contribute effectively and efficiently to any mapping needs. GDS’s latest system is the DVG- Helix, an airborne laser and digital imagery survey system.

• DVG-Helix is a unique aircraft-mounted system that integrates Global Positioning Satellite (GPS) and differential accuracy technology with light detection and ranging technology (LiDAR) and digital imagery technology.

• The unit sends a directed precisely measured laser pulse out of the aircraft by a multifaceted rotating mirror. When an earth feature intercepts the laser pulse, it is reflected back to the aircraft and digitally recorded.

• The unit also has multiple-return capability, allowing the laser beam to penetrate vegetation for bare-earth analysis.

• Our latest success in R&D has allowed fixed wing and helicopter capability.

  GDS can provide the cheapest, fastest and most accurate solutions to client’s problems.

.: Standard Services

• Surface elevation data: x, y and z coordinates

• Highly accurate data delivered in Binary or ASCII format

• Delivery medium: CD-ROM or DVD-ROM

• License and use agreement

.: Value Added Services

• Digital elevation models (DEM)

• Digital terrain models (DTM)

• Building footprints

• Building heights

• Georeferenced Digital Orthorectified Photo Mosaics

• Time stamped Digital Video Imagery

• Digitized features

• Colour draped 3-D images

• Fly through simulation models

.: Capabilities of System

• Highly accurate X, Y and Z values - even in dense forest and steep areas

• High density data collected at airborne speed - over 250,000 points per km˛

• Accurate ground profiles through even the densest forest foliage - GDS's LiDAR technology can penetrate through the smallest gaps between leaves to measure actual ground levels. Other methods that interpolate using estimated tree heights can be 300% inaccurate

• All data is directly measured and processed in digital format - there is no human, accumulation or interpolation error

• Final data can be produced in any format and referenced to any map projection - e.g. Moss Genio, Arc View, Arcinfo, DXF, RSO

• Time-stamped Scouting Video can be produced - providing a visual record over the flown area for presentations and other uses

• DVG surveys are discreet and environmentally friendly - land access permits are unnecessary and there is no ground intrusion through environmentally sensitive areas

• DVG-HELIX is a proven product - unlike many of the airborne laser systems presently in use around the world, DVG-HELIX has a solid track record of over 20 projects completed on time and within budget

• DVG-HELIX is minimally affected by weather – as DVG-HELIX can be flown from 100m to 1000m above ground level. Low clouds, light rain, swamp, etc. do not prevent DVG-HELIX from being highly productive

• DVG- HELIX can be flown to follow terrain features - transmission line and pipeline corridors, highways, railway corridors, rivers, canals, shorelines, canyons and other non-linear features are not dependent on parallel flight lines for area coverage.

• DVG-Helix can fly lower and slower - giving a denser grid of laser postings on the ground than a fixed-wing LiDAR system.

• DVG-Helix does not need to operate out of an airport – it can be based very close to the project area thereby keeping non-productive ferrying times to a bare minimum. This is very advantageous for very remote project areas.

Comparison Of Various Survey Technologies

    DVG-Helix Vs. SRTM Vs. Radarsat-1 Vs SPOT 5