RIEGL VQ-840-GL Versatile Topo-Bathymetric Airborne Laser Scanner

Product Overview

The RIEGL VQ-840-GL is a fully integrated, compact airborne laser scanner designed for combined topographic and bathymetric surveying.

Its lightweight construction and proven form factor support integration with both crewed aircraft and UAVs. The system also offers customer-specific initial configurations and a broad range of parameter settings, allowing operation to be adapted to individual survey missions.

The VQ-840-GL uses a narrow, visible 532 nm green laser beam for high-resolution surveying of underwater topography. Depending on water clarity, the laser can penetrate the water surface and measure submerged targets.

Key Features

• Designed for combined topographic and bathymetric airborne and UAV-based surveying
• Measurement rate up to 200 kHz
• Scan speed up to 100 scans/sec
• 20 mm accuracy
• 15 mm precision
• 532 nm green laser wavelength
• Multiple-target capability
• Echo signal digitization
• Online waveform processing
• Comprehensive full waveform recording
• Full waveform data available for subsequent analysis and waveform averaging
• Optional integrated inertial navigation system
• Optional integrated high-resolution digital camera
• Compact, lightweight, and robust housing
• Compatible with typical aircraft hatches
• Compatible with stabilized platforms

Topo-Bathymetric Measurement

The RIEGL VQ-840-GL performs laser range measurements using a narrow, visible green laser beam emitted from a pulsed laser source.

At the specified 532 nm wavelength, the laser can penetrate water under suitable clarity conditions, enabling the measurement of submerged targets and underwater topography.

Measurement Technology

Distance measurement is based on:

• Time-of-flight measurement
• Very short laser pulses
• Echo digitization
• Online waveform processing

The system also supports multiple-target detection.

For complex target situations containing multiple echo signals, digitized echo waveforms can be stored for subsequent offline full waveform analysis.

Full Waveform Recording

The VQ-840-GL provides concurrent, comprehensive storage of full waveform data for all measurements.

The stored waveform information can subsequently be used for:

• Full waveform analysis
• Waveform averaging

Elliptic Scan Pattern

The scanner deflects the laser beam using an elliptic scan pattern.

This causes the beam to reach the water surface at an incidence angle with relatively low variation, supporting bathymetric data acquisition.

Navigation and Camera Options

The VQ-840-GL can optionally be complemented by an inertial navigation sensor for subsequent estimation of the scanner’s position and orientation.

A high-resolution digital camera can also be optionally integrated to supplement the LiDAR survey data.

Airborne Integration

The scanner’s compact and lightweight construction supports integration with:

• UAVs
• Crewed aircraft
• Stabilized airborne platforms

Its rugged internal mechanical structure and dust- and splash-water-proof housing support extended airborne operation.

Technical Data Overview

Performance

The RIEGL VQ-840-GL provides measurement rates up to 200 kHz and scan speeds up to 100 scans/sec.

Across the listed operating modes, the scanner provides:

• 20 mm accuracy
• 15 mm precision
• Minimum range of 20 m
• Water-depth penetration up to 2.0 Secchi depths

Main Applications

The RIEGL VQ-840-GL is intended for:

• Coastline and Shallow Water Mapping
• Detection of Submerged and Floating Targets
• Surveying for Hydraulic Engineering
• Hydro-Archaeological Surveying
• River Surveying
• Repeated Survey of Water Reservoirs

Software

RIEGL provides the following software packages for the RIEGL VQ-840-GL:

• RiPROCESS
• RiACQUIRE
• RiUNITE

For processing scan data acquired with RIEGL hydrography laser scanners, RiHYDRO is available as an AddOn to RiPROCESS.

The software environment is further complemented by:

• RiVLib
• RDBLib
• RiMAP Plugin for ArcGIS